Similarly, I try to bake the documentation directly into the code. Eg (from a shell): OPTION(*line=='[',"[EXPR]","the result of evaluating EXPR as a math exp

Similarly, I try to bake the documentation directly into the code. Eg (from a shell): OPTION(*line=='[',"[EXPR]","the result of evaluating EXPR as a math expression (see -?m)") { ... } qsh -?s | grep -F '$[' '$[EXPR]': the result of evaluating EXPR as a math expression (see -?m) So OPTION does triple duty as 'comments', documentation, and the actual test for what kind of substitution is being parsed. This tends to be at the mercy of code structure though.