Capture transfer uses from array

Author: slevithan

spec/recursion-spec.js

@@ -168,7 +168,7 @@ describe('recursion', () => {
           captureTransfers: new Map([[1, [2]]]),
         })).toEqual({
           pattern: '(a)(?:(a)(?:)?(b))?(b)',
-          captureTransfers: new Map([[1, [4]]]),
+          captureTransfers: new Map([[1, [3, 4]]]),
           hiddenCaptures: [2, 3],
         });
       });
@@ -179,15 +179,15 @@ describe('recursion', () => {
           hiddenCaptures: [4],
         })).toEqual({
           pattern: '()(()(a)()(?:()(a)()(?:)?b)?b)',
-          captureTransfers: new Map([[1, [7]]]),
+          captureTransfers: new Map([[1, [4, 7]]]),
           hiddenCaptures: [4, 6, 7, 8],
         });
         expect(recursion(r`()(a\g<2&R=2>?()(b)())`, {
           captureTransfers: new Map([[1, [4]]]),
           hiddenCaptures: [4],
         })).toEqual({
           pattern: '()(a(?:a(?:)?()(b)())?()(b)())',
-          captureTransfers: new Map([[1, [7]]]),
+          captureTransfers: new Map([[1, [4, 7]]]),
           hiddenCaptures: [7, 3, 4, 5], // unsorted
         });
       });
@@ -197,7 +197,7 @@ describe('recursion', () => {
           captureTransfers: new Map([[1, [3]]]),
         })).toEqual({
           pattern: '((a)(?:(a)(?:)?(b))?(b))',
-          captureTransfers: new Map([[1, [5]]]),
+          captureTransfers: new Map([[1, [4, 5]]]),
           hiddenCaptures: [3, 4],
         });
       });
@@ -208,23 +208,23 @@ describe('recursion', () => {
           captureTransfers: new Map([[1, [3]], [2, [4]]]),
         })).toEqual({
           pattern: '(?<r>(a)(?:(a)(?:)?b)?b) ((a)(?:(a)(?:)?b)?b)',
-          captureTransfers: new Map([[1, [4]], [2, [6]]]),
+          captureTransfers: new Map([[1, [4]], [2, [5, 6]]]),
           hiddenCaptures: [3, 6],
         });
         // Capture in right contents of recursions
         expect(recursion(r`(?<r>a\g<r&R=2>?(b)) (a\g<3&R=2>?(b))`, {
           captureTransfers: new Map([[1, [3]], [2, [4]]]),
         })).toEqual({
           pattern: '(?<r>a(?:a(?:)?(b))?(b)) (a(?:a(?:)?(b))?(b))',
-          captureTransfers: new Map([[1, [4]], [3, [6]]]),
+          captureTransfers: new Map([[1, [4]], [3, [5, 6]]]),
           hiddenCaptures: [2, 5],
         });
         // Capture in left and right contents of recursions
         expect(recursion(r`(?<r>(a)\g<r&R=2>?(b)) ((a)\g<4&R=2>?(b))`, {
           captureTransfers: new Map([[1, [4]], [2, [5]], [3, [6]]]),
         })).toEqual({
           pattern: '(?<r>(a)(?:(a)(?:)?(b))?(b)) ((a)(?:(a)(?:)?(b))?(b))',
-          captureTransfers: new Map([[1, [6]], [2, [8]], [5, [10]]]),
+          captureTransfers: new Map([[1, [6]], [2, [7, 8]], [5, [9, 10]]]),
           hiddenCaptures: [3, 4, 8, 9],
         });
         // Triple recursion with capture transfer to middle (Oniguruma: `\g<a> (?<a>a\g<b>?b) (?<b>c\g<a>?d)`)
@@ -233,7 +233,7 @@ describe('recursion', () => {
           hiddenCaptures: [1, 2, 4, 6],
         })).toEqual({
           pattern: '(a(c(?:a(c(?:)?d)?b)?d)?b) (?<a>a(c(?:a(c(?:)?d)?b)?d)?b) (?<b>c(a(?:c(a(?:)?b)?d)?b)?d)',
-          captureTransfers: new Map([[4, [9]]]),
+          captureTransfers: new Map([[4, [8, 9]]]),
           hiddenCaptures: [1, 2, 5, 8, 3, 6, 9], // unsorted
         });
         // Same as above but with depth 3
@@ -242,7 +242,7 @@ describe('recursion', () => {
           hiddenCaptures: [1, 2, 4, 6],
         })).toEqual({
           pattern: '(a(c(?:a(c(?:a(c(?:)?d)?b)?d)?b)?d)?b) (?<a>a(c(?:a(c(?:a(c(?:)?d)?b)?d)?b)?d)?b) (?<b>c(a(?:c(a(?:c(a(?:)?b)?d)?b)?d)?b)?d)',
-          captureTransfers: new Map([[5, [12]]]),
+          captureTransfers: new Map([[5, [10, 11, