Regex: find words following on "^\w+\s+" - New Syntax Definition (MMIX) - Sublime Text 3

Question

I am trying to create a syntax definition file for the MMIX assembler language. These files are used by Sublime Text 3 to highlight the syntax of a text/source file and as of late are written in YAML.

Instructions that follow on ^\s+ are highlighted correct, ^\s+ADD\s+ for example. (f.l.t.r: Syntax definition file, MMIX source)

However, instructions following a label and white space get not highlighted alone, but rather everything from the beginning of the line to end end of the regexp gets highlighted.

^\w+\s+IS\s+ does not work right.

I recently learned some theory about regular expressions, but never have used them on a computer.

How can I achieve, that only the token IS gets highlighted?

Answer 1

You can use a Positive Lookahead, try the following.

IS(?=\s)