REGEXP_PARSER signature
signature REGEXP_PARSER
structure AwkSyntax : REGEXP_PARSER
This is the signature of a concrete syntax for regular expressions. It provides functionality to converts strings of characters into the abstract syntax of regular expressions given in the RegExpSyntax structure. This is done by converting a character reader into an abstract syntax reader.
The AwkSyntax structure is a structure matching this signature. It implements the AWK syntax for specifying regular expressions. The syntax is defined on pp. 28-30 of "The AWK Programming Language," by Aho, Kernighan and Weinberger.
Meta characters:
"\" "^" "$" "." "[" "]" "|" "(" ")" "*" "+" "?"
Atomic REs:
c matches the character c (for non-metacharacters c)
"^" matches the empty string at the beginning of a line
"$" matches the empty string at the end of a line
"." matches any single character (except \000 and \n)
Escape sequences:
"\b" matches backspace
"\f" matches formfeed
"\n" matches newline (linefeed)
"\r" matches carriage return
"\t" matches tab
"\"ddd matches the character with octal code ddd.
"\"c matches the character c (e.g., \\ for \, \" for ")
"\x"dd matches the character with hex code dd.
Compound regular expressions:
A"|"B matches A or B
AB matches A followed by B
A"?" matches zero or one As
A"*" matches zero or more As
A"+" matches one or more As
"("A")" matches A
val scan : (char,'a) StringCvt.reader -> (RegExpSyntax.syntax,'a) StringCvt.reader
scan getc
RegExpSyntax
Last Modified June 3, 1998
Comments to John Reppy
Copyright © 1998 Bell Labs, Lucent Technologies