[reg_exp.h] Regular Expression Evaluation

contents



#include "standard.h"



[reg_exp] implements a regular expression evaluator based on the following regular expression syntax.

Literal

Construction

Character set' Literal ... '
String" Literal ... "
Any character.
Character range Expression .. Expression
( single character expressions )
Subexpression( Expression )
Option[ Expression ]
 Expression ?
Iteration ( 0.. ){ Expression }
 Expression *
Iteration ( 1.. )Expression +
Iteration ( n )Expression Number
Iteration ( n..m )Expression Number, Number
UnionExpression | Expression
DifferenceExpression - Expression
ConcatenationExpression Expression

Types


Reg_T Abstract regular expression evaluation type

Creating & Disposing 

void REG_drop(Reg_T pReg)
removes regular expression evaluator 'pReg' 
Reg_T REG_create
      (
        c_string szRegExp,  long   lLen,
        c_string szCharSet, c_bool bIgnCase
      )
#define REG_CREATE(exp)  REG_create((exp),-1,(c_string)NULL,C_False)
#define IREG_CREATE(exp) REG_create((exp),-1,(c_string)NULL,C_True)
 creates a regular expression evaluator from string 'szRegExp'
'lLen' : -1 or string size in bytes, incl. terminating bytes
'szCharSet': NULL,"" or character set name
( UCS4, UTF-8, MS:CodePage / GNU:iconv-based )
'szCharSet' = NULL,"" --> single byte string
'lLen' = -1 --> null-terminated single byte or utf8 string
RC: evaluator or NULL

c_bool REG_recreate
       (
         Reg_T    pReg,      c_string szRegExp, long lLen,
         c_string szCharSet, c_bool   bIgnCase
       )
#define REG_RECREATE(reg,exp)  REG_recreate((reg),(exp),-1,(c_string)NULL,C_False)
#define IREG_RECREATE(reg,exp) REG_recreate((reg),(exp),-1,(c_string)NULL,C_True)
 updates regular expression evaluator 'pReg'
from string 'szRegExp'
( 'lLen', 'szCharSet' --> see function 'REG_create' )
RC: true <--> OK


Evaluation 

c_string REG_match
         (
           Reg_T    pReg,
           c_string szTxt,  long lTxtLen, c_string szCharSet,
           long*    lPatLen
         )
#define REG_MATCH(reg,txt,len) REG_match((reg),(txt),-1,(c_string)NULL,(len))
 applies regular expression evaluator 'pReg' to string 'szTxt'
( 'lTxtLen', 'szCharSet' --> see function 'REG_create' )
RC: start postion of first matched value in 'szTxt' or NULL
'lPatLen' != NULL --> length of first matched value in bytes