As I recall, yacc's default token is the ASCII value of a character. The lexer in this case needn't be more complicated, therefore, than getchar. The rule in question means "An `a' is expected here." Were there a `b' in the input, and none of the other paths through the rules matched, the program reports syntax error. A little shell scripting to count the syntax errors, a bit of subtraction, is the tally of matching strings.
I hope that some part of this answer is satisfactory. May 2021 be better, much, than 2020. |Raul Miller rauldmiller at gmail.com |Thu Dec 31 15:16:52 UTC 2020 | |what is the significance of this line: | |a4: 'a' ; | |? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
