ocaml/otherlibs/str/str.ml

111 lines
3.8 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
type regexp
external compile_regexp: string -> bool -> regexp = "str_compile_regexp"
external string_match: regexp -> string -> int -> bool = "str_string_match"
external search_forward: regexp -> string -> int -> int = "str_search_forward"
external search_backward: regexp -> string -> int -> int = "str_search_backward"
external beginning_group: int -> int = "str_beginning_group"
external end_group: int -> int = "str_end_group"
external replacement_text: string -> string -> string = "str_replacement_text"
let quote s =
let len = String.length s in
let buf = String.create (2 * len) in
let pos = ref 0 in
for i = 0 to len - 1 do
match s.[i] with
'[' | ']' | '*' | '.' | '\\' | '?' | '+' | '^' | '$' as c ->
buf.[!pos] <- '\\'; buf.[!pos + 1] <- c; pos := !pos + 2
| c ->
buf.[!pos] <- c; pos := !pos + 1
done;
String.sub buf 0 !pos
let string_before s n = String.sub s 0 n
let string_after s n = String.sub s n (String.length s - n)
let first_chars s n = String.sub s 0 n
let last_chars s n = String.sub s (String.length s - n) n
let regexp e = compile_regexp e false
let regexp_case_fold e = compile_regexp e true
let regexp_string s = compile_regexp (quote s) false
let regexp_string_case_fold s = compile_regexp (quote s) true
let group_beginning n =
if n < 0 or n >= 10 then invalid_arg "Str.group_beginning" else
let pos = beginning_group n in
if pos = -1 then raise Not_found else pos
let group_end n =
if n < 0 or n >= 10 then invalid_arg "Str.group_end" else
let pos = end_group n in
if pos = -1 then raise Not_found else pos
let matched_group n txt =
let b = group_beginning n and e = group_end n in String.sub txt b (e-b)
let match_beginning () = group_beginning 0
and match_end () = group_end 0
and matched_string txt = matched_group 0 txt
let substitute_first expr repl_fun text =
try
let pos = search_forward expr text 0 in
String.concat "" [string_before text pos;
repl_fun text;
string_after text (match_end())]
with Not_found ->
text
let global_substitute expr repl_fun text =
let rec replace start =
try
let pos = search_forward expr text start in
let repl_text = repl_fun text in
String.sub text start (pos-start) ::
repl_text ::
replace (match_end())
with Not_found ->
[string_after text start] in
String.concat "" (replace 0)
let global_replace expr repl text =
global_substitute expr (replacement_text repl) text
and replace_first expr repl text =
substitute_first expr (replacement_text repl) text
let bounded_split expr text num =
let start =
if string_match expr text 0 then match_end() else 0 in
let rec split start n =
if start >= String.length text then [] else
if n = 1 then [string_after text start] else
try
let pos = search_forward expr text start in
String.sub text start (pos-start) :: split (match_end()) (n-1)
with Not_found ->
[string_after text start] in
split start num
let split expr text = bounded_split expr text 0