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Diffstat (limited to 'gramlib/plexing.mli')
| -rw-r--r-- | gramlib/plexing.mli | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/gramlib/plexing.mli b/gramlib/plexing.mli new file mode 100644 index 0000000000..eed4082e00 --- /dev/null +++ b/gramlib/plexing.mli @@ -0,0 +1,37 @@ +(* camlp5r *) +(* plexing.mli,v *) +(* Copyright (c) INRIA 2007-2017 *) + +(** Lexing for Camlp5 grammars. + + This module defines the Camlp5 lexer type to be used in extensible + grammars (see module [Grammar]). It also provides some useful functions + to create lexers. *) + +type pattern = string * string + (* Type for values used by the generated code of the EXTEND + statement to represent terminals in entry rules. +- The first string is the constructor name (must start with + an uppercase character). When it is empty, the second string + is supposed to be a keyword. +- The second string is the constructor parameter. Empty if it + has no parameter (corresponding to the 'wildcard' pattern). +- The way tokens patterns are interpreted to parse tokens is done + by the lexer, function [tok_match] below. *) + +exception Error of string + (** A lexing error exception to be used by lexers. *) + +(** Lexer type *) + +type 'te lexer = + { tok_func : 'te lexer_func; + tok_using : pattern -> unit; + tok_removing : pattern -> unit; + tok_match : pattern -> 'te -> string; + tok_text : pattern -> string; + } +and 'te lexer_func = char Stream.t -> 'te Stream.t * location_function +and location_function = int -> Loc.t + (** The type of a function giving the location of a token in the + source from the token number in the stream (starting from zero). *) |