Editing Smalltalk (section)

=== Browser ===
Smalltalk-80 derived systems organize classes within "system categories", such as <code>Kernel-Numbers</code>, <code>Kernel-Objects</code>, <code>Collections-Abstract</code>, <code>Collections-Sequenceable</code>, etc, and within classes methods are organized in named categories such as <code>accessing</code>, <code>arithmetic</code>, <code>instance creation</code>, etc. From this follows the classic five paned browser, with four panes in the upper half of the window containing from high to left the list of system categories, that when one is selected displays in the second window the list of classes in that category, that when one is selected displays the list of message categories in the selected class, that when one is selected displays in the last pane the selectors of the methods in the selected category in the selected class. When one of the selectors in the fourth pane is selected the source for that method is displayed in the fifth pane. If only a category is selected and not a method, the fifth pane shows a template for defining a new method. If a system category is selected but no class, a template for creating a class in the category is displayed. Various pop-up menus allow one to query the tool such as searching for a class by name, finding all senders of a selected message, or all implementors of the message, and so on. In this way the browser is both a code reading and system exploration tool and a code authoring tool.[[File:Squeak System Browser Fraction.png|thumb|right|Squeak System Browser on Fraction's lcm: method]]