diff options
Diffstat (limited to 'src/nbc/substitution.sml')
| -rw-r--r-- | src/nbc/substitution.sml | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/nbc/substitution.sml b/src/nbc/substitution.sml new file mode 100644 index 0000000..57d55cf --- /dev/null +++ b/src/nbc/substitution.sml @@ -0,0 +1,26 @@ +signature SUBSTITUTION = sig + val substitute: (string -> string) -> string -> string option +end + +structure Substitution :> SUBSTITUTION = struct + structure LrVals = SubstitutionGrmLrValsFun (structure Token = LrParser.Token) + structure Lex = SubstitutionLexFun (structure Tokens = LrVals.Tokens) + structure Parser = JoinWithArg ( + structure ParserData = LrVals.ParserData + structure Lex = Lex + structure LrParser = LrParser + ) + fun substitute lookup source = + let + val position = ref 0 + val instream = TextIO.openString source + fun read n = TextIO.inputN (instream, n) + val lexer = Parser.makeLexer read (ref 0) + fun error (_, _, _) = () + val (result, _) = Parser.parse (0, lexer, error, lookup) + val () = TextIO.closeIn instream + in + SOME result + end + handle Parser.ParseError => NONE +end |