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(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Module [Str]: regular expressions and high-level string processing *)
(*** Regular expressions *)
type regexp
(* The type of compiled regular expressions. *)
val regexp: string -> regexp
(* Compile a regular expression. The syntax for regular expressions
is the same as in Gnu Emacs. The special characters are
[$^.*+?[]\]. The following constructs are recognized:
- [. ] matches any character except newline
- [* ] (postfix) matches the previous expression zero, one or
several times
- [+ ] (postfix) matches the previous expression one or
several times
- [? ] (postfix) matches the previous expression once or
not at all
- [[..] ] character set; ranges are denoted with [-], as in [a-z];
an initial [^], as in [^0-9], complements the set
- [^ ] matches at beginning of line
- [$ ] matches at end of line
- [\| ] (infix) alternative between two expressions
- [\(..\)] grouping and naming of the enclosed expression
- [\1 ] the text matched by the first [\(...\)] expression
([\2] for the second expression, etc)
- [\b ] matches word boundaries
- [\ ] quotes special characters. *)
val regexp_case_fold: string -> regexp
(* Same as [regexp], but the compiled expression will match text
in a case-insensitive way: uppercase and lowercase letters will
be considered equivalent. *)
(*** String matching and searching *)
external string_match: regexp -> string -> int -> bool = "str_string_match"
(* [string_match r s start] tests whether the characters in [s]
starting at position [start] match the regular expression [r].
The first character of a string has position [0], as usual. *)
external search_forward: regexp -> string -> int -> int = "str_search_forward"
(* [search_forward r s start] searchs the string [s] for a substring
matching the regular expression [r]. The search starts at position
[start] and proceeds towards the end of the string.
Return the position of the first character of the matched
substring, or raise [Not_found] if no substring matches. *)
external search_backward: regexp -> string -> int -> int = "str_search_backward"
(* Same as [search_forward], but the search proceeds towards the
beginning of the string. *)
val matched_string: string -> string
(* [matched_string s] returns the substring of [s] that was matched
by the latest [string_match], [search_forward] or [search_backward].
The user must make sure that the parameter [s] is the same string
that was passed to the matching or searching function. *)
val match_beginning: unit -> int
val match_end: unit -> int
(* [match_beginning()] returns the position of the first character
of the substring that was matched by [string_match],
[search_forward] or [search_backward]. [match_end()] returns
the position of the character following the last character of
the matched substring. *)
val matched_group: int -> string -> string
(* [matched_group n s] returns the substring of [s] that was matched
by the [n]th group [\(...\)] of the regular expression during
the latest [string_match], [search_forward] or [search_backward].
The user must make sure that the parameter [s] is the same string
that was passed to the matching or searching function. *)
val group_beginning: int -> int
val group_end: int -> int
(* [group_beginning n] returns the position of the first character
of the substring that was matched by the [n]th group of
the regular expression. [group_end n] returns
the position of the character following the last character of
the matched substring. *)
(*** Replacement *)
val global_replace: regexp -> string -> string -> string
(* [global_replace regexp repl s] returns a string identical to [s],
except that all substrings of [s] that match [regexp] have been
replaced by [repl]. The replacement text [repl] can contain
[\1], [\2], etc; these sequences will be replaced by the text
matched by the corresponding group in the regular expression.
[\0] stands for the text matched by the whole regular expression. *)
val replace_first: regexp -> string -> string -> string
(* Same as [global_replace], except that only the first substring
matching the regular expression is replaced. *)
val global_substitute: regexp -> (string -> string) -> string -> string
(* [global_substitute regexp subst s] returns a string identical
to [s], except that all substrings of [s] that match [regexp]
have been replaced by the result of function [subst]. The
function [subst] is called once for each matching substring,
and receives [s] (the whole text) as argument. *)
val substitute_first: regexp -> (string -> string) -> string -> string
(* Same as [global_substitute], except that only the first substring
matching the regular expression is replaced. *)
(*** Splitting *)
val split: regexp -> string -> string list
(* [split r s] splits [s] into substrings, taking as delimiters
the substrings that match [r], and returns the list of substrings.
For instance, [split (regexp "[ \t]+") s] splits [s] into
blank-separated words. *)
val bounded_split: regexp -> string -> int -> string list
(* Same as [split], but splits into at most [n] substrings,
where [n] is the extra integer parameter. *)
(*** Extracting substrings *)
val string_before: string -> int -> string
(* [string_before s n] returns the substring of all characters of [s]
that precede position [n] (excluding the character at
position [n]). *)
val string_after: string -> int -> string
(* [string_after s n] returns the substring of all characters of [s]
that follow position [n] (including the character at
position [n]). *)
val first_chars: string -> int -> string
(* [first_chars s n] returns the first [n] characters of [s].
This is the same function as [string_before]. *)
val last_chars: string -> int -> string
(* [last_chars s n] returns the last [n] characters of [s]. *)
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