diff options
| -rw-r--r-- | parsing/lexer.ml4 | 22 | ||||
| -rw-r--r-- | parsing/lexer.mli | 1 |
2 files changed, 23 insertions, 0 deletions
diff --git a/parsing/lexer.ml4 b/parsing/lexer.ml4 index c827ab381a..7a1421592c 100644 --- a/parsing/lexer.ml4 +++ b/parsing/lexer.ml4 @@ -59,6 +59,25 @@ let ttree_find ttree str = in proc_rec ttree 0 +(* Removes a string from a dictionary: returns an equal dictionary + if the word not present. *) +let ttree_remove ttree str = + let rec remove tt i = + if i == String.length str then + {node = None; branch = tt.branch} + else + let c = str.[i] in + let br = + match try Some (CharMap.find c tt.branch) with Not_found -> None with + | Some tt' -> + CharMap.add c (remove tt' (i + 1)) (CharMap.remove c tt.branch) + | None -> tt.branch + in + { node = tt.node; branch = br } + in + remove ttree 0 + + (* Errors occuring while lexing (explained as "Lexer error: ...") *) type error = @@ -171,6 +190,9 @@ let add_keyword str = check_keyword str; token_tree := ttree_add !token_tree str +let remove_keyword str = + token_tree := ttree_remove !token_tree str + (* Adding a new token (keyword or special token). *) let add_token (con, str) = match con with | "" -> add_keyword str diff --git a/parsing/lexer.mli b/parsing/lexer.mli index 1a3a10aaae..1b40d7f178 100644 --- a/parsing/lexer.mli +++ b/parsing/lexer.mli @@ -21,6 +21,7 @@ type error = exception Error of error val add_token : string * string -> unit +val remove_keyword : string -> unit val is_keyword : string -> bool val location_function : int -> loc |