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<!doctype html> <html> <head> <meta charset="utf-8"/> <meta name="viewport" content="width=device-width, initial-scale=1"/> <title>ET: Agents</title> <link media="all" rel="stylesheet" href="/theme/responsive-eiffel-org/css/all.css" /> <link rel="shortcut icon" href="https://www.eiffel.org/favicon.ico"/> <link href="https://fonts.googleapis.com/css?family=Inconsolata|Open+Sans:400,700|Titillium+Web" rel="stylesheet" type="text/css" />  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script> <link rel="stylesheet" href="/module/auth/files/css/auth.css" type="text/css"/> <link rel="stylesheet" href="/module/node/files/css/node.css" type="text/css"/> <link rel="stylesheet" href="/module/blog/files/css/blog.css" type="text/css"/> <link rel="stylesheet" href="/module/comments/files/css/comments.css" type="text/css"/> <link rel="stylesheet" href="/module/wikitext/files/css/wikitext.css" type="text/css"/> <link rel="stylesheet" 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href="/doc/eiffel/Learning_Eiffel">Learning Eiffel</a></li><li><a href="/doc/eiffel/Common_myths_and_misconceptions_about_Eiffel">Common myths and misconceptions about Eiffel</a></li></ul></li><li class="expandable expanded "><a href="/doc/eiffel/Eiffel_Tutorials">Tutorials</a><ul> <li class="expandable "><a href="/doc/eiffel/Invitation_to_Eiffel_%28I2E%29">Invitation to Eiffel</a><ul> <li><a href="/doc/eiffel/I2E-_What_Must_I_Know_First%3F">I2E: What Must I Know First?</a></li><li><a href="/doc/eiffel/I2E-_Design_Principles">I2E: Design Principles</a></li><li><a href="/doc/eiffel/I2E-_Object-Oriented_Design">I2E: Object-Oriented Design</a></li><li><a href="/doc/eiffel/I2E-_Classes">I2E: Classes</a></li><li><a href="/doc/eiffel/I2E-_Types">I2E: Types</a></li><li><a href="/doc/eiffel/I2E-_Design_by_Contract_and_Assertions">I2E: Design by Contract and Assertions</a></li><li><a href="/doc/eiffel/I2E-_Exceptions">I2E: Exceptions</a></li><li><a href="/doc/eiffel/I2E-_Event-Driven_Programming_and_Agents">I2E: Event-Driven Programming and Agents</a></li><li><a href="/doc/eiffel/I2E-_Genericity">I2E: Genericity</a></li><li><a href="/doc/eiffel/I2E-_Inheritance">I2E: Inheritance</a></li><li><a href="/doc/eiffel/I2E-_Polymorphism_and_Dynamic_Binding">I2E: Polymorphism and Dynamic Binding</a></li><li><a href="/doc/eiffel/I2E-_Combining_Genericity_and_Inheritance">I2E: Combining Genericity and Inheritance</a></li><li><a href="/doc/eiffel/I2E-_Deferred_Classes_and_Seamless_Development">I2E: Deferred Classes and Seamless Development</a></li><li><a href="/doc/eiffel/I2E-_Putting_a_System_Together">I2E: Putting a System Together</a></li><li><a href="/doc/eiffel/I2E-_Invitation_to_Eiffel_Copyright">I2E: Invitation to Eiffel Copyright</a></li></ul></li><li class="expandable "><a href="/doc/eiffel/Mini_How-tos">Mini How-tos</a><ul> <li><a href="/doc/eiffel/Getting_a_STRING_from_a_NUMERIC_object">NUMERIC to STRING</a></li><li><a href="/doc/eiffel/Iterating_on_a_LIST">Iterating on a LIST</a></li><li><a href="/doc/eiffel/Removing_object_while_iterating_on_a_LIST">Removing object while iterating on a LIST</a></li><li><a href="/doc/eiffel/Managing_CTRL%2BC_in_console_application">Managing CTRL+C in console application</a></li></ul></li><li class="expandable expanded "><a href="/doc/eiffel/An_Eiffel_Tutorial_%28ET%29">Tutorial</a><ul> <li><a href="/doc/eiffel/ET-_Overview">ET: Overview</a></li><li><a href="/doc/eiffel/ET-_General_Properties">ET: General Properties</a></li><li><a href="/doc/eiffel/ET-_The_Software_Process_in_Eiffel">ET: The Software Process in Eiffel</a></li><li><a href="/doc/eiffel/ET-_Hello_World">ET: Hello World</a></li><li><a href="/doc/eiffel/ET-_The_Static_Picture-_System_Organization">ET: The Static Picture: System Organization</a></li><li><a href="/doc/eiffel/ET-_The_Dynamic_Structure-_Execution_Model">ET: The Dynamic Structure: Execution Model</a></li><li><a href="/doc/eiffel/ET-_Genericity_and_Arrays">ET: Genericity and Arrays</a></li><li><a href="/doc/eiffel/ET-_Design_by_Contract_%28tm%29%2C_Assertions_and_Exceptions">ET: Design by Contract (tm), Assertions and Exceptions</a></li><li><a href="/doc/eiffel/ET-_Inheritance">ET: Inheritance</a></li><li><a href="/doc/eiffel/ET-_Instructions">ET: Instructions</a></li><li><a href="/doc/eiffel/ET-_Once_routines_and_shared_objects">ET: Once routines and shared objects</a></li><li><a href="/doc/eiffel/ET-_Other_Mechanisms">ET: Other Mechanisms</a></li><li class="active "><a href="/doc/eiffel/ET-_Agents">ET: Agents</a></li><li><a href="/doc/eiffel/ET-_Lexical_Conventions_and_Style_Rules">ET: Lexical Conventions and Style Rules</a></li><li><a href="/doc/eiffel/ET-_To_Learn_More">ET: To Learn More</a></li><li><a href="/doc/eiffel/ET-_Eiffel_Tutorial_Copyright">ET: Eiffel Tutorial Copyright</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffel/Language_reference">Language</a><ul> <li class="expandable "><a href="/doc/eiffel/Quick_reference_to_the_Eiffel_programming_language">Quick Reference</a><ul> <li><a href="/doc/eiffel/Eiffel_programming_language_syntax">Syntax</a></li><li class="expandable "><a href="/doc/eiffel/Expressions">Expressions</a><ul> <li><a href="/doc/eiffel/Conditional_expression">Conditional</a></li><li><a href="/doc/eiffel/Manifest_array">Manifest array</a></li></ul></li><li><a href="/doc/eiffel/Types">Types</a></li><li><a href="/doc/eiffel/Eiffel_programming_language_reserved_words">Reserved words</a></li></ul></li><li class="expandable "><a href="/doc/eiffel/Void-safe_programming_in_Eiffel">Void-safe programming</a><ul> <li><a href="/doc/eiffel/Void-safety-_Background%2C_definition%2C_and_tools">Background and tools</a></li><li><a href="/doc/eiffel/Creating_a_new_void-safe_project">New void-safe project</a></li><li class="expandable "><a href="/doc/eiffel/Converting_existing_software_to_void-safety">Converting existing software to void-safety</a><ul> <li><a href="/doc/eiffel/Void-safe_changes_to_Eiffel_libraries">Void-safe changes to Eiffel libraries</a></li><li><a href="/doc/eiffel/Mixing_void-safe_and_void-unsafe_software">Mixing void-safe and void-unsafe software</a></li></ul></li><li><a href="/doc/eiffel/What_makes_a_Certified_Attachment_Pattern">What makes a Certified Attachment Pattern</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffel/Technical_papers_about_Eiffel">Papers</a><ul> <li><a href="/doc/eiffel/Eiffel_as_an_expression_language">Eiffel as an expression language</a></li><li><a href="/doc/eiffel/Void-safety-_how_Eiffel_removes_null-pointer_dereferencing">Void-safety: how Eiffel removes null-pointer dereferencing</a></li><li class="expandable "><a href="/doc/eiffel/Books_about_the_Eiffel_Method_and_Language">Books</a><ul> <li><a href="/doc/eiffel/Touch_of_Class-_Learning_to_Program_Well_with_Objects_and_Contracts">Touch of Class</a></li><li><a href="/doc/eiffel/Object-Oriented_Software_Construction%2C_2nd_Edition">OOSC2</a></li><li><a href="/doc/eiffel/ECMA_Standard_367">ECMA Standard 367</a></li><li><a href="/doc/eiffel/Eiffel-_The_Language">Eiffel: The Language</a></li><li><a href="/doc/eiffel/Reusable_Software-_The_Base_Object-Oriented_Component_Libraries">OO Component Libraries</a></li><li><a href="/doc/eiffel/EiffelStudio-_A_Guided_Tour_-_Eiffel_Software_Technical_Report">EiffelStudio Guided Tour</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffel/Coding_Standards">Coding Standards</a><ul> <li><a href="/doc/eiffel/Eiffel_Code_Comments">Eiffel Code Comments</a></li><li><a href="/doc/eiffel/Eiffel_Coding_Standard">Eiffel Coding Standard</a></li><li><a href="/doc/eiffel/Local_Declaration_Guidelines">Local Declaration Guidelines</a></li><li><a href="/doc/eiffel/Style_Guidelines">Style Guidelines</a></li></ul></li><li class="expandable "><a href="/doc/eiffel/Examples">Examples</a><ul> <li><a href="/doc/eiffel/Introduction_to_the_Examples_Book">Introduction to the Examples Book</a></li><li><a href="/doc/eiffel/Example-_Command_line_arguments">Example: Command line arguments</a></li><li><a href="/doc/eiffel/Example-_Environment_variables">Example: Environment variables</a></li><li><a href="/doc/eiffel/Example-_File_IO">Example: File IO</a></li><li><a href="/doc/eiffel/Example-_Polymorphism">Example: Polymorphism</a></li><li><a href="/doc/eiffel/Example-_Reverse_a_string">Example: Reverse a string</a></li><li><a href="/doc/eiffel/Example-_Self-initializing_attributes_and_assigner_commands">Example: Self-initializing attributes and assigner commands</a></li><li><a href="/doc/eiffel/Example-_Sieve_of_Eratosthenes">Example: Sieve of Eratosthenes</a></li><li><a href="/doc/eiffel/Example-_Sleep">Example: Sleep</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio">EiffelStudio</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Getting_started">Getting started</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Setup_and_installation">Setup and installation</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Software_Installation_for_EiffelStudio">Software Installation for EiffelStudio</a><ul> <li><a href="/doc/eiffelstudio/FreeBSD">FreeBSD</a></li><li><a href="/doc/eiffelstudio/HP_OpenVMS">HP OpenVMS</a></li><li><a href="/doc/eiffelstudio/HP_Tru64_UNIX">HP Tru64 UNIX</a></li><li><a href="/doc/eiffelstudio/HP-UX">HP-UX</a></li><li><a href="/doc/eiffelstudio/Linux">Linux</a></li><li><a href="/doc/eiffelstudio/Mac_OS_X">Mac OS X</a></li><li><a href="/doc/eiffelstudio/OpenBSD">OpenBSD</a></li><li><a href="/doc/eiffelstudio/SGI_Irix">SGI Irix</a></li><li><a href="/doc/eiffelstudio/Solaris">Solaris</a></li><li class="expandable "><a href="/doc/eiffelstudio/Windows">Windows</a><ul> <li><a href="/doc/eiffelstudio/Installing_Microsoft_C_compiler">MS C compiler</a></li></ul></li></ul></li><li><a href="/doc/eiffelstudio/Third_Party_Tools_Installation_Help">Third Party Tools Installation Help</a></li></ul></li><li><a href="/doc/eiffelstudio/Introducing_EiffelStudio">Introducing EiffelStudio</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_tutorials">Tutorials</a><ul> <li><a href="/doc/eiffelstudio/Copying_the_Example_Files">Copying the Example Files</a></li><li><a href="/doc/eiffelstudio/Starting_EiffelStudio_and_Opening_a_Project">Starting EiffelStudio and Opening a Project</a></li><li><a href="/doc/eiffelstudio/Compiling_and_Executing_a_System">Compiling and Executing a System</a></li><li><a href="/doc/eiffelstudio/A_Look_at_the_Project_Directory">A Look at the Project Directory</a></li><li><a href="/doc/eiffelstudio/Starting_To_Browse">Starting To Browse</a></li><li><a href="/doc/eiffelstudio/Viewing_Classes">Viewing Classes</a></li><li><a href="/doc/eiffelstudio/Customizing_the_tools_layout_and_toolbars">Customizing the tools layout and toolbars</a></li><li><a href="/doc/eiffelstudio/Producing_and_Exporting_Documentation">Producing and Exporting Documentation</a></li><li><a href="/doc/eiffelstudio/Browsing_Features">Browsing Features</a></li><li><a href="/doc/eiffelstudio/Retargeting_Through_Pick-and-Drop">Retargeting Through Pick-and-Drop</a></li><li><a href="/doc/eiffelstudio/Recompiling_and_Editing">Recompiling and Editing</a></li><li><a href="/doc/eiffelstudio/Handling_Syntax_and_Validity_Errors">Handling Syntax and Validity Errors</a></li><li><a href="/doc/eiffelstudio/Debugging_and_Run-time_Monitoring">Debugging and Run-time Monitoring</a></li><li class="expandable "><a href="/doc/eiffelstudio/Using_AutoTest">Using AutoTest</a><ul> <li><a href="/doc/eiffelstudio/Testing-_Background_and_basics">Testing: Background and basics</a></li><li><a href="/doc/eiffelstudio/Create_a_manual_test">Create a manual test</a></li><li><a href="/doc/eiffelstudio/Execute_tests">Execute tests</a></li><li><a href="/doc/eiffelstudio/Using_extracted_tests">Using extracted tests</a></li><li><a href="/doc/eiffelstudio/Using_generated_tests">Using generated tests</a></li><li><a href="/doc/eiffelstudio/Managing_tests">Managing tests</a></li></ul></li><li><a href="/doc/eiffelstudio/Computing_Project_Metrics">Computing Project Metrics</a></li><li><a href="/doc/eiffelstudio/Graphics-based_Design">Graphics-based Design</a></li><li><a href="/doc/eiffelstudio/Using_automatic_class_licensing">Using automatic class licensing</a></li><li><a href="/doc/eiffelstudio/How_EiffelStudio_Compiles">How EiffelStudio Compiles</a></li><li><a href="/doc/eiffelstudio/Technical_papers_about_EiffelStudio">Papers</a></li><li><a href="/doc/eiffelstudio/The_Command-Line_Compiler">The Command-Line Compiler</a></li><li><a href="/doc/eiffelstudio/Executing_a_System_Within_and_Without_EiffelStudio">Executing a System Within and Without EiffelStudio</a></li><li><a href="/doc/eiffelstudio/Writing_Documentation_Filters_with_EFF%2C_the_Eiffel_Filter_Format">Writing Filters with EFF</a></li><li><a href="/doc/eiffelstudio/Manual_identification_and_copyright">Manual identification and copyright</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_Reference">Reference</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_release_notes">Release Notes</a><ul> <li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_24.05">24.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_23.09">23.09</a></li><li class="expandable "><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_22.12">22.12</a><ul> <li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_22.12_-_macosx">22.12 - macosx</a></li></ul></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_22.05">22.