PARSE does not skip leading delimiters, and you cannot specify that you want to parse for white space.
WORD skips leading delimiters, but you cannot specify parsing for white space, it creates a counted string (not the preferred representation), the length of the string is therefore limited, it requires a separate buffer (typically limitinmg the string size even more, and the copying to that buffer consumes time); WORD also requires passing a delimiter, although skipping leading delimiters only makes sense for white-space delimiters. ANS Forth does not specify the lifetime of the resulting string precisely.
PARSE-WORD ( "Skip leading white space and parse name delimited by a white space character.
name " -- c-addr u ) CORE-EXT
c-addr is the address within the input buffer and u is the length of the selected string. If the parse area is empty or contains only white space, the resulting string has length zero.
PARSE-WORD some-name TYPE
Several systems have implemented a PARSE-WORD compatible with this specification, e.g., Gforth and Quartus.
A number of systems have been named that define a PARSE-WORD incompatible with this specification (e.g., they often pass a delimiter on the stack). The systems mentioned are MPE's VFX Forth and all MPE v6+ embedded targets, MinForth, CHForth, F83, Jforth, 4th. Of these systems VFX, MinForth and CHForth are ANS Forth implementations, F83, 4th and JForth are not (although 4th partially stays close to ANS Forth). Coos Haak (CHForth) indicated that the next version of CHForth will have a PARSE-WORD compatible to this specification.
PARSE-WORD in Mops works like the one proposed here, but it refills the input buffer if the parse area is empty or contains only white space.
NextWord (conflict: exists with different meaning in Win32Forth) (existing practice: SP-Forth/4) TOKEN Supported by: Alex McDonald Could live with it: Bernd Paysan Strongly opposed: Michael L Gassanenko NAME (existing practice: exists with this meaning in Gforth) Supported by: Coos Haak Supported by: Albert van der Horst Could live with it: Bernd Paysan (Michael Gassenenko points out that it does not fit with >NAME NAME>) EXTRACTWORD EXTRACT-WORD Supported by: Ward McFarland GET-WORD GET-NAME GET-TOKEN PARSE-NAME Supported by: Stephen Pelc Second choice: Albert van der Horst Could live with it: Ward McFarland Could also support: Alex McDonald Could live with it: Marcel Hendrix Can live with it: David N. Williams Supported by: Anton Ertl Is happy with it: Mike Hore PARSE-STREAMSome people support PARSE-WORD despite the conflict: Charles Melice, Ward McFarland, Bernd Paysan.
One other probably widely used and accepted white space character is TAB, but extending the definition of white space may be better left to another RfD.
Systems that support TAB: Gforth, VFX Forth and MPE v6+ embedded systems.