Factor handbook » The language » Syntax » Parse-time word lookup » Word lookup errors


Variable description
If set to a true value, the behavior of the parser when encountering an unknown word name is changed. If only one loaded vocabulary has a word with this name, instead of throwing an error, the parser adds the vocabulary to the search path and prints a parse note. Off by default.

This feature is intended to help during development. To generate a USING: form automatically, enable auto-use?, load the source file, and copy and paste the USING: form printed by the parser back into the file, then disable auto-use?. See Word lookup errors.