{ $description "Annotates a word definition to enter the single stepper if the quotation yields true. The quotation has access to the datastack as it exists just before " { $snippet "word" } " is called." }
{ $description "A breakpoint for parsing words. When this word is executed, it copies the definition of the following parsing word, prepends a " { $link break } " to it so that it is the first word to be executed when the definition is called, and calls this new definition.\n\nWhen the walker tool opens, execution will still be inside " { $link POSTPONE:B: } ". To step out of B: and into the parsing word, do just that: jump out with O, then into with I." } ;
"In addition to invoking the walker explicitly through the UI, it is possible to set breakpoints on words using words in the " { $vocab-link "tools.walker" } " vocabulary."
$nl
"Annotating a word with a breakpoint (see " { $link "tools.annotations" } "):"
"Note that because the walker calls various core library and UI words while rendering its own user interface, setting a breakpoint on a word such as " { $link append } " or " { $link + } " will hang the UI.";
