Function execEditLength

compare/output/diff.js:225–268

()

	    // Main worker method. checks all permutations of a given edit length for acceptance.
	    function execEditLength() {
	      for (var diagonalPath = -1 * editLength; diagonalPath <= editLength; diagonalPath += 2) {
	        var basePath = /*istanbul ignore start*/void 0 /*istanbul ignore end*/;
	        var addPath = bestPath[diagonalPath - 1],
	            removePath = bestPath[diagonalPath + 1],
	            _oldPos = (removePath ? removePath.newPos : 0) - diagonalPath;
	        if (addPath) {
	          // No one else is going to attempt to use this value, clear it
	          bestPath[diagonalPath - 1] = undefined;
	        }

	        var canAdd = addPath && addPath.newPos + 1 < newLen,
	            canRemove = removePath && 0 <= _oldPos && _oldPos < oldLen;
	        if (!canAdd && !canRemove) {
	          // If this path is a terminal then prune
	          bestPath[diagonalPath] = undefined;
	          continue;
	        }

	        // Select the diagonal that we want to branch from. We select the prior
	        // path whose position in the new string is the farthest from the origin
	        // and does not pass the bounds of the diff graph
	        if (!canAdd || canRemove && addPath.newPos < removePath.newPos) {
	          basePath = clonePath(removePath);
	          self.pushComponent(basePath.components, undefined, true);
	        } else {
	          basePath = addPath; // No need to clone, we've pulled it from the list
	          basePath.newPos++;
	          self.pushComponent(basePath.components, true, undefined);
	        }

	        _oldPos = self.extractCommon(basePath, newString, oldString, diagonalPath);

	        // If we have hit the end of both strings, then we are done
	        if (basePath.newPos + 1 >= newLen && _oldPos + 1 >= oldLen) {
	          return done(buildValues(self, basePath.components, newString, oldString, self.useLongestToken));
	        } else {
	          // Otherwise track this path as a potential candidate and continue.
	          bestPath[diagonalPath] = basePath;
	        }
	      }

	      editLength++;
	    }

	    // Performs the length of edit iteration. Is a bit fugly as this has to support the
	    // sync and async mode which is never fun. Loops over execEditLength until a value