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_21.11">21.11</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_20.11">20.11</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_20.05">20.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_19.12">19.12</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_19.05">19.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_18.11">18.11</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_18.07">18.07</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_18.01">18.01</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_17.05">17.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_17.01">17.01</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_16.05">16.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_15.12">15.12</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_15.08">15.08</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_15.01">15.01</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_14.05">14.05</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_13.11">13.11</a></li><li class="expandable "><a href="/doc/eiffelstudio/7.x">7.x</a><ul> <li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_7.3">7.3</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_7.2">7.2</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_7.1">7.1</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_7.0">7.0</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_6_release_notes">6.x</a><ul> <li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.8">6.8</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.7">6.7</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.6">6.6</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.5">6.5</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.4">6.4</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.3">6.3</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.2">6.2</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.1">6.1</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_6.0">6.0</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_5_release_notes">5.x</a><ul> <li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.7">5.7</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.6">5.6</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.5">5.5</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.4">5.4</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.3">5.3</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.2">5.2</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.1">5.1</a></li><li><a href="/doc/eiffelstudio/Release_notes_for_EiffelStudio_5.0">5.0</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio-_General_interface_description">General Description</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_interface_mechanisms">EiffelStudio interface mechanisms</a><ul> <li><a href="/doc/eiffelstudio/Pick-and-drop_mechanism">Pick-and-drop mechanism</a></li><li><a href="/doc/eiffelstudio/Pick-and-drop_shortcut">Pick-and-drop shortcut</a></li><li><a href="/doc/eiffelstudio/Toolbar_customization">Toolbar customization</a></li></ul></li><li><a href="/doc/eiffelstudio/EiffelStudio-_All_shortcuts">EiffelStudio: All shortcuts</a></li><li><a href="/doc/eiffelstudio/EiffelStudio_window_overview">EiffelStudio window overview</a></li><li><a href="/doc/eiffelstudio/Main_toolbars">Main toolbars</a></li><li><a href="/doc/eiffelstudio/EiffelStudio-_Key_shortcuts">EiffelStudio: Key shortcuts</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Browsing_tools">Browsing tools</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Address_bars">Address bars</a><ul> <li><a href="/doc/eiffelstudio/Main_address_bar">Main address bar</a></li><li><a href="/doc/eiffelstudio/Context_tool_address_bar">Context tool address bar</a></li><li><a href="/doc/eiffelstudio/Change_data_share_mode">Change data share mode</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Groups_tool">Groups tool</a><ul> <li><a href="/doc/eiffelstudio/System_tree_representation">System tree representation</a></li><li><a href="/doc/eiffelstudio/New_cluster_command">New cluster command</a></li><li><a href="/doc/eiffelstudio/New_class_command">New class command</a></li><li><a href="/doc/eiffelstudio/Locate_command">Locate command</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Features_tool">Features tool</a><ul> <li><a href="/doc/eiffelstudio/Feature_tree">Feature tree</a></li><li><a href="/doc/eiffelstudio/New_feature_command">New feature command</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Favorites_tool">Favorites tool</a><ul> <li><a href="/doc/eiffelstudio/Favorites_tree">Favorites tree</a></li><li><a href="/doc/eiffelstudio/Favorites_menu">Favorites menu</a></li><li class="expandable "><a href="/doc/eiffelstudio/Organize_Favorites_dialog">Organize Favorites dialog</a><ul> <li><a href="/doc/eiffelstudio/New_favorite_class_command">New favorite class command</a></li><li><a href="/doc/eiffelstudio/Create_favorite_folder_command">Create favorite folder command</a></li><li><a href="/doc/eiffelstudio/Move_to_Folder_command">Move to Folder command</a></li><li><a href="/doc/eiffelstudio/Remove_favorite_command">Remove favorite command</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Windows_tool">Windows tool</a><ul> <li><a href="/doc/eiffelstudio/Window_list">Window list</a></li><li><a href="/doc/eiffelstudio/Window_menu">Window menu</a></li><li><a href="/doc/eiffelstudio/Window_related_commands">Window related commands</a></li></ul></li><li><a href="/doc/eiffelstudio/Search_tool">Search tool</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_Editor">Editor</a><ul> <li><a href="/doc/eiffelstudio/Cursor_moves">Cursor moves</a></li><li><a href="/doc/eiffelstudio/Selection">Selection</a></li><li><a href="/doc/eiffelstudio/Clipboard_functionality">Clipboard functionality</a></li><li><a href="/doc/eiffelstudio/History_functionality">History functionality</a></li><li><a href="/doc/eiffelstudio/Search_functionality">Search functionality</a></li><li class="expandable "><a href="/doc/eiffelstudio/Automatic_completion">Automatic completion</a><ul> <li><a href="/doc/eiffelstudio/Syntax_auto_complete">Syntax auto complete</a></li><li><a href="/doc/eiffelstudio/Feature_call_auto_complete">Feature call auto complete</a></li><li><a href="/doc/eiffelstudio/Class_name_auto_complete">Class name auto complete</a></li></ul></li><li><a href="/doc/eiffelstudio/Code_Templates">Code Templates</a></li><li class="expandable "><a href="/doc/eiffelstudio/Operations_on_text_blocks">Operations on text blocks</a><ul> <li><a href="/doc/eiffelstudio/Comment_and_uncomment_lines">Comment and uncomment lines</a></li><li><a href="/doc/eiffelstudio/Indent_and_unindent_selection">Indent and unindent selection</a></li><li><a href="/doc/eiffelstudio/Embed_lines_in_%27if_then...end%27_or_in_%27debug...end%27">Embed lines in 'if then...end' or in 'debug...end'</a></li></ul></li><li><a href="/doc/eiffelstudio/Edit_menu_commands">Edit menu commands</a></li><li><a href="/doc/eiffelstudio/Editor_customization">Editor customization</a></li></ul></li><li><a href="/doc/eiffelstudio/Contract_Editor_tool">Contract Editor tool</a></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio-_Project_settings_window">Project Settings</a><ul> <li><a href="/doc/eiffelstudio/System_Options">System Options</a></li><li class="expandable "><a href="/doc/eiffelstudio/General_Target_Options">General Target Options</a><ul> <li><a href="/doc/eiffelstudio/Language_and_Capabilities">Language and Capabilities</a></li><li><a href="/doc/eiffelstudio/Assertion_Options">Assertion Options</a></li><li><a href="/doc/eiffelstudio/Group_Options">Group Options</a></li><li class="expandable "><a href="/doc/eiffelstudio/Advanced_Options">Advanced Options</a><ul> <li><a href="/doc/eiffelstudio/Warning_Options">Warning Options</a></li><li><a href="/doc/eiffelstudio/Debug_Options">Debug Options</a></li><li><a href="/doc/eiffelstudio/Externals_Options">Externals Options</a></li><li><a href="/doc/eiffelstudio/Tasks_Options">Tasks Options</a></li><li><a href="/doc/eiffelstudio/Variables">Variables</a></li><li><a href="/doc/eiffelstudio/Type_mapping">Type mapping</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Compiler">Compiler</a><ul> <li><a href="/doc/eiffelstudio/Melting_Ice_Technology">Melting Ice Technology</a></li><li><a href="/doc/eiffelstudio/Supported_C_compilers">Supported C compilers</a></li><li class="expandable "><a href="/doc/eiffelstudio/Command_line">Command line</a><ul> <li><a href="/doc/eiffelstudio/Eiffel_compatibility_options">Eiffel compatibility options</a></li><li><a href="/doc/eiffelstudio/EiffelStudio-_Using_command_line_options">Using command line options</a></li><li><a href="/doc/eiffelstudio/Batch_compilation">Batch compilation</a></li><li class="expandable "><a href="/doc/eiffelstudio/Command_line_interactive_mode">Command line interactive mode</a><ul> <li><a href="/doc/eiffelstudio/Compile_%28and_run%29_menu">Compile (and run) menu</a></li><li><a href="/doc/eiffelstudio/Class_menu">Class menu</a></li><li><a href="/doc/eiffelstudio/Feature_menu">Feature menu</a></li><li><a href="/doc/eiffelstudio/System_menu">System menu</a></li><li><a href="/doc/eiffelstudio/Testing_menu">Testing menu</a></li><li><a href="/doc/eiffelstudio/Profile_menu">Profile menu</a></li><li><a href="/doc/eiffelstudio/Documentation_menu">Documentation menu</a></li></ul></li><li><a href="/doc/eiffelstudio/finish_freezing_utility">finish_freezing utility</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Dynamic_library_generation">Dynamic library generation</a><ul> <li><a href="/doc/eiffelstudio/Dynamic_library_builder">Dynamic library builder</a></li><li><a href="/doc/eiffelstudio/Definition_file">Definition file</a></li><li><a href="/doc/eiffelstudio/Dynamic_library-_Generated_files">Dynamic library: Generated files</a></li></ul></li><li><a href="/doc/eiffelstudio/Syntax_level_variant_settings_by_version">Syntax level variant settings by version</a></li><li><a href="/doc/eiffelstudio/Differences_between_standard_ECMA-367_and_Eiffel_Software_implementation">ECMA-367 vs implementation</a></li><li><a href="/doc/eiffelstudio/Differences_between_ETL_2nd_printing_and__Eiffel_Software__implementation">ETL 2nd printing vs implementation</a></li><li class="expandable "><a href="/doc/eiffelstudio/Compiler_History">Compiler History</a><ul> <li><a href="/doc/eiffelstudio/Major_changes_with_ISE_Eiffel_18.01_and_18.07">18.07</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_15.12_and_ISE_Eiffel_16.05">16.05</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_15.08_and_ISE_Eiffel_15.12">15.12</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_15.01_and_ISE_Eiffel_15.08">15.08</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_13.11_and_ISE_Eiffel_14.05">14.05</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_7.3_and_ISE_Eiffel_13.11">13.11</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_7.2_and_ISE_Eiffel_7.3">7.3</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_7.1_and_ISE_Eiffel_7.2">7.2</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_7.0_and_ISE_Eiffel_7.1">7.1</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.8_and_ISE_Eiffel_7.0">7.0</a></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_6_compiler_history">6.x</a><ul> <li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.7_and_ISE_Eiffel_6.8">6.8</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.6_and_ISE_Eiffel_6.7">6.7</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.5_and_ISE_Eiffel_6.6">6.6</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.4_and_ISE_Eiffel_6.5">6.5</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.3_and_ISE_Eiffel_6.4">6.4</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.2_and_ISE_Eiffel_6.3">6.3</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.1_and_ISE_Eiffel_6.2">6.2</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_6.0_and_ISE_Eiffel_6.1">6.1</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.7_and_ISE_Eiffel_6.0">6.0</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_5_compiler_history">5.x</a><ul> <li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.6_and_ISE_Eiffel_5.7">5.7</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.5_and_ISE_Eiffel_5.6">5.6</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.4_and_ISE_Eiffel_5.5">5.5</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.3_and_ISE_Eiffel_5.4">5..4</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.2_and_ISE_Eiffel_5.3">5.3</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.1_and_ISE_Eiffel_5.2">5.2</a></li><li><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_5.0_and_ISE_Eiffel_5.1">5.1</a></li><li class="expandable "><a href="/doc/eiffelstudio/Major_changes_between_ISE_Eiffel_4.5_and_ISE_Eiffel_5.0">5.0</a><ul> <li><a href="/doc/eiffelstudio/Assertions_checking_configuration_changes">Assertions checking configuration changes</a></li><li><a href="/doc/eiffelstudio/EiffelThread_differences_from_4.5_to_5.0">EiffelThread differences