HELP COLON Revised by Fran Evelyn, July 85
The colon, :, has two uses in POP-11 syntax.
The first use is to flag the preceding word as a label (see HELP *LABELS),
which may then be the target of a *GOTO. For example:
loop: n + 1 -> n;
.............
goto loop;
The second use is in matching; the colon can be used to restrict the match in
various ways, e.g.
??<variable>:integer e.g. ??x:3
Restrict the variable to match the given number of items
?<variable>:<procedure name> e.g. ?x:isword
?<variable>:<procedure> e.g. ?x: % ismorethan(%0%) %
Before allowing the match, apply the procedure to the
matching item. If the result is FALSE, don't allow the
match to succeed. If the result is TRUE, allow it. If
the result is anything else, allow the match, but bind
the result to the variable.
??<variable>:<procedure name> e.g. ??x:noun_prhase
??<variable>:<procedure> e.g. ??x: % refersto(%item%) %
See HELP *MATCHES - using the POP-11 matcher