lexical description problem in language report?
Memovich, Gary
GARY.MEMOVICH@kla-tencor.com
Wed, 18 Jul 2001 11:51:40 -0700
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I believe I've found a problem, or at least a confusion, in the Haskell 98
Language Report. The section on lexical structure seems to use the term
"lexeme" in an inconsistent way. "lexeme" is one of the productions in the
lexical grammar in section 2.2, but the term is also used in section 2.3
where it is claimed that the string "{-" is a lexeme. However the string
"{-" cannot be produced by the given grammar production. Is section 2.3,
and the discussion of the maximal-munch rule, using the term lexeme in a
different way than the grammar production in section 2.2? If so, maybe a
new term should be introduced such as "rawlexeme", with a production like:
rawlexeme -> lexeme | opencom | closecom | dashes
Then perhaps the maximal-munch rule could be described in terms of
"rawlexeme".
Any thoughts?
-- Gary
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<DIV><FONT face=Arial size=2><SPAN class=312112418-18072001>I believe I've found
a problem, or at least a confusion, in the Haskell 98 Language Report. The
section on lexical structure seems to use the term "lexeme" in an
inconsistent way. "lexeme" is one of the productions in the lexical
grammar in section 2.2, but the term is also used in section 2.3 where it is
claimed that the string "{-" is a lexeme. However the string "{-" cannot be
produced by the given grammar production. Is section 2.3, and the
discussion of the maximal-munch rule, using the term lexeme in a different way
than the grammar production in section 2.2? If so, maybe a new term should
be introduced such as "rawlexeme", with a production like:</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=312112418-18072001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=312112418-18072001>rawlexeme ->
lexeme | opencom | closecom | dashes</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=312112418-18072001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=312112418-18072001>Then perhaps the
maximal-munch rule could be described in terms of
"rawlexeme".</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=312112418-18072001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=312112418-18072001>Any
thoughts?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=312112418-18072001>--
Gary</SPAN></FONT></DIV></BODY></HTML>
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