from 4.5 to 5.0</a></li><li><a href="/doc/eiffelstudio/Compiler_differences_from_4.5_to_5.0">Compiler differences from 4.5 to 5.0</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Errors_and_warnings">Errors, warnings</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Legacy_code">Legacy code</a><ul> <li><a href="/doc/eiffelstudio/VD81">VD81</a></li><li><a href="/doc/eiffelstudio/VWMA%281%29">VWMA(1)</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Code_Analyzer">Code Analyzer</a><ul> <li><a href="/doc/eiffelstudio/Getting_Started">Getting Started</a></li><li><a href="/doc/eiffelstudio/Running_the_Code_Analyzer">Running the Analyzer</a></li><li><a href="/doc/eiffelstudio/Code_Analyzer-_Interpreting_Results">Interpreting Results</a></li><li><a href="/doc/eiffelstudio/Code_Analyzer-_Customization">Customization</a></li><li class="expandable "><a href="/doc/eiffelstudio/Code_Analyzer-_Rules">Rules</a><ul> <li><a href="/doc/eiffelstudio/CA001_-_Self_Assignment">CA001</a></li><li><a href="/doc/eiffelstudio/CA002_-_Unused_argument">CA002</a></li><li><a href="/doc/eiffelstudio/CA003_-_Feature_never_called">CA003</a></li><li><a href="/doc/eiffelstudio/CA004_-_Command-Query_Separation">CA004</a></li><li><a href="/doc/eiffelstudio/CA005_-_Useless_object_test_local">CA005</a></li><li><a href="/doc/eiffelstudio/CA006_-_Object_test_typing_not_needed">CA006</a></li><li><a href="/doc/eiffelstudio/CA010_-_High_complexity_of_nested_branches_and_loops">CA010</a></li><li><a href="/doc/eiffelstudio/CA011_-_Too_many_arguments">CA011</a></li><li><a href="/doc/eiffelstudio/CA013_-_Exported_creation_procedure">CA013</a></li><li><a href="/doc/eiffelstudio/CA017_-_Empty_conditional">CA017</a></li><li><a href="/doc/eiffelstudio/CA020_-_Variable_not_read_after_assignment">CA020</a></li><li><a href="/doc/eiffelstudio/CA023_-_Unneeded_parentheses">CA023</a></li><li><a href="/doc/eiffelstudio/CA024_-_Use_across_loop">CA024</a></li><li><a href="/doc/eiffelstudio/CA025_-_Use_semicolons">CA025</a></li><li><a href="/doc/eiffelstudio/CA028_-_Combine_two_if_instructions">CA028</a></li><li><a href="/doc/eiffelstudio/CA032_-_Long_routine_implementation">CA032</a></li><li><a href="/doc/eiffelstudio/CA033_-_Large_class">CA033</a></li><li><a href="/doc/eiffelstudio/CA034_-_High_NPATH_complexity">CA034</a></li><li><a href="/doc/eiffelstudio/CA071_-_Self-comparison">CA071</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Debugger">Debugger</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Execution_commands">Execution commands</a><ul> <li><a href="/doc/eiffelstudio/Run_and_stop_at_breakpoints">Run and stop at breakpoints</a></li><li><a href="/doc/eiffelstudio/Run_with_arguments">Run with arguments</a></li><li><a href="/doc/eiffelstudio/Execution_profiles">Execution profiles</a></li><li><a href="/doc/eiffelstudio/Run_without_breakpoints">Run without breakpoints</a></li><li><a href="/doc/eiffelstudio/Run_a_finalized_executable">Run a finalized executable</a></li><li><a href="/doc/eiffelstudio/Step_into_a_feature">Step into a feature</a></li><li><a href="/doc/eiffelstudio/Execute_one_line_at_a_time">Execute one line at a time</a></li><li><a href="/doc/eiffelstudio/Step_out_of_a_feature">Step out of a feature</a></li><li><a href="/doc/eiffelstudio/Pause_an_application">Pause an application</a></li><li><a href="/doc/eiffelstudio/Stop_a_debugged_application">Stop a debugged application</a></li><li><a href="/doc/eiffelstudio/Attach_application">Attach application</a></li><li><a href="/doc/eiffelstudio/Detach_application">Detach application</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Breakpoints">Breakpoints</a><ul> <li><a href="/doc/eiffelstudio/Breakpoint_editing">Breakpoint editing</a></li><li><a href="/doc/eiffelstudio/Breakpoint_commands">Breakpoint commands</a></li><li><a href="/doc/eiffelstudio/Breakpoint_information_command">Breakpoint information command</a></li><li><a href="/doc/eiffelstudio/Breakpoint_menu">Breakpoint menu</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Call_stack_tool">Call stack tool</a><ul> <li><a href="/doc/eiffelstudio/Call_stack_tool-_Interface">Call stack tool: Interface</a></li><li><a href="/doc/eiffelstudio/Information_relative_to_a_stack_element">Information relative to a stack element</a></li><li><a href="/doc/eiffelstudio/Supported_exceptions">Supported exceptions</a></li><li><a href="/doc/eiffelstudio/Save_call_stack">Save call stack</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Execution_record_and_replay">Execution record and replay</a><ul> <li><a href="/doc/eiffelstudio/Record_execution">Record execution</a></li><li><a href="/doc/eiffelstudio/Replay_%28recorded%29_execution">Replay (recorded) execution</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Object_tool">Object tool</a><ul> <li><a href="/doc/eiffelstudio/Attribute_symbols">Attribute symbols</a></li><li><a href="/doc/eiffelstudio/Debug_output">Debug output</a></li><li><a href="/doc/eiffelstudio/Set_slice_size_command">Set slice size command</a></li><li><a href="/doc/eiffelstudio/Object_Viewer_%28also_known_as_Expanded_display%29">Object Viewer (also known as Expanded display)</a></li><li><a href="/doc/eiffelstudio/Remove_object_command">Remove object command</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Expression_evaluation">Expression evaluation</a><ul> <li><a href="/doc/eiffelstudio/Evaluation_tool_or_Watch_tool">Evaluation tool or Watch tool</a></li><li><a href="/doc/eiffelstudio/New_expression_dialog">New expression dialog</a></li></ul></li><li><a href="/doc/eiffelstudio/Debuggee%27s_Object_Storage">Debuggee's Object Storage</a></li><li><a href="/doc/eiffelstudio/Threads_tool">Threads tool</a></li><li><a href="/doc/eiffelstudio/Exceptions_handling_tool">Exceptions handling tool</a></li><li><a href="/doc/eiffelstudio/Stack_overflow_prevention">Stack overflow prevention</a></li><li><a href="/doc/eiffelstudio/Debugging_tips_with_the_objects_grid_view">Debugging tips with the objects grid view</a></li><li><a href="/doc/eiffelstudio/Debugging_preferences">Debugging preferences</a></li><li><a href="/doc/eiffelstudio/Command_line_debugger">Command line debugger</a></li><li><a href="/doc/eiffelstudio/Debugging_limitations">Debugging limitations</a></li></ul></li><li><a href="/doc/eiffelstudio/Error_List_Tool">Error List Tool</a></li><li class="expandable "><a href="/doc/eiffelstudio/Diagram_tool">Diagram tool</a><ul> <li><a href="/doc/eiffelstudio/Notation">Notation</a></li><li><a href="/doc/eiffelstudio/Diagram_toolbar">Diagram toolbar</a></li><li><a href="/doc/eiffelstudio/Views">Views</a></li><li><a href="/doc/eiffelstudio/Contexts">Contexts</a></li><li><a href="/doc/eiffelstudio/Diagram_tool-_Code_generation">Diagram tool: Code generation</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Metrics_tool">Metrics tool</a><ul> <li><a href="/doc/eiffelstudio/Requirements">Requirements</a></li><li class="expandable "><a href="/doc/eiffelstudio/Definitions">Definitions</a><ul> <li><a href="/doc/eiffelstudio/Attributes%2C_metrics_and_measures">Attributes, metrics and measures</a></li><li><a href="/doc/eiffelstudio/Units">Units</a></li><li><a href="/doc/eiffelstudio/Metric_framework_and_theory">Metric framework and theory</a></li><li><a href="/doc/eiffelstudio/Elementary_and_composite_metrics">Elementary and composite metrics</a></li><li><a href="/doc/eiffelstudio/Raw_metrics_and_selection_criteria">Raw metrics and selection criteria</a></li><li><a href="/doc/eiffelstudio/Selection_Criteria">Selection Criteria</a></li><li><a href="/doc/eiffelstudio/Predefined_raw_metrics">Predefined raw metrics</a></li><li><a href="/doc/eiffelstudio/Scopes">Scopes</a></li><li><a href="/doc/eiffelstudio/Domains">Domains</a></li><li><a href="/doc/eiffelstudio/Measurement_archive">Measurement archive</a></li><li><a href="/doc/eiffelstudio/Under_the_Hood_-_How_metrics_work">Under the Hood - How metrics work</a></li><li><a href="/doc/eiffelstudio/Criterion_References">Criterion References</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/User_interface_basics">User interface basics</a><ul> <li><a href="/doc/eiffelstudio/Metric_Evaluation_Panel">Metric Evaluation Panel</a></li><li><a href="/doc/eiffelstudio/Detailed_Result_Panel">Detailed Result Panel</a></li><li><a href="/doc/eiffelstudio/Metric_Definition_Panel">Metric Definition Panel</a></li><li><a href="/doc/eiffelstudio/Metric_History_Panel">Metric History Panel</a></li><li><a href="/doc/eiffelstudio/Metric_Archive_Panel">Metric Archive Panel</a></li></ul></li></ul></li><li><a href="/doc/eiffelstudio/Console_tool">Console tool</a></li><li class="expandable "><a href="/doc/eiffelstudio/Outputs_tool">Outputs tool</a><ul> <li><a href="/doc/eiffelstudio/General_output_pane">General output pane</a></li><li><a href="/doc/eiffelstudio/External_compilation_pane">External compilation pane</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Eiffel_Information_System">Eiffel Information System</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/EIS-_Outgoing">EIS: Outgoing</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Information_Tool">Information Tool</a><ul> <li><a href="/doc/eiffelstudio/Browsing_Information">Browsing Information</a></li><li><a href="/doc/eiffelstudio/Change_Analysis">Change Analysis</a></li><li><a href="/doc/eiffelstudio/Annotation_Management">Annotation Management</a></li><li><a href="/doc/eiffelstudio/Protocols">Protocols</a></li><li><a href="/doc/eiffelstudio/Variable_Definition">Variable Definition</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EIS-_Incoming">EIS: Incoming</a><ul> <li><a href="/doc/eiffelstudio/Eiffel_Scheme_Syntax">Eiffel Scheme Syntax</a></li><li><a href="/doc/eiffelstudio/EIS_incoming_Examples">EIS incoming Examples</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/AutoTest">AutoTest</a><ul> <li><a href="/doc/eiffelstudio/The_AutoTest_Interface">The AutoTest Interface</a></li><li><a href="/doc/eiffelstudio/The_Eiffel_Test_Wizard">The Eiffel Test Wizard</a></li></ul></li><li><a href="/doc/eiffelstudio/Source_Control_Management">Source Control</a></li><li class="expandable "><a href="/doc/eiffelstudio/Wizards_and_dialogs">Wizards and dialogs</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Profiler_Wizard">Profiler Wizard</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Profiler_wizard_guided_tour">Profiler wizard guided tour</a><ul> <li><a href="/doc/eiffelstudio/Select_the_Compilation_mode">Select the Compilation mode</a></li><li><a href="/doc/eiffelstudio/Reuse_or_Generate_an_Execution_Profile">Reuse or Generate an Execution Profile</a></li><li><a href="/doc/eiffelstudio/Select_a_Run-time_information_record_to_generate_the_Execution_Profile">Select a Run-time information record to generate the Execution Profile</a></li><li><a href="/doc/eiffelstudio/Select_the_information_you_need_and_formulate_your_query">Select the information you need and formulate your query</a></li><li><a href="/doc/eiffelstudio/Profile_query_window">Profile query window</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Profiler_How_To%27s">Profiler How To's</a><ul> <li><a href="/doc/eiffelstudio/How_to_set_up_a_Profiler_Configuration_File">How to set up a Profiler Configuration File</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Dialogs">Dialogs</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/New_feature_dialog">New feature dialog</a><ul> <li><a href="/doc/eiffelstudio/New_feature_dialog_overview">New feature dialog overview</a></li><li><a href="/doc/eiffelstudio/New_procedure_layout">New procedure layout</a></li><li><a href="/doc/eiffelstudio/New_function_layout">New function layout</a></li><li><a href="/doc/eiffelstudio/New_attribute_layout">New attribute layout</a></li><li class="expandable "><a href="/doc/eiffelstudio/New_feature_dialog-_feature_properties_modification">New feature dialog: feature properties modification</a><ul> <li><a href="/doc/eiffelstudio/Feature_clauses">Feature clauses</a></li><li><a href="/doc/eiffelstudio/Name_field">Name field</a></li><li><a href="/doc/eiffelstudio/Argument_list">Argument list</a></li><li><a href="/doc/eiffelstudio/Header_comment">Header comment</a></li><li><a href="/doc/eiffelstudio/Precondition">Precondition</a></li><li><a href="/doc/eiffelstudio/Local_variable">Local variable</a></li><li><a href="/doc/eiffelstudio/Feature_body">Feature body</a></li><li><a href="/doc/eiffelstudio/Postcondition">Postcondition</a></li><li><a href="/doc/eiffelstudio/Type_selection">Type selection</a></li><li><a href="/doc/eiffelstudio/Invariant_field">Invariant field</a></li><li><a href="/doc/eiffelstudio/Set-procedure">Set-procedure</a></li></ul></li></ul></li><li><a href="/doc/eiffelstudio/Error_wizard">Error wizard</a></li><li><a href="/doc/eiffelstudio/External_commands_editor_dialog">External commands editor dialog</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_Preferences">EiffelStudio Preferences</a><ul> <li><a href="/doc/eiffelstudio/Preference_window_overview">Preference window overview</a></li><li class="expandable "><a href="/doc/eiffelstudio/Preferences_Reference">Preferences Reference</a><ul> <li><a href="/doc/eiffelstudio/General_Preferences">General Preferences</a></li><li class="expandable "><a