Re: [TUHS] eqn anomaly

I was surprised that eqn parses the macro call below as having two arguments, each with an unmatched ". .EQ define f % $1 % f("a,b") .EN Ralph Corderoy found that the comma can be hidden by replacing it with \N'44'. A somewhat cleaner way to hide it is .EQ define f % $1 % define comma % , % f(a comma b) .EN This works too. .EQ f(f(a comma b)) .EN [Note for cognoscenti. Eqn's practice in expanding macro arguments clashes with troff's. Eqn expands nested calls after substitution in the outer macro definition; troff expands while collecting arguments of the outer call. I've found no documentation of the eqn behavior.] The classical man page for eqn asserts categorically, `Strings enclosed in double quotes " " are passed through untouched.' Unfortunately the version of Kernighan/Cherry User's Guide that describes macros with arguments says little about how arguments are parsed except that they are separated by commas--nothing about whether commas are hidden by parentheses or quotes. Certainly splitting at a comma in a quoted string violates the plain meaning of the man-page assertion. If anyone has v10 (or perhaps something else after v7) running, I'd be grateful to learn what classic eqn actually did. I'm morally certain that if it did split and anyone had complained to Brian, he would have fixed it. These observations lead me to file a bug report. Doug