13.14 Regexp Interface

ORIGIN 'betaenv';
LIB_DEF 'regexp' '../lib';
BODY 'private/regexplib';
(*
 * COPYRIGHT
 *       Copyright (C) Mjolner Informatics, 1992-96
 *       All rights reserved.
 *)
--- textlib: attributes ---
regexp_operation:
  (* generic superpattern for all regexp text operations:
   *     regexp_match, regexp_search, regexp_replace,
   *     regexp_replace_literally.
   * regexp_string: text string containing the regexp.
   * start: start position for match in THIS(text).  
   *        Default: pos
   * limit: end position for match in THIS(text).  
   *        Default: length
   * posToMatchEnd: if true, move THIS(text).pos to the end of the
   *                matched substring.  
   *        Default: false
   * regs: structure for getting access to the matched substring.
   * noMatch: invoked if no matches are found.
   * regexpError: is invoked if syntax error occurs in the specified
   * regexp.
   * 
   * value: true, if any match is found.
   *)
  (# regexp_string: ^text;
     start:< integerObject(# do pos -> value; INNER #);
     limit:< integerObject(# do length -> value; INNER #);
     posToMatchEnd:< booleanObject;
     regs: @regexp_registers;
     noMatch:< Notification;
     regexpError:< Exception(# do 'Syntax error in regular expression'->msg #);
     value: @boolean;
     private: @(* private *)...
  enter (#
        enter regexp_string[]
        do ...
        #)
  do INNER regexp_operation
  exit value
  #);

regexp_match: regexp_operation
(* Takes a regexp as enter parameter (in the form of a reference to a
 * text, containing the regexp.  Matches THIS(text) against the
 * regexp.  INNER is executed if THIS(text) matches the regexp, and
 * the virtual notification noMatch is invoked otherwise.  Returns
 * true if a match is found, false otherwise.  The regexp must be
 * found starting at the current position of THIS(text).
 *)
(# do ... #);

regexp_search: regexp_operation
(* Like regexp_match, except that the match is allowed to be found
 * anywhere between the current position and the end of THIS(text).
 *)
(# do ... #);

regexp_replace: regexp_search
(* Like regexp_search, except that it takes a second enter parameter,
 * replace_string.  Regexp_replace searches for the regexp, and
 * replaces the matched substring of THIS(text) with the replacement
 * string.  The replacement string may contain \0, \1, ..., \9,
 * representing the substring matched by the i'th parenthesis in the
 * regexp.  \0 represents the entire substring matched.  INNER is
 * executed after the replace have taken place.
 *)
(# replace_string: ^text;
enter replace_string[]
do ...
#);

regexp_replace_global:
  (* replaces all occurences of m with r in THIS(text) using
   * regexp_replace, starting from THIS(text).pos.
   *)
  (# m,r: ^Text; more: @boolean;
     replaceOp: @regexp_replace
     (# noMatch:: (# do false->more #);
        posToMatchEnd:: (# do true->value #)
     #);
  enter (m[],r[])
  do true->more;
     (m[],r[])->replaceOp;
     loop:
       (if more and not eos then
           replaceOp;
           restart loop
       if)
  #);

regexp_replace_literally: regexp_search
(* Like regexp_replace, except that the replacement string is taken
 * literally (i.e \0, \1, etc. are not substituted with any matched
 * substrings).
 *)
(# replace_string: ^text
enter replace_string[]
do ...
#);

regexp_replace_literally_global:
  (* replaces all occurences of m with r in THIS(text) using
   * regexp_replace_literally, starting from THIS(text).pos.
   *)
  (# m,r: ^Text; more: @boolean;
     replaceOp: @regexp_replace_literally
     (# noMatch:: (# do false->more #);
        posToMatchEnd:: (# do true->value #)
     #);
  enter (m[],r[])
  do true->more;
     (m[],r[])->replaceOp;
     loop:
       (if more and not eos then
           replaceOp;
           restart loop
       if)
  #);

--- lib: attributes ---
regexp_numberOfRegisters: (# exit 10 #);

regexp_registers: Cstruct
  (* Structure for accessing the substrings matched by some regexp. *)
  (# getRegisterValue:
       (# regNr, value: @integer;
          pos:< integerValue;
          thePos: @pos (* private: for efficiency *)
       enter regNr
       do ...
       exit value
       #);
     start: @getRegisterValue
       (# pos::< (# do 0 -> value #) #);
     end: @getRegisterValue
       (# pos::< (# do 40 -> value #) #);
     byteSize::< (* private *) (# do regexp_numberOfRegisters*2*4 -> value #)
  #)