href="/doc/eiffelstudio/Interface">Interface</a><ul> <li><a href="/doc/eiffelstudio/Development_Window_Preferences">Development Window Preferences</a></li><li><a href="/doc/eiffelstudio/Discardable_dialogs">Discardable dialogs</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_Tools_Preferences">EiffelStudio Tools Preferences</a><ul> <li><a href="/doc/eiffelstudio/Context_Tools">Context Tools</a></li><li><a href="/doc/eiffelstudio/EiffelStudio_Diagram_Tool_Preferences">EiffelStudio Diagram Tool Preferences</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Editor_Preferences">Editor Preferences</a><ul> <li><a href="/doc/eiffelstudio/General_Editor_Preferences">General Editor Preferences</a></li><li class="expandable "><a href="/doc/eiffelstudio/Eiffel_Editor_Preferences">Eiffel Editor Preferences</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Syntax_automatic_completion_preferences">Syntax automatic completion preferences</a><ul> <li><a href="/doc/eiffelstudio/Keywords_automatic_completion_preferences">Keywords automatic completion preferences</a></li><li><a href="/doc/eiffelstudio/Keyword_completion_customization">Keyword completion customization</a></li><li><a href="/doc/eiffelstudio/Default_values_for_keyword_completion_preferences">Default values for keyword completion preferences</a></li></ul></li></ul></li><li><a href="/doc/eiffelstudio/Keyboard_shortcuts_preferences">Keyboard shortcuts preferences</a></li></ul></li><li><a href="/doc/eiffelstudio/Debugger_Preferences">Debugger Preferences</a></li><li><a href="/doc/eiffelstudio/Recent_Project_Preferences">Recent Project Preferences</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Formatted_information_about_compiled_classes_and_features">Formatted information about compiled classes and features</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Class_views">Class views</a><ul> <li><a href="/doc/eiffelstudio/Class_formatters-_Basic_text_view">Class formatters: Basic text view</a></li><li><a href="/doc/eiffelstudio/Clickable_view">Clickable view</a></li><li><a href="/doc/eiffelstudio/Class_formatters-_Flat_view">Class formatters: Flat view</a></li><li><a href="/doc/eiffelstudio/Contract_view">Contract view</a></li><li><a href="/doc/eiffelstudio/Flat_Contract_view">Flat Contract view</a></li><li><a href="/doc/eiffelstudio/Ancestors">Ancestors</a></li><li><a href="/doc/eiffelstudio/Descendants">Descendants</a></li><li><a href="/doc/eiffelstudio/Clients">Clients</a></li><li><a href="/doc/eiffelstudio/Suppliers">Suppliers</a></li><li><a href="/doc/eiffelstudio/Attributes">Attributes</a></li><li><a href="/doc/eiffelstudio/Routines">Routines</a></li><li><a href="/doc/eiffelstudio/Invariants">Invariants</a></li><li><a href="/doc/eiffelstudio/Creators">Creators</a></li><li><a href="/doc/eiffelstudio/Deferred_features">Deferred features</a></li><li><a href="/doc/eiffelstudio/Once_routines_and_constants">Once routines and constants</a></li><li><a href="/doc/eiffelstudio/Class_formatters-_External_features">Class formatters: External features</a></li><li><a href="/doc/eiffelstudio/Exported_features">Exported features</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Feature_views">Feature views</a><ul> <li><a href="/doc/eiffelstudio/Feature_formatters-_Basic_text_view">Feature formatters: Basic text view</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Flat_view">Feature formatters: Flat view</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Callers">Feature formatters: Callers</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Assigners">Feature formatters: Assigners</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Creators">Feature formatters: Creators</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Callees">Feature formatters: Callees</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Assignees">Feature formatters: Assignees</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Creations">Feature formatters: Creations</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Implementers">Feature formatters: Implementers</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Ancestor_versions">Feature formatters: Ancestor versions</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Descendant_versions">Feature formatters: Descendant versions</a></li><li><a href="/doc/eiffelstudio/Feature_formatters-_Homonyms">Feature formatters: Homonyms</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio_How_To%27s">EiffelStudio How To's</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/EiffelStudio-_Starting_a_project">EiffelStudio: Starting a project</a><ul> <li><a href="/doc/eiffelstudio/EiffelStudio-_Creating_a_new_project">EiffelStudio: Creating a new project</a></li><li><a href="/doc/eiffelstudio/Retrieving_a_project_from_a_configuration_file">Retrieving a project from a configuration file</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Browsing">Browsing</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Searching">Searching</a><ul> <li><a href="/doc/eiffelstudio/Looking_for_a_cluster">Looking for a cluster</a></li><li><a href="/doc/eiffelstudio/Looking_for_a_class">Looking for a class</a></li><li><a href="/doc/eiffelstudio/Looking_for_a_feature">Looking for a feature</a></li><li><a href="/doc/eiffelstudio/Looking_for_an_expression_in_text">Looking for an expression in text</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Viewing_information_about_a_component">Viewing information about a component</a><ul> <li><a href="/doc/eiffelstudio/Centering_tools_on_a_component">Centering tools on a component</a></li><li><a href="/doc/eiffelstudio/Viewing_information_about_a_cluster">Viewing information about a cluster</a></li><li><a href="/doc/eiffelstudio/Viewing_information_about_a_class">Viewing information about a class</a></li><li><a href="/doc/eiffelstudio/Viewing_information_about_a_feature">Viewing information about a feature</a></li></ul></li><li><a href="/doc/eiffelstudio/Opening_new_windows">Opening new windows</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Editing_a_project">Editing a project</a><ul> <li><a href="/doc/eiffelstudio/Adding_a_cluster">Adding a cluster</a></li><li><a href="/doc/eiffelstudio/Adding_a_library">Adding a library</a></li><li><a href="/doc/eiffelstudio/Adding_a_class">Adding a class</a></li><li class="expandable "><a href="/doc/eiffelstudio/Adding_a_feature">Adding a feature</a><ul> <li><a href="/doc/eiffelstudio/Opening_the_new_feature_dialog">Opening the new feature dialog</a></li><li><a href="/doc/eiffelstudio/Adding_a_procedure">Adding a procedure</a></li><li><a href="/doc/eiffelstudio/Adding_a_function">Adding a function</a></li><li><a href="/doc/eiffelstudio/Adding_an_attribute">Adding an attribute</a></li></ul></li><li><a href="/doc/eiffelstudio/Removing_a_cluster">Removing a cluster</a></li><li><a href="/doc/eiffelstudio/Removing_a_class">Removing a class</a></li><li><a href="/doc/eiffelstudio/Removing_a_feature">Removing a feature</a></li><li><a href="/doc/eiffelstudio/Moving_a_class">Moving a class</a></li><li><a href="/doc/eiffelstudio/Changing_project_parameters">Changing project parameters</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Compiling">Compiling</a><ul> <li><a href="/doc/eiffelstudio/Generating_executables">Generating executables</a></li><li><a href="/doc/eiffelstudio/Generating_libraries">Generating libraries</a></li><li><a href="/doc/eiffelstudio/Setting_the_assertion_level">Setting the assertion level</a></li><li><a href="/doc/eiffelstudio/Setting_the_syntax_variant">Setting the syntax variant</a></li><li><a href="/doc/eiffelstudio/Enabling_the_profiler">Enabling the profiler</a></li><li><a href="/doc/eiffelstudio/Using_libraries">Using libraries</a></li><li><a href="/doc/eiffelstudio/Tuning_a_program">Tuning a program</a></li><li><a href="/doc/eiffelstudio/Using_threads">Using threads</a></li><li><a href="/doc/eiffelstudio/Clean_compile">Clean compile</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Running_and_debugging">Running and debugging</a><ul> <li><a href="/doc/eiffelstudio/Running_an_application">Running an application</a></li><li><a href="/doc/eiffelstudio/Interrupting_an_application">Interrupting an application</a></li><li><a href="/doc/eiffelstudio/Exploring_an_application_dynamic_state">Exploring an application dynamic state</a></li><li><a href="/doc/eiffelstudio/Using_breakpoints">Using breakpoints</a></li><li><a href="/doc/eiffelstudio/Handling_exceptions">Handling exceptions</a></li><li><a href="/doc/eiffelstudio/Using_debug_clauses">Using debug clauses</a></li><li><a href="/doc/eiffelstudio/Setting_the_command_line_arguments">Setting the command line arguments</a></li><li><a href="/doc/eiffelstudio/Profiling">Profiling</a></li><li><a href="/doc/eiffelstudio/Tracing">Tracing</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Designing_a_project">Designing a project</a><ul> <li><a href="/doc/eiffelstudio/Switching_to_the_diagram_tool">Switching to the diagram tool</a></li><li><a href="/doc/eiffelstudio/Undoing_and_redoing">Undoing and redoing</a></li><li class="expandable "><a href="/doc/eiffelstudio/Altering_the_system">Altering the system</a><ul> <li><a href="/doc/eiffelstudio/Creating_a_new_class">Creating a new class</a></li><li><a href="/doc/eiffelstudio/Creating_a_new_feature">Creating a new feature</a></li><li class="expandable "><a href="/doc/eiffelstudio/Refactoring">Refactoring</a><ul> <li><a href="/doc/eiffelstudio/Rename_Class">Rename Class</a></li><li><a href="/doc/eiffelstudio/Rename_Feature">Rename Feature</a></li><li><a href="/doc/eiffelstudio/Pull_up_Feature">Pull up Feature</a></li></ul></li><li><a href="/doc/eiffelstudio/Deleting_items">Deleting items</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Managing_links">Managing links</a><ul> <li><a href="/doc/eiffelstudio/Creating_inheritance_links">Creating inheritance links</a></li><li><a href="/doc/eiffelstudio/Creating_client-supplier_links">Creating client-supplier links</a></li><li><a href="/doc/eiffelstudio/Creating_aggregate_client-supplier_links">Creating aggregate client-supplier links</a></li><li><a href="/doc/eiffelstudio/Using_the_link_tool">Using the link tool</a></li><li><a href="/doc/eiffelstudio/Creating_handles">Creating handles</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Modifying_the_display">Modifying the display</a><ul> <li><a href="/doc/eiffelstudio/Showing_or_hiding_links_and_labels">Showing or hiding links and labels</a></li><li><a href="/doc/eiffelstudio/Changing_system_exploration_depth">Changing system exploration depth</a></li><li><a href="/doc/eiffelstudio/Removing_items_from_a_view">Removing items from a view</a></li><li><a href="/doc/eiffelstudio/Changing_colors_of_classes">Changing colors of classes</a></li><li><a href="/doc/eiffelstudio/Zooming_a_diagram">Zooming a diagram</a></li><li><a href="/doc/eiffelstudio/Retrieving_all_classes_into_a_cluster">Retrieving all classes into a cluster</a></li><li><a href="/doc/eiffelstudio/Iconifying_and_restoring_a_cluster">Iconifying and restoring a cluster</a></li><li><a href="/doc/eiffelstudio/Change_the_Display_Quality">Change the Display Quality</a></li><li><a href="/doc/eiffelstudio/Turn_on_Physics_Mode">Turn on Physics Mode</a></li><li><a href="/doc/eiffelstudio/Switching_between_BON_and_UML_View">Switching between BON and UML View</a></li><li><a href="/doc/eiffelstudio/Anchoring">Anchoring</a></li><li><a href="/doc/eiffelstudio/Adjusting_Physics_Settings">Adjusting Physics Settings</a></li><li><a href="/doc/eiffelstudio/Using_the_Cluster_Legend">Using the Cluster Legend</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Managing_views">Managing views</a><ul> <li><a href="/doc/eiffelstudio/Adding_a_view">Adding a view</a></li><li><a href="/doc/eiffelstudio/Deleting_a_view">Deleting a view</a></li></ul></li><li><a href="/doc/eiffelstudio/Exporting_a_diagram_to_PNG_image_file">Exporting a diagram to PNG image file</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/How_to_analyze_a_project">How to analyze a project</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Computing_a_measure">Computing a measure</a><ul> <li><a href="/doc/eiffelstudio/Evaluating_a_measure">Evaluating a measure</a></li><li><a href="/doc/eiffelstudio/Saving_a_measure">Saving a measure</a></li><li><a href="/doc/eiffelstudio/Viewing_measure_details">Viewing measure details</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Handling_new_metrics">Handling new metrics</a><ul> <li class="expandable "><a href="/doc/eiffelstudio/Defining_new_metrics">Defining new metrics</a><ul> <li><a href="/doc/eiffelstudio/Defining_derived_metrics">Defining derived metrics</a></li><li><a href="/doc/eiffelstudio/Defining_linear_metrics">Defining linear metrics</a></li><li><a href="/doc/eiffelstudio/Defining_ratio_metrics">Defining ratio metrics</a></li></ul></li><li><a href="/doc/eiffelstudio/Managing_new_metrics">Managing new metrics</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Handling_archives">Handling archives</a><ul> <li><a href="/doc/eiffelstudio/Creating_an_archive">Creating an archive</a></li><li><a href="/doc/eiffelstudio/Comparing_to_an_archive">Comparing to an archive</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Generating_documentation">Generating