// stdio.asm:	WORD p_stream_nchars,'STREAM-NCHARS',fasm

anchor:p_stream_nchars[]

=== Word: STREAM-NCHARS
....
Data stack: ( stream -- n )
....

"STREAM-NCHARS" is a function word that scans ahead in the stream
buffer for the next non-whitespace character, and returns its position
relative to the end of the buffer. This is done without changing the
stream (or filling it by reading the backing file).