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					63 lines
				
				1.2 KiB
			
		
		
			
		
	
	
					63 lines
				
				1.2 KiB
			| 
											3 years ago
										 | 'use strict'; | ||
|  | module.exports = balanced; | ||
|  | function balanced(a, b, str) { | ||
|  |   if (a instanceof RegExp) a = maybeMatch(a, str); | ||
|  |   if (b instanceof RegExp) b = maybeMatch(b, str); | ||
|  | 
 | ||
|  |   var r = range(a, b, str); | ||
|  | 
 | ||
|  |   return r && { | ||
|  |     start: r[0], | ||
|  |     end: r[1], | ||
|  |     pre: str.slice(0, r[0]), | ||
|  |     body: str.slice(r[0] + a.length, r[1]), | ||
|  |     post: str.slice(r[1] + b.length) | ||
|  |   }; | ||
|  | } | ||
|  | 
 | ||
|  | function maybeMatch(reg, str) { | ||
|  |   var m = str.match(reg); | ||
|  |   return m ? m[0] : null; | ||
|  | } | ||
|  | 
 | ||
|  | balanced.range = range; | ||
|  | function range(a, b, str) { | ||
|  |   var begs, beg, left, right, result; | ||
|  |   var ai = str.indexOf(a); | ||
|  |   var bi = str.indexOf(b, ai + 1); | ||
|  |   var i = ai; | ||
|  | 
 | ||
|  |   if (ai >= 0 && bi > 0) { | ||
|  |     if(a===b) { | ||
|  |       return [ai, bi]; | ||
|  |     } | ||
|  |     begs = []; | ||
|  |     left = str.length; | ||
|  | 
 | ||
|  |     while (i >= 0 && !result) { | ||
|  |       if (i == ai) { | ||
|  |         begs.push(i); | ||
|  |         ai = str.indexOf(a, i + 1); | ||
|  |       } else if (begs.length == 1) { | ||
|  |         result = [ begs.pop(), bi ]; | ||
|  |       } else { | ||
|  |         beg = begs.pop(); | ||
|  |         if (beg < left) { | ||
|  |           left = beg; | ||
|  |           right = bi; | ||
|  |         } | ||
|  | 
 | ||
|  |         bi = str.indexOf(b, i + 1); | ||
|  |       } | ||
|  | 
 | ||
|  |       i = ai < bi && ai >= 0 ? ai : bi; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (begs.length) { | ||
|  |       result = [ left, right ]; | ||
|  |     } | ||
|  |   } | ||
|  | 
 | ||
|  |   return result; | ||
|  | } |