documentation</a><ul> <li><a href="/doc/eiffelstudio/Generating_multi-format_documentation">Generating multi-format documentation</a></li><li><a href="/doc/eiffelstudio/Generating_XMI_documentation">Generating XMI documentation</a></li></ul></li><li class="expandable "><a href="/doc/eiffelstudio/Customizing_EiffelStudio">Customizing EiffelStudio</a><ul> <li><a href="/doc/eiffelstudio/Setting_the_editor_behavior">Setting the editor behavior</a></li><li><a href="/doc/eiffelstudio/Changing_texts_display">Changing texts display</a></li><li><a href="/doc/eiffelstudio/Customizing_toolbars">Customizing toolbars</a></li><li><a href="/doc/eiffelstudio/Making_the_context_tool_independent_from_the_editor">Making the context tool independent from the editor</a></li><li><a href="/doc/eiffelstudio/Changing_the_default_history_size">Changing the default history size</a></li><li><a href="/doc/eiffelstudio/Choosing_classes_to_be_ignored_in_BON_diagrams">Choosing classes to be ignored in BON diagrams</a></li><li><a href="/doc/eiffelstudio/Customizing_class_text_views">Customizing class text views</a></li><li><a href="/doc/eiffelstudio/Configuring_an_external_editor">Configuring an external editor</a></li><li><a href="/doc/eiffelstudio/Customizing_EiffelStudio_for_Subversion_commands">Customizing EiffelStudio for Subversion commands</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Solutions_and_Libraries">Solutions and Libraries</a><ul> <li><a href="/doc/solutions/IRON-_Eiffel_package_repository">IRON Eiffel repository</a></li><li class="expandable "><a href="/doc/solutions/.NET">.NET</a><ul> <li><a href="/doc/solutions/.NET_Installation_instructions">.NET Installation instructions</a></li><li><a href="/doc/solutions/Building_a_.NET_application">Building a .NET application</a></li><li class="expandable "><a href="/doc/solutions/The_Eiffel_for_.NET_language">The Eiffel for .NET language</a><ul> <li class="expandable "><a href="/doc/solutions/Conventions">Conventions</a><ul> <li><a href="/doc/solutions/Eiffel_for_.NET_Terminology">Eiffel for .NET Terminology</a></li><li><a href="/doc/solutions/Eiffel_Class_and_Feature_Names">Eiffel Class and Feature Names</a></li><li><a href="/doc/solutions/Type_Organization">Type Organization</a></li><li><a href="/doc/solutions/Constructors_and_Creation_Procedures">Constructors and Creation Procedures</a></li><li><a href="/doc/solutions/Similar_Types_Occurring_in_Both_Libraries">Similar Types Occurring in Both Libraries</a></li><li><a href="/doc/solutions/Eiffel_reserved_words">Eiffel reserved words</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Eiffel_for_.NET">Eiffel for .NET</a><ul> <li><a href="/doc/solutions/Eiffel_Classes">Eiffel Classes</a></li><li><a href="/doc/solutions/Adding_Class_Features">Adding Class Features</a></li><li><a href="/doc/solutions/Inheritance">Inheritance</a></li><li><a href="/doc/solutions/Genericity">Genericity</a></li><li><a href="/doc/solutions/Design_by_Contract_and_Assertions">Design by Contract and Assertions</a></li><li><a href="/doc/solutions/Exception_Mechanism">Exception Mechanism</a></li><li><a href="/doc/solutions/Event_Programming_with_Agents">Event Programming with Agents</a></li><li><a href="/doc/solutions/Using_Referenced_Assemblies">Using Referenced Assemblies</a></li><li><a href="/doc/solutions/Eiffel_for_.NET_Compliance">Eiffel for .NET Compliance</a></li><li><a href="/doc/solutions/Referenced_Assembly_Type_and_Feature_Name_Conversion">Referenced Assembly Type and Feature Name Conversion</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Eiffel_for_.NET_Integration">Eiffel for .NET Integration</a><ul> <li><a href="/doc/solutions/Workaround_Eiffel_.NET_limitations">Workarounds</a></li><li><a href="/doc/solutions/Eiffel_.NETCore_execution">NETCore execution</a></li></ul></li><li><a href="/doc/solutions/Known_issues">Known issues</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Eiffel_.NET_samples">Eiffel .NET samples</a><ul> <li class="expandable "><a href="/doc/solutions/ADO_.NET_Samples">ADO .NET Samples</a><ul> <li><a href="/doc/solutions/ADO.NET_Sample">ADO.NET Sample</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Console_Samples">Console Samples</a><ul> <li><a href="/doc/solutions/Calculator-_console">Calculator: console</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Threads_Samples">Threads Samples</a><ul> <li><a href="/doc/solutions/Pools">Pools</a></li><li><a href="/doc/solutions/Timers">Timers</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Winform_Samples">Winform Samples</a><ul> <li><a href="/doc/solutions/Simple_Hello_world_form_sample">Simple Hello world form sample</a></li><li><a href="/doc/solutions/Message_Box">Message Box</a></li><li class="expandable "><a href="/doc/solutions/Menus">Menus</a><ul> <li><a href="/doc/solutions/Menu_Details">Menu Details</a></li></ul></li><li class="expandable "><a href="/doc/solutions/MDI">MDI</a><ul> <li><a href="/doc/solutions/MDI_Details">MDI Details</a></li></ul></li><li><a href="/doc/solutions/Calculator-_winform">Calculator: winform</a></li><li><a href="/doc/solutions/GDI_plus_-_text">GDI plus - text</a></li><li><a href="/doc/solutions/Date_Time_Picker">Date Time Picker</a></li><li><a href="/doc/solutions/Progress_bar_sample">Progress bar sample</a></li><li><a href="/doc/solutions/Simple_data_binding">Simple data binding</a></li><li><a href="/doc/solutions/Tree_view">Tree view</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Eiffel_for_ASP.NET_Documentation">Eiffel for ASP.NET Documentation</a><ul> <li class="expandable "><a href="/doc/solutions/Writing_ASP.NET_pages_in_Eiffel">Writing ASP.NET pages in Eiffel</a><ul> <li><a href="/doc/solutions/Eiffel_for_ASP.NET_Installation">Eiffel for ASP.NET Installation</a></li><li><a href="/doc/solutions/CodeDom-_Getting_Started">CodeDom: Getting Started</a></li><li><a href="/doc/solutions/Using_Eiffel_%28to_write_ASP.NET_pages%29">Using Eiffel (to write ASP.NET pages)</a></li><li><a href="/doc/solutions/Names_Mappings">Names Mappings</a></li></ul></li><li class="expandable "><a href="/doc/solutions/The_Eiffel_CodeDom_Provider">The Eiffel CodeDom Provider</a><ul> <li><a href="/doc/solutions/About_the_Code_Document_Object_Model_%28CodeDom%29">About the Code Document Object Model (CodeDom)</a></li><li><a href="/doc/solutions/Installation">Installation</a></li><li><a href="/doc/solutions/Supported_Constructs">Supported Constructs</a></li><li><a href="/doc/solutions/Configuration">Configuration</a></li><li><a href="/doc/solutions/Logging">Logging</a></li><li><a href="/doc/solutions/Required_Permissions">Required Permissions</a></li><li><a href="/doc/solutions/Common_Scenarios">Common Scenarios</a></li><li><a href="/doc/solutions/Eiffel_Implementation">Eiffel Implementation</a></li><li><a href="/doc/solutions/Limitations">Limitations</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Eiffel_for_ASP.NET_Tools_and_Administration">Eiffel for ASP.NET Tools and Administration</a><ul> <li><a href="/doc/solutions/Eiffel_CodeDom_Provider_Manager">Eiffel CodeDom Provider Manager</a></li><li><a href="/doc/solutions/eSplitter">eSplitter</a></li><li><a href="/doc/solutions/Name_Mapper">Name Mapper</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Basic_computing">Basic computing</a><ul> <li><a href="/doc/solutions/Process_and_BaseProcess">External processes</a></li><li class="expandable "><a href="/doc/solutions/EiffelBase">EiffelBase</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelBase_Tutorial">EiffelBase Tutorial</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelBase%2C_The_Kernel">EiffelBase, The Kernel</a><ul> <li><a href="/doc/solutions/Universal_class_and_its_features">Universal class and its features</a></li><li><a href="/doc/solutions/Language-related_facilities">Language-related facilities</a></li><li><a href="/doc/solutions/Files%2C_input%2C_output">Files, input, output</a></li><li><a href="/doc/solutions/Persistence%2C_storage%2C_and_retrieval">Persistence, storage, and retrieval</a></li><li><a href="/doc/solutions/Access_to_internal_properties">Access to internal properties</a></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelBase_Data_Structures_Overview">EiffelBase Data Structures Overview</a><ul> <li><a href="/doc/solutions/EiffelBase%2C_Abstract_Container_Structures-_The_Taxonomy">EiffelBase, Abstract Container Structures: The Taxonomy</a></li><li><a href="/doc/solutions/EiffelBase_Data_Structures%2C_Lists">EiffelBase Data Structures, Lists</a></li><li><a href="/doc/solutions/EiffelBase%2C_Dispensers">EiffelBase, Dispensers</a></li><li><a href="/doc/solutions/EiffelBase%2C_Trees">EiffelBase, Trees</a></li><li><a href="/doc/solutions/EiffelBase%2C_Sets">EiffelBase, Sets</a></li><li><a href="/doc/solutions/EiffelBase%2C_Tables">EiffelBase, Tables</a></li><li><a href="/doc/solutions/EiffelBase%2C_Iteration">EiffelBase, Iteration</a></li></ul></li><li><a href="/doc/solutions/EiffelBase_Support_Cluster">EiffelBase Support Cluster</a></li></ul></li><li><a href="/doc/solutions/EiffelBase_Class_Reference">EiffelBase Class Reference</a></li><li class="expandable "><a href="/doc/solutions/EiffelBase_Samples">EiffelBase Samples</a><ul> <li><a href="/doc/solutions/EiffelBase_Sample-_Calculator">EiffelBase Sample: Calculator</a></li></ul></li><li><a href="/doc/solutions/Eiffel_Software_Free_Eiffel_Library_License_%28IFELL%29">Free Eiffel Library License</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Graphics">Graphics</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelBuild">EiffelBuild</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelBuild_How_To%27s">EiffelBuild How To's</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelBuild-_Starting_a_project">EiffelBuild: Starting a project</a><ul> <li><a href="/doc/solutions/EiffelBuild-_Creating_a_new_project">EiffelBuild: Creating a new project</a></li><li><a href="/doc/solutions/Retrieving_a_project_from_a_Build_project_file">Retrieving a project from a Build project file</a></li></ul></li><li><a href="/doc/solutions/Create_an_object">Create an object</a></li><li><a href="/doc/solutions/Delete_an_object">Delete an object</a></li><li><a href="/doc/solutions/Save_a_project">Save a project</a></li><li><a href="/doc/solutions/Reparent_an_Object">Reparent an Object</a></li><li><a href="/doc/solutions/Import_a_project">Import a project</a></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelBuild_Reference">EiffelBuild Reference</a><ul> <li><a href="/doc/solutions/EiffelBuild_Notation">EiffelBuild Notation</a></li><li class="expandable "><a href="/doc/solutions/EiffelBuild-_General_interface_description">EiffelBuild: General interface description</a><ul> <li><a href="/doc/solutions/EiffelBuild_window_overview">EiffelBuild window overview</a></li><li><a href="/doc/solutions/Main_toolbar">Main toolbar</a></li><li><a href="/doc/solutions/EiffelBuild-_Key_shortcuts">EiffelBuild: Key shortcuts</a></li><li><a href="/doc/solutions/Docking">Docking</a></li></ul></li><li><a href="/doc/solutions/Layout_constructor">Layout constructor</a></li><li><a href="/doc/solutions/Type_selector">Type selector</a></li><li class="expandable "><a href="/doc/solutions/Object_editor">Object editor</a><ul> <li><a href="/doc/solutions/Merging_radio_button_groups">Merging radio button groups</a></li><li><a href="/doc/solutions/Positioning_table_children">Positioning table children</a></li><li><a href="/doc/solutions/Positioning_fixed_children">Positioning fixed children</a></li></ul></li><li><a href="/doc/solutions/Display_window">Display window</a></li><li><a href="/doc/solutions/Builder_window">Builder window</a></li><li><a href="/doc/solutions/Component_selector">Component selector</a></li><li><a href="/doc/solutions/Widget_selector">Widget selector</a></li><li><a href="/doc/solutions/Component_viewer">Component viewer</a></li><li><a href="/doc/solutions/History">History</a></li><li><a href="/doc/solutions/Constants">Constants</a></li><li class="expandable "><a href="/doc/solutions/EiffelBuild-_Project_settings_window">EiffelBuild: Project settings window</a><ul> <li><a href="/doc/solutions/Build_Tab">Build Tab</a></li><li><a href="/doc/solutions/Generation_Tab">Generation Tab</a></li></ul></li><li><a href="/doc/solutions/EiffelBuild_Preferences">EiffelBuild Preferences</a></li><li><a href="/doc/solutions/EiffelBuild-_Code_Generation">EiffelBuild: Code Generation</a></li></ul></li><li><a href="/doc/solutions/EiffelBuild_Version_History">EiffelBuild Version History</a></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelVision_2">EiffelVision 2</a><ul> <li><a href="/doc/solutions/EiffelVision_Introduction">EiffelVision Introduction</a></li><li class="expandable "><a href="/doc/solutions/Vison2_-_How-to">How to ...