当您有树型模式时，正则表达式无法正常工作

Question

I have this regex:

^(?'IF'[IF\s]{3})(?'CONDICTION'[\w\s\d+=/\.\*-><\(\)]+)(?'THEN'THEN)(?'TRUE'[\w\s\d+=/\.\*-><\(\)]*)(?'ELSE'[\s\w]ELSE[\s|\n])(?<FALSE>[\w\s\d.+\-*/]*)(?<ENDIF>([\s\nENDIF]{6}))

For this expression:

IF 1 = 1 THEN 1 ELSE 3 ENDIF

Works fine, i got this groups:

IF: IF
CONDICTION: 1 = 1 
THEN: THEN
TRUE: 1
ELSE: ELSE 
FALSE: 3
ENDIF: ENDIF

But if I try this expression:

IF 1 = 1 THEN 1 ELSE IF 1 = 2 THEN 3 ELSE 2 ENDIF ENDIF

I got this groups:

IF: IF 
CONDICTION: 1 = 1 THEN 1 ELSE IF 1 = 2 
THEN: THEN
TRUE:  3
ELSE:  ELSE 
FALSE: 2 ENDIF
ENDIF:  ENDIF

But I want this:

IF: IF 
CONDICTION: 1 = 1
THEN: THEN
TRUE:  1
ELSE:  ELSE 
FALSE: IF 1 = 2 THEN 3 ELSE 2 ENDIF
ENDIF:  ENDIF

What regex I need to match this?

Answer 1

You seem that you are on the right track. You have your grammar defined so you need to tokenize your expressions and depending on your grammar parse them. In other words you need to write a parser for your particular needs.

Some useful link :

http://www.dreamincode.net/forums/topic/110782-c-beginner-parser-class-tutorial/

Answer 2

I solved my problem using Irony

I will explain details in blog and will edit this answer!