lex rules

Hi All,


        Sorry if this isn't the right place. Are there any lex/yacc specific
forums?


I have some lex code below:


ws [ \t\r\n]+
eq {ws}?"="{ws}?
dq "\""
sq "'"


VersionNum [a-zA-Z0-9_.:]+
EncName [A-Za-z][A-Za-z0-9._]*


VersionInfo {ws}"version"{eq}({dq}|{sq}){VersionNum}({dq}|{sq})
EncodingDecl {ws}"encoding"{eq}({dq}|{sq}){EncName}({dq}|{sq})
StandaloneDecl {ws}"standalone"{eq}({dq}|{sq})("yes"|"no")({dq}|{sq})
XmlDecl "<?xml"{VersionInfo}{EncodingDecl}?{StandaloneDecl}?{ws}?"?>"


%%
{XmlDecl} { return XMLDECL; }


Note that the EncodingDecl and StandaloneDecl should be optional. Yet, when
I have
<?xml version="1.0" ?> as input it does not match {XmlDecl}. If I
remove{EncodingDecl} and {StandaloneDecl} then it works fine (or if I expand
the input to use them). Why is this and how do I fix it?




Cheers,


Blake
[I think I've seen bugs before in nested named patterns. -John]

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