</a><ul> <li><a href="/doc/solutions/How_to_build_a_concurrent_graphical_application-_EiffelVision_with_SCOOP">How to build a concurrent graphical application: EiffelVision with SCOOP</a></li><li><a href="/doc/solutions/Triggering_Pick-and-Drop">Triggering PnD</a></li><li><a href="/doc/solutions/Converting_EiffelVision_2_Systems_to_Void-Safety">Converting EiffelVision 2 Systems to Void-Safety</a></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelVision_Library_Reference_Manual">EiffelVision Library Reference Manual</a><ul> <li><a href="/doc/solutions/Kernel">Kernel</a></li><li class="expandable "><a href="/doc/solutions/Widgets">Widgets</a><ul> <li><a href="/doc/solutions/Primitives">Primitives</a></li><li><a href="/doc/solutions/Containers">Containers</a></li><li><a href="/doc/solutions/EiffelVision_Dialogs">EiffelVision Dialogs</a></li></ul></li><li><a href="/doc/solutions/Items">Items</a></li><li><a href="/doc/solutions/Events">Events</a></li><li class="expandable "><a href="/doc/solutions/Properties">Properties</a><ul> <li><a href="/doc/solutions/EiffelVision_Pick_and_Drop">EiffelVision Pick and Drop</a></li></ul></li><li><a href="/doc/solutions/Support">Support</a></li><li><a href="/doc/solutions/Figures">Figures</a></li></ul></li><li><a href="/doc/solutions/EiffelVision_2_Class_Reference">EiffelVision 2 Class Reference</a></li><li class="expandable "><a href="/doc/solutions/EiffelVision_2_Samples">EiffelVision 2 Samples</a><ul> <li><a href="/doc/solutions/Widgets_Sample">Widgets Sample</a></li><li><a href="/doc/solutions/Accelerator_Sample">Accelerator Sample</a></li><li><a href="/doc/solutions/Cursor_Sample">Cursor Sample</a></li><li><a href="/doc/solutions/Gauges_Sample">Gauges Sample</a></li><li><a href="/doc/solutions/Standard_dialogs_Sample">Standard_dialogs Sample</a></li><li><a href="/doc/solutions/Viewport_Sample">Viewport Sample</a></li></ul></li><li><a href="/doc/solutions/Revisions_and_Bug_Fixes">Revisions and Bug Fixes</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Dates_and_times">Dates and times</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelTime">EiffelTime</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelTime_Tutorial">EiffelTime Tutorial</a><ul> <li><a href="/doc/solutions/Absolute_time">Absolute time</a></li><li><a href="/doc/solutions/Duration">Duration</a></li><li><a href="/doc/solutions/Interval">Interval</a></li><li><a href="/doc/solutions/DATE_TIME_to_STRING_Conversion">DATE TIME to STRING Conversion</a></li><li><a href="/doc/solutions/More_precision">More precision</a></li></ul></li><li><a href="/doc/solutions/EiffelTime_Class_Reference">EiffelTime Class Reference</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Including_other_languages">With other languages</a><ul> <li class="expandable "><a href="/doc/solutions/Eiffel_%22external%22_mechanism">Eiffel "external" mechanism</a><ul> <li><a href="/doc/solutions/Interfacing_with_C_and_C%2B%2B">Interfacing with C and C++</a></li><li><a href="/doc/solutions/Interfacing_with_DLLs">Interfacing with DLLs</a></li><li class="expandable "><a href="/doc/solutions/Obsolete_%22external%22_interfaces">Obsolete "external" interfaces</a><ul> <li><a href="/doc/solutions/C_externals">C externals</a></li><li><a href="/doc/solutions/C%2B%2B_Externals">C++ Externals</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/CECIL">CECIL</a><ul> <li><a href="/doc/solutions/Compiling_an_Eiffel_system_for_CECIL">Compiling an Eiffel system for CECIL</a></li><li><a href="/doc/solutions/Using_a_CECIL_archive">Using a CECIL archive</a></li><li><a href="/doc/solutions/CECIL_interface_overview">CECIL interface overview</a></li><li class="expandable "><a href="/doc/solutions/CECIL_Reference">CECIL Reference</a><ul> <li><a href="/doc/solutions/attribute_exists">attribute_exists</a></li><li><a href="/doc/solutions/eif_access">eif_access</a></li><li><a href="/doc/solutions/eif_adopt">eif_adopt</a></li><li><a href="/doc/solutions/eif_attribute">eif_attribute</a></li><li><a href="/doc/solutions/eif_attribute_type">eif_attribute_type</a></li><li><a href="/doc/solutions/eif_create">eif_create</a></li><li><a href="/doc/solutions/eif_disable_visible_exception">eif_disable_visible_exception</a></li><li><a href="/doc/solutions/eif_enable_visible_exception">eif_enable_visible_exception</a></li><li><a href="/doc/solutions/eif_name">eif_name</a></li><li><a href="/doc/solutions/eif_name_by_tid">eif_name_by_tid</a></li><li><a href="/doc/solutions/eif_procedure">eif_procedure</a></li><li><a href="/doc/solutions/eif_protect">eif_protect</a></li><li><a href="/doc/solutions/eif_string">eif_string</a></li><li><a href="/doc/solutions/eif_type">eif_type</a></li><li><a href="/doc/solutions/eif_type_by_name">eif_type_by_name</a></li><li><a href="/doc/solutions/eif_type_by_reference">eif_type_by_reference</a></li><li><a href="/doc/solutions/eif_type_id">eif_type_id</a></li><li><a href="/doc/solutions/eif_wean">eif_wean</a></li><li><a href="/doc/solutions/eif_%2A_function">eif_*_function</a></li></ul></li><li class="expandable "><a href="/doc/solutions/CECIL_samples">CECIL samples</a><ul> <li><a href="/doc/solutions/CECIL_-_C_to_Eiffel">CECIL - C to Eiffel</a></li><li><a href="/doc/solutions/CECIL_-_Eiffel_to_C">CECIL - Eiffel to C</a></li><li><a href="/doc/solutions/CECIL_-_Basic_sample">CECIL - Basic sample</a></li><li><a href="/doc/solutions/CECIL_-_Threads">CECIL - Threads</a></li><li><a href="/doc/solutions/CECIL_-_How_to_compile_the_samples%3F">CECIL - How to compile the samples?</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Eiffel2Java">Eiffel2Java</a><ul> <li><a href="/doc/solutions/Eiffel2Java_Tutorial">Eiffel2Java Tutorial</a></li><li><a href="/doc/solutions/Eiffel2Java_class_reference">Eiffel2Java class reference</a></li><li><a href="/doc/solutions/Eiffel2Java_Sample">Eiffel2Java Sample</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Porting_instructions">Porting instructions</a><ul> <li><a href="/doc/solutions/Porting_an_Eiffel_application_from_UNIX_to_Windows_or_vice-versa">Porting an Eiffel application from UNIX to Windows or vice-versa</a></li></ul></li><li class="expandable "><a href="/doc/solutions/Concurrency">Concurrency</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelThreads">EiffelThreads</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelThread_Tutorial">EiffelThread Tutorial</a><ul> <li><a href="/doc/solutions/Thread_library_overview">Thread library overview</a></li><li><a href="/doc/solutions/Compilation_of_multithreaded_systems">Compilation of multithreaded systems</a></li><li><a href="/doc/solutions/Once_features_in_multithreaded_mode">Once features in multithreaded mode</a></li><li><a href="/doc/solutions/Multithread_FAQ">Multithread FAQ</a></li></ul></li><li><a href="/doc/solutions/EiffelThread_Class_Reference">EiffelThread Class Reference</a></li></ul></li><li><a href="/doc/solutions/SCOOP_tutorial">SCOOP Tutorial (hands-on): a small concurrent email system</a></li><li class="expandable "><a href="/doc/solutions/Concurrent_programming_with_SCOOP">SCOOP</a><ul> <li><a href="/doc/solutions/Getting_Started_with_SCOOP">Getting Started</a></li><li><a href="/doc/solutions/Regions_and_Processors">Regions and Processors</a></li><li><a href="/doc/solutions/Separate_Calls">Separate Calls</a></li><li><a href="/doc/solutions/Exclusive_Access">Exclusive Access</a></li><li><a href="/doc/solutions/Design_by_Contract_in_SCOOP">Design by Contract</a></li><li><a href="/doc/solutions/Asynchronous_Calls">Asynchronous Calls</a></li><li><a href="/doc/solutions/Exceptions_in_SCOOP">Exceptions</a></li><li class="expandable "><a href="/doc/solutions/SCOOP_examples">SCOOP examples</a><ul> <li><a href="/doc/solutions/Single-element_producer-consumer">Single-element producer-consumer</a></li><li><a href="/doc/solutions/Counter">Counter</a></li><li><a href="/doc/solutions/Producer-consumer">Producer-consumer</a></li><li><a href="/doc/solutions/Dining_philosophers">Dining philosophers</a></li><li><a href="/doc/solutions/Barbershop">Barbershop</a></li><li><a href="/doc/solutions/Baboon_crossing">Baboon crossing</a></li><li><a href="/doc/solutions/Search-insert-delete">Search-insert-delete</a></li><li><a href="/doc/solutions/Senate_bus">Senate bus</a></li><li><a href="/doc/solutions/Quicksort">Quicksort</a></li><li><a href="/doc/solutions/Dining_savages">Dining savages</a></li><li><a href="/doc/solutions/Faneuil_Hall">Faneuil Hall</a></li><li><a href="/doc/solutions/Observer_pattern">Observer pattern</a></li></ul></li><li><a href="/doc/solutions/SCOOP_implementation">SCOOP implementation</a></li><li><a href="/doc/solutions/SCOOP_papers">papers</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Networking">Networking</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelNet">EiffelNet</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelNet_Tutorial">EiffelNet Tutorial</a><ul> <li><a href="/doc/solutions/What_is_EiffelNet">What is EiffelNet</a></li><li><a href="/doc/solutions/Clients_and_servers">Clients and servers</a></li><li><a href="/doc/solutions/An_overview_of_EiffelNet_Mechanisms">An overview of EiffelNet Mechanisms</a></li><li><a href="/doc/solutions/Introduction_to_the_examples">Introduction to the examples</a></li><li><a href="/doc/solutions/Obtaining_a_finer_degree_of_control">Obtaining a finer degree of control</a></li><li><a href="/doc/solutions/Using_datagram_sockets">Using datagram sockets</a></li><li><a href="/doc/solutions/Event-driven_command_execution">Event-driven command execution</a></li><li><a href="/doc/solutions/A_more_complex_example">A more complex example</a></li><li><a href="/doc/solutions/Bibliography">Bibliography</a></li></ul></li><li><a href="/doc/solutions/EiffelNet_Class_Reference">EiffelNet Class Reference</a></li><li class="expandable "><a href="/doc/solutions/EiffelNet_Samples">EiffelNet Samples</a><ul> <li><a href="/doc/solutions/Advanced">Advanced</a></li><li><a href="/doc/solutions/Polling">Polling</a></li><li><a href="/doc/solutions/Predef">Predef</a></li><li><a href="/doc/solutions/Same_Machine">Same Machine</a></li><li><a href="/doc/solutions/Two_Machines">Two Machines</a></li></ul></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/Database_access">Database access</a><ul> <li class="expandable "><a href="/doc/solutions/ABEL">ABEL</a><ul> <li class="expandable "><a href="/doc/solutions/Tutorial">Tutorial</a><ul> <li><a href="/doc/solutions/Getting_started">Getting started</a></li><li><a href="/doc/solutions/Basic_operations">Basic operations</a></li><li><a href="/doc/solutions/Advanced_Queries">Advanced Queries</a></li><li><a href="/doc/solutions/Dealing_with_references">Dealing with references</a></li><li><a href="/doc/solutions/Tuple_queries">Tuple queries</a></li><li><a href="/doc/solutions/Error_handling">Error handling</a></li><li><a href="/doc/solutions/Accessing_an_existing_database">Accessing an existing database</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelStore">EiffelStore</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelStore_Tutorial">EiffelStore Tutorial</a><ul> <li class="expandable "><a 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cluster</a><ul> <li><a href="/doc/solutions/WEL_CHOOSE_COLOR_DIALOG">WEL_CHOOSE_COLOR_DIALOG</a></li><li><a href="/doc/solutions/WEL_CHOOSE_FOLDER_DIALOG">WEL_CHOOSE_FOLDER_DIALOG</a></li><li><a href="/doc/solutions/WEL_CHOOSE_FONT_DIALOG">WEL_CHOOSE_FONT_DIALOG</a></li><li><a href="/doc/solutions/WEL_OPEN_FILE_DIALOG">WEL_OPEN_FILE_DIALOG</a></li><li><a href="/doc/solutions/WEL_PRINT_DIALOG">WEL_PRINT_DIALOG</a></li><li><a href="/doc/solutions/WEL_SAVE_FILE_DIALOG">WEL_SAVE_FILE_DIALOG</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/WEL_Tutorial">WEL Tutorial</a><ul> <li><a href="/doc/solutions/Tutorial_Step_1">Tutorial Step 1</a></li><li><a href="/doc/solutions/Tutorial_Step_2">Tutorial Step 2</a></li><li><a href="/doc/solutions/Tutorial_Step_3">Tutorial Step 3</a></li><li><a href="/doc/solutions/Tutorial_Step_4">Tutorial Step 4</a></li><li><a href="/doc/solutions/Tutorial_Step_5">Tutorial Step 5</a></li><li><a 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Control</a></li><li><a href="/doc/solutions/Hello_World%21">Hello World!</a></li><li><a href="/doc/solutions/List_View">List View</a></li><li><a href="/doc/solutions/Magnify">Magnify</a></li><li><a href="/doc/solutions/MDI_%28Multiple_Document_Interface%29">MDI (Multiple Document Interface)</a></li><li><a href="/doc/solutions/Wel_Sample-_Menus">Wel Sample: Menus</a></li><li><a href="/doc/solutions/Minimal">Minimal</a></li><li><a href="/doc/solutions/Pizza">Pizza</a></li><li><a href="/doc/solutions/Printer">Printer</a></li><li><a href="/doc/solutions/Rich_Edit">Rich Edit</a></li><li><a href="/doc/solutions/Split_Area">Split Area</a></li><li><a href="/doc/solutions/Standard_Dialogs_Sample">Standard Dialogs Sample</a></li><li><a href="/doc/solutions/Timer">Timer</a></li><li><a href="/doc/solutions/Tree_View_Sample">Tree View Sample</a></li><li><a href="/doc/solutions/Unicode_Sample">Unicode Sample</a></li><li><a href="/doc/solutions/Windows_Sample">Windows Sample</a></li><li><a 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a COM Component</a></li><li><a href="/doc/solutions/Wizards-_Command_Line_Options">Wizards: Command Line Options</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelCOM_Library">EiffelCOM Library</a><ul> <li class="expandable "><a href="/doc/solutions/EiffelCOM_Interface_Content">EiffelCOM Interface Content</a><ul> <li><a href="/doc/solutions/Interfaces">Interfaces</a></li><li><a href="/doc/solutions/Structures">Structures</a></li></ul></li><li><a href="/doc/solutions/EiffelCOM_Class_Reference">EiffelCOM Class Reference</a></li></ul></li></ul></li><li class="expandable "><a href="/doc/solutions/ResourceBench">ResourceBench</a><ul> <li><a href="/doc/solutions/Features">Features</a></li><li><a href="/doc/solutions/Tour">Tour</a></li><li><a href="/doc/solutions/Troubleshooting">Troubleshooting</a></li></ul></li><li class="expandable "><a href="/doc/solutions/EiffelRibbon">EiffelRibbon</a><ul> <li><a href="/doc/solutions/EiffelRibbon_Design_Tool">EiffelRibbon Design Tool</a></li></ul></li></ul></li></ul></li></ul></li><li><a href="/doc/glossary/Glossary">Glossary</a></li><li><a href="/doc/faq/FAQ">FAQ</a></li><li class="expandable "><a href="/doc/contribute/How_to_contribute">Contribute</a><ul> <li><a href="/doc/contribute/How_to_contribute_to_documentation">To documentation</a></li><li><a href="/doc/contribute/Help_to_edit_documentation">Editing help</a></li></ul></li></ul> </div></div></div></div> </aside> <div class="content"> <header class="head"> <div id="breadcrumb"> <span class="ico"><img src="/theme/responsive-eiffel-org/images/ico-document.png" width="21" height="21" alt="Documentation"></span> <a href="https://www.eiffel.org/doc/eiffel">eiffel</a> :: ET: Agents </div> </header> <div><div class="wdocs-versions">Version<ul><li class="active"><a href="/doc/eiffel/ET-_Agents">25.02 (released) ...</a><ul class="popup-menu"><li><a href="/doc/version/trunk/eiffel/ET-_Agents">trunk (trunk)</a></li><li class="active"><a href="/doc/eiffel/ET-_Agents">25.02 (released)</a></li><li><a href="/doc/version/24.05/eiffel/ET-_Agents">24.05</a></li><li><a href="/doc/version/23.09/eiffel/ET-_Agents">23.09</a></li><li><a href="/doc/version/22.12/eiffel/ET-_Agents">22.12</a></li></ul></li></ul></div> <ul class="taxonomy term-1">Tags: <li><a href="/taxonomy/term/103">agent</a></li></ul> <div class="wikipage"><h1 class="wikititle">ET: Agents</h1> <div class="wiki-toc wiki-toc-auto"> <ol><a id="toc"></a><span class="title">Contents</span> <li><a href="#Objects_for_operations">Objects for operations</a></li> <li><a href="#Building_an_agent">Building an agent</a></li> <li><a href="#Operations_on_agents">Operations on agents</a></li> <li><a href="#Open_and_closed_arguments">Open and closed arguments</a></li> <li><a href="#Open_targets">Open targets</a></li> <li><a href="#Inline_agents">Inline agents</a></li> </ol> </div> <p>Our last mechanism, agents, adds one final level of expressive power to the framework describe so far. Agents apply object-oriented concepts to the modeling of operations. </p> <a id="Objects_for_operations"></a><h2>Objects for operations</h2> <p>Operations are not objects; in fact, object technology starts from the decision to separate these two aspects, and to choose object types, rather than the operations, as the basis for modular organization of a system, attaching each operation to the resulting modules -- the classes. </p> <p>In a number of applications, however, we may need objects that represent operations, so that we can include them in object structures that some other piece of the software will later traverse to uncover the operations and, usually, execute them. Such "operation wrapper" objects, called agents, are useful in a number of application areas such as: <br/> </p> <ul><li> GUI (Graphical User Interface) programming, where we may associate an agent with a certain event of the interface, such as a mouse click at a certain place on the screen, to prescribe that if the event occurs -- a user clicks there -- it must cause execution of the agent's associated operation. </li> <li> Iteration on data structures, where we may define a general-purpose routine that can apply an arbitrary operation to all the elements of a structure such as a list; to specify a particular operation to iterate, we will pass to the iteration mechanism an agent representing that operation. </li> <li> Numerical computation, where we may define a routine that computes the integral of any applicable function on any applicable interval; to represent that function and pass its representation to the integration routine, we will use an agent. </li> </ul> <p>Operations in Eiffel are expressed as routines, and indeed every agent will have an associated routine. Remember, however, that the fundamental distinction between objects and operations remains: an agent is an object, and it is not a routine; it represents a routine. As further evidence that this is a proper data abstraction, note that the procedure <code class="inline">call</code>, available on all agents to call the associated routine, is only one of the features of agents. Other features may denote properties such as the class to which the routine belongs, its precondition and postcondition, the result of the last call for a function, the number of arguments. </p> <a id="Building_an_agent"></a><h2>Building an agent</h2> <p>In the simplest form, also one of the most common, you obtain an agent just by writing<code> agent r</code></p> <p>where <code class="inline">r</code> is the name of a routine of the enclosing class. This is an expression, which you may assign to a writable entity, or pass as argument to a routine. Here for example is how you will specify event handling in the style of the EiffelVision 2 GUI library: <code> your_icon.click_actions.extend (agent your_routine)</code></p> <p>This adds to the end of <code class="inline">your_icon.click_actions</code> -- the list of agents associated with the "click" event for <code class="inline">your_icon</code>, denoting an icon in the application's user interface -- an agent representing <code class="inline">your_routine</code>. Then when a user clicks on the associated icon at execution, the EiffelVision 2 mechanisms will call the procedure <code class="inline">call</code> on every agent of the list, which for this agent will execute <code class="inline">your_routine</code>. This is a simple way to associate elements of your application, more precisely its "business model" (the processing that you have defined, directly connected to the application's business domain), with elements of its GUI. </p> <p>Similarly although in a completely different area, you may request the integration of a function <code class="inline">your_function</code> over the interval <code class="inline">0..1</code> through a call such as <code> your_integrator.integral (agent your_function, 0, 1)</code></p> <p>In the third example area cited above, you may call an iterator of EiffelBase through<code> your_list.do_all (agent your_proc)</code></p> <p>with <code class="inline">your_list</code> of a type such as <code class="inline">LIST [YOUR_TYPE]</code>. This will apply <code class="inline">your_proc</code> to every element of the list in turn. </p> <p>The agent mechanism is type-checked like the rest of Eiffel; so the last example is valid if and only if <code class="inline">your_proc</code> is a procedure with one argument of type <code class="inline">YOUR_TYPE</code>. </p> <a id="Operations_on_agents"></a><h2>Operations on agents</h2> <p>An agent <code class="inline">agent</code> <code class="inline">r</code> built from a procedure <code class="inline">r</code> is of type <code class="inline">PROCEDURE [T, ARGS]</code> where <code class="inline">T</code> represents the class to which <code class="inline">r</code> belongs and <code class="inline">ARGS</code> the type of its arguments. If <code class="inline">r</code> is a function of result type <code class="inline">RES</code>, the type is <code class="inline">FUNCTION [T, ARGS, RES]</code>. Classes <code class="inline">PROCEDURE</code> and <code class="inline">FUNCTION</code> are from the Kernel Library of EiffelBase, both inheriting from <code class="inline">ROUTINE [T, ARGS]</code>. </p> <p>Among the features of <code class="inline">ROUTINE</code> and its descendants the most important are <code class="inline">call</code>, already noted, which calls the associated routine, and <code class="inline">item</code>, appearing only in <code class="inline">FUNCTION</code> and yielding the result of the associated function, which it obtains by calling <code class="inline">call</code>. </p> <p>As an example of using these mechanisms, here is how the function <code class="inline">integral</code> could look like in our <code class="inline">INTEGRATOR</code> example class. The details of the integration algorithm (straight forward, and making no claims to numerical sophistication) do not matter, but you see the place were we evaluate the mathematical function associated with <code class="inline">f</code>, by calling <code class="inline">item</code> on <code class="inline">f</code>: <code> integral (f: FUNCTION [TUPLE [REAL], REAL]; low, high: REAL): REAL -- Integral of `f' over the interval [`low', `high'] require meaningful_interval: low <= high local x: REAL do from x := low invariant x >= low x <= high + step -- Result approximates the integral over -- the interval [low, low.max (x - step)] until x > high loop Result := Result + step * f.item ([x]) -- Here item is applied to f x := x + step end end</code></p> <p>Function <code class="inline">integral</code> takes three arguments: the agent <code class="inline">f</code> representing the function to be integrated, and the two interval bounds. When we need to evaluate that function for the value <code class="inline">x</code>, in the line <code> Result := Result + step * f.item ([x])</code></p> <p>we don't directly pass <code class="inline">x</code> to <code class="inline">item</code>; instead, we pass a one-element tuple <code class="inline">[x]</code>, using the syntax for manifest tuples introduced in <a href="/doc/eiffel/ET-_Other_Mechanisms#Tuple_types" class="wiki_link">"Tuple types"</a> . You will always use tuples for the argument to <code class="inline">call</code> and <code class="inline">item</code>, because these features must be applicable to any routine, and so cannot rely on a fixed number of arguments. Instead they take a single tuple intended to contain all the arguments. This property is reflected in the type of the second actual generic parameter to <code class="inline">f</code>, corresponding to <code class="inline">ARGS</code> (the formal generic parameter of <code class="inline">FUNCTION</code>): here it's <code class="inline">TUPLE [REAL]</code> to require an argument such as <code class="inline">[x]</code>, where <code class="inline">x</code> is of type <code class="inline">REAL</code>. </p> <p>Similarly, consider the agent that the call seen above:<code> your_icon.click_actions.extend (agent your_routine)</code></p> <p>added to an EiffelVision list. When the EiffelVision mechanism detects a mouse click event, it will apply to each element <code class="inline">item</code> of the list of agents, <code class="inline">your_icon.click_actions</code>, an instruction such as <code> item.call ([x, y])</code></p> <p>where <code class="inline">x</code> and <code class="inline">y</code> are the coordinates of the mouse clicking position. If <code class="inline">item</code> denotes the list element <code class="inline">agent</code> your_routine, inserted by the above call to <code class="inline">extend</code>, the effect will be the same as that of calling <code> your_routine (x, y)</code></p> <p>assuming that <code class="inline">your_routine</code> indeed takes arguments of the appropriate type, here <code class="inline">INTEGER</code> representing a coordinate in pixels. (Otherwise type checking would have rejected the call to <code class="inline">extend</code>.) </p> <a id="Open_and_closed_arguments"></a><h2>Open and closed arguments</h2> <p>In the examples so far, execution of the agent's associated routine, through <code class="inline">item</code> or <code class="inline">call</code>, passed exactly the arguments that a direct call to the routine would expect. You can have more flexibility. In particular, you may build an agent from a routine with more arguments than expected in the final call, and you may set the values of some arguments at the time you define the agent. </p> <p>Assume for example that a cartographical application lets a user record the location of a city by clicking on the corresponding position on the map. The application may do this through a procedure<code> record_city (cn: STRING; pop: INTEGER; x, y: INTEGER) -- Record that the city of name `cn' is at coordinates -- `x' and `y' with population `pop'.</code></p> <p>Then you can associate it with the GUI through a call such as<code> map.click_actions.extend (agent record_city (name, population, ?, ?))</code></p> <p>assuming that the information on the <code class="inline">name</code> and the <code class="inline">population</code> has already been determined. What the agent denotes is the same as <code class="inline">agent</code> <code class="inline">your_routine</code> as given before, where <code class="inline">your_routine</code> would be a fictitious two-argument routine obtained from <code class="inline">record_city</code> -- a four-argument routine -- by setting the first two arguments once and for all to the values given, <code class="inline">name</code> and <code class="inline">population</code>. </p> <p>In the agent <code class="inline">agent record_city (name, population, ?, ?)</code>, we say that these first two arguments, with their set values, are <strong>closed</strong>; the last two are <strong>open</strong>. The question mark syntax introduced by this example may only appear in agent expressions; it denotes open arguments. This means, by the way, that you may view the basic form used in the preceding examples, <code class="inline">agent your_routine</code>, as an abbreviation -- assuming your_routine has two arguments -- for <code class="inline">agent your_routine (?, ?)</code>. It is indeed permitted, to define an agent with all arguments open, to omit the argument list altogether; no ambiguity may result. </p> <p>For type checking, <code class="inline">agent record_city (name, population, ?, ?)</code> and <code class="inline">agent your_routine (?, ?)</code> are acceptable in exactly the same situations, since both represent routines with two arguments. The type of both is <code> PROCEDURE [TUPLE [INTEGER, INTEGER]]</code></p> <p>where the tuple type specifies the open operands. </p> <p>A completely closed agent, such as <code class="inline">agent your_routine (25, 32)</code> or <code class="inline">agent record_city (name, population, 25, 32)</code>, has the type <code class="inline">TUPLE</code>, with no parameters; you will call it with <code class="inline">call ([ ])</code>, using an empty tuple as argument. </p> <p>The freedom to start from a routine with an arbitrary number of arguments, and choose which ones you want to close and which ones to leave open, provides a good part of the attraction of the agent mechanism. It means in particular that in GUI applications you can limit to the strict minimum the "glue" code (sometimes called the controller in the so-called MVC, Model-View Controller, scheme of GUI design) between the user interface and "business model" parts of a system. A routine such as <code class="inline">record_city</code> is a typical example of an element of the business model, uninfluenced -- as it should be -- by considerations of user interface design. Yet by passing it in the form of an agent with partially open and partially closed arguments, you may be able to use it directly in the GUI, as shown above, without any "controller" code. </p> <p>As another example of the mechanism's versatility, we saw above an integral function that could integrate a function of one variable over an interval, as in<code> your_integrator.integral (agent your_function, 0, 1)</code></p> <p>Now assume that <code class="inline">function3</code> takes three arguments. To integrate <code class="inline">function3</code> with two arguments fixed, you don't need a new <code class="inline">integral</code> function; just use the same <code class="inline">integral</code> as before, judiciously selecting what to close and what to leave open: <code> your_integrator.integral (agent function3 (3.5, ?, 6.0), 0, 1)</code></p> <a id="Open_targets"></a><h2>Open targets</h2> <p>All the agent examples seen so far were based on routines of the enclosing class. This is not required. Feature calls, as you remember, were either unqualified, as in <code class="inline">f (x, y)</code>, or qualified, as in <code class="inline">a.g (x, y)</code>. Agents, too, have a qualified variant as in <code> agent a.g</code></p> <p>which is closed on its target <code class="inline">a</code> and open on the arguments. Variants such as <code class="inline">agent a.g (x, y)</code>, all closed, and <code class="inline">agent a.g (?, y)</code>, open on one argument, are all valid. </p> <p>You may also want to make the target open. The question mark syntax could not work here, since it wouldn't tell us the class to which feature <code class="inline">g</code> belongs, known in the preceding examples from the type of <code class="inline">a</code>. As in creation expressions, we must list the type explicitly; the convention is the same: write the types in braces, as in <code> agent {SOME_TYPE}.g agent {SOME_TYPE}.g (?, ?) agent {SOME_TYPE}.g (?, y)</code></p> <p>The first two of these examples are open on the target and both operands; they mean the same. The third is closed on one argument, open on the other and on the target. </p> <p>These possibilities give even more flexibility to the mechanism because they mean that an operation that needs agents with certain arguments open doesn't care whether they come from an argument or an operand of the original routine. This is particularly useful for iterators and means that if you have two lists<code> your_account_list: LIST [ACCOUNT] your_integer_list: LIST [INTEGER]</code></p> <p>you may write both<code> your_account_list.do_all (agent {ACCOUNT}.deposit_one_grand) your_integer_list.do_all (agent add_to_total)</code></p> <p>even though the two procedures used in the agents have quite different forms. We are assuming here that the first one, a feature of class <code class="inline">ACCOUNT</code>, is something like <code> deposit_one_grand -- Deposit one thousand into `Current'. do deposit (1000) end</code></p> <p>The procedure <code class="inline">deposit_one_grand</code> takes no arguments. In the <code class="inline">do_all</code> example above, its target is open. The target will be, in turn, each instance of <code class="inline">ACCOUNT</code> in <code class="inline">your_account_list</code>. </p> <p>In contrast, the other routine, assumed to be a feature of the calling class, does take an argument <code class="inline">x</code>: <code> add_to_total (x: INTEGER) -- Add `x' to the value of `total'. do total := total + x end</code></p> <p>Here, <code class="inline">total</code> is assumed to be an integer attribute of the enclosing class. In the <code class="inline">do_all</code> example, each instance of <code class="inline">your_integer_list</code> will fill the argument <code class="inline">x</code> left open in <code class="inline">add_to_total</code>.</p> <p>Without the versatility of playing with open and closed arguments for both the original arguments and target, you would have to write separate iteration mechanisms for these two cases. Here you can use a single iteration routine of <code class="inline">LIST</code> and similar classes of EiffelBase, <code class="inline">do_all</code>, for both purposes: <br/></p> <ul><li> Depositing money on every account in a list of accounts.</li> <li> Adding all the integers in a list of integers.</li> </ul> <a id="Inline_agents"></a><h2>Inline agents</h2> <p>In the agent discussion above, it has been assumed that there already exists some routine that we wish to represent with an agent. However, sometimes the only usage of such a routine could be as an agent ... that is, the routine does not make sense as a feature of the class in question. In these cases, we can use <strong>inline agents</strong>. With an inline agent we write the routine within the agent declaration. </p> <p>If we consider the use of agents instead of class features in the two <code class="inline">do_all</code> examples in the previous section, the agents would be coded as follows:</p> <p><code> your_account_list.do_all (agent (a: ACCOUNT) do a.deposit (1000) end)</code></p> <p>and</p> <p><code> your_integer_list.do_all (agent (i: INTEGER) do total := total + i end)</code></p> <p>The syntax of the inline agent corresponds to the syntax of a routine. Immediately following the <code class="inline">agent</code> keyword are the formal arguments and in the case of functions the type for <code class="inline">Result</code>. Inline agents can have <code class="inline">local</code> entities, preconditions, and postconditions, just like any routine. </p> <p>Inline agents do not have access to the local entities of the routine in which they are coded. So, if it is necessary to use the routine's local variables, they must be passed as arguments to the inline agent. </p> <p>Here's an example of an inline agent which is a function. It is used in the context of a check to see if every element of <code class="inline">your_integer_list</code> is positive:</p> <p><code> your_integer_list.for_all (agent (i: INTEGER): BOOLEAN do Result := (i > 0) ensure definition: Result = (i > 0) end)</code></p> <p>Inline agents are interesting also as an implementation of the notion of <a href="http://en.wikipedia.org/wiki/Closure_(computer_science)" class="wiki_ext_link">closures</a> in computer science. </p> <p>Agents provide a welcome complement to the other mechanisms of Eiffel. They do not conflict with them but, when appropriate -- as in the examples sketched in this section -- provide clear and expressive programming schemes, superior to the alternatives.</p> <p>Compatibility note: earlier versions of the agent classes (ROUTINE, PROCEDURE, FUNCTION, PREDICATE) had an extra initial generic parameter, for which ANY was generally used. The compiler has been engineered to accept the old style in most cases.</p> <p><p class="tpl seealso-message"><a href="/doc-image/LogoInformation"><img src="/doc-image/25.02/_images/tpl_Information.png" border="0" width="24" alt=""/></a> <strong>See Also:</strong> <a href="/doc/solutions/Event_Programming_with_Agents" class="wiki_link">Event Programming with Agents</a> </p> </p> </div> <div class="wdocs-nav"><div class="wdocs-nav-section">Back to <a href="/doc/eiffel/An_Eiffel_Tutorial_%28ET%29" class="wdocs-folder">Tutorial</a></div><div class="wdocs-uuid"><a href="/doc/uuid/ba49a80d-5ddf-8b30-4943-528974fd0ddd">Permanent link</a></div> </div> <div class="wdocs-cache-info">cached: 02/26/2025 6:37:29.000 AM</div></div> <div class="roc-comments-ext"> <div id="remark42"></div> <script> var remark_config = { site_id: 'eiffel-org-comments', url: 'https://www.eiffel.org/doc/uuid/ba49a80d-5ddf-8b30-4943-528974fd0ddd', // Replace PAGE_URL with your page's canonical URL variable max_shown_comments: 25, // optional param; if it isn't defined default value (15) will be used theme: 'dark', // optional param; if it isn't defined default value ('light') will be used }; (function() { var d = document, s = d.createElement('script'); s.src = 'https://remark.eiffel.org/web/embed.js'; // prepends this address with domain where remark42 is placed (d.head || d.body).appendChild(s); })(); </script> </div> </div> </div> </section> </main>  <footer id="footer"> <div class="container"> <nav class="footer-nav"> <ul class="grid-5 has-gutter"> <li class="one-sixth"><a href="https://www.eiffel.org/welcome">Welcome</a> <ul> <li><a href="https://www.eiffel.org/purpose">Purpose</a></li> <li><a href="https://www.eiffel.org/news">News</a></li> <li><a href="https://www.eiffel.org/updates">Updates</a></li> <li><a href="https://www.eiffel.org/forum">Forum</a></li> <li><a href="https://www.eiffel.org/community">Community</a></li> <li><a href="https://www.eiffel.org/contact">Contact</a></li> <li> <a href="/account/roc-login?destination=doc%2Feiffel%2FET-_Agents">Sign in</a> </li> </ul> </li> <li class="one-sixth"><a href="https://www.eiffel.org/documentation">Documentation</a> <ul> <li><a href="https://www.eiffel.org/doc/eiffel">Eiffel</a></li> <li><a href="https://www.eiffel.org/doc/eiffelstudio">EiffelStudio</a></li> <li><a href="https://www.eiffel.org/doc/solutions">Solutions</a></li> <li><a href="https://www.eiffel.org/doc/glossary">Glossary</a></li> <li><a href="https://www.eiffel.org/doc/faqs">FAQs</a></li> <li><a href="https://www.eiffel.org/contribute">Contribute</a></li> </ul> </li> <li class="one-sixth"><a href="https://www.eiffel.org/resources">Resources</a> <ul> <li><a href="https://www.eiffel.org/resources/libraries">Libraries</a></li> <li><a href="https://www.eiffel.org/resources/tools">Tools</a></li> <li><a href="https://www.eiffel.org/resources/wish_list">Wish list</a></li> <li><a href="https://www.eiffel.org/resources/videos">Videos</a></li> <li><a href="https://www.eiffel.org/resources/follow_us">Follow us</a></li> </ul> </li> <li class=""> <div class="btn-holder"> <a class="btn btn-download" href="https://www.eiffel.org/downloads">Download Now</a> <a class="btn btn-tryonline" href="https://www.eiffel.org/try_eiffel">Try Eiffel Online</a> <a class="btn btn-contribute" href="https://www.eiffel.org/contribute">Contribute</a> <a class="btn btn-account" href="/account/roc-login?destination=doc%2Feiffel%2FET-_Agents">Sign in</a> </div> </li> <li class="one-sixth"> <ul class="social-networks"> <li><a class="facebook" target="_blank" href="https://www.facebook.com/pages/Eiffel-Programming-Language/235981463124887">Facebook</a></li> <li><a class="youtube" target="_blank" href="http://www.youtube.com/user/EiffelLanguage">You Tube</a></li> <li><a class="twitter" target="_blank" href="https://twitter.com/Eiffel_Language">Twitter</a></li> </ul> </li> </ul> </nav>  <div style="float: right">Built with the Eiffel ROC CMS and the <a href="http://www.eiffelweb.org">EiffelWeb framework</a>.</div> </div> </footer> <script src="/theme/responsive-eiffel-org/js/wdownloads.js"></script> <script src="/theme/responsive-eiffel-org/js/home.js"></script> <link href="/theme/responsive-eiffel-org/js/google-code-prettify-eiffel/styles/lang-eiffel.css" type="text/css" rel="stylesheet" /> <script src="https://cdn.jsdelivr.net/gh/google/code-prettify@master/loader/run_prettify.js"></script> <script src="/theme/responsive-eiffel-org/js/google-code-prettify-eiffel/src/lang-eiffel.js"></script> <script src="https://www.google.com/recaptcha/api.js" async defer></script> </div> </body> </html>