Built-in Function

Four things are matched so often that APM builds them in. They are functions, not actions you declare: write the name, with no parentheses.

Action	Matches
spc	one space or tab
nl	one line break
eol	the end of a line: a line break, or the end of the input
eof	the end of the input, matching zero width

line := <A:Z>+ . eol;
last := <A:Z>+ . eof;

eol and eof

eol succeeds at a line break or at the end of the input, and consumes the line break when that is what it found. eof succeeds only where there is nothing left, and consumes nothing — it is a check on position, not a match on text.

So eol is what a line-oriented grammar wants, and eof is how you insist the whole input was used.

See also

spc and nl are what usually fill an Inbetween block. They save you writing your own space and newline parsers, which is all they are for — using them is entirely optional.

All four names are reserved, so no action of yours may be called spc, nl, eol or eof.