IDE tip: AST-based Selection

AST-based selection is a feature which lets you select the surrounding "block", based not on syntactic clues (such as braces and parentheses, as is offered by practically all editors), but based on the parse tree created by the compiler (or the "AST", for abstract syntax tree). In NetBeans, there are two complementary actions to deal with AST selection: Select Surrounding and its reverse. They have other names which I can never remember, but the keybindings are as follows: Select surrounding block Mac: Ctrl-Shift-. (period) Windows/Linux/Solaris/Others: Alt-Shift-. Reverse: Mac: Ctrl-Shift-, (comma) Windows/Linux/Solaris/Others: Alt-Shift-, On my U.S. keyboard, the comma and period keys are marked with "" for the shift key which is somewhat reminiscent of blocks. These two actions cooperate and are stateful: they remember the original caret location such that you can "go back". Here's how it works. You want to select something surrounding the caret, say the whole method. In that case you just hit the surrounding action. With your fingers holding ctrl and shift you hit dot -- once, twice, bam bam bam. If you do it quickly you might "overshoot" and go one too far and select say the whole class instead of just the method. If so just press comma and voila, it goes back one step down the selection hierarchy you just came up. This makes this a very quick way to select code blocks -- no more need to gra...

Date: March, 30 2010
Url: http://blogs.sun.com/tor/entry/ide_tip_ast_based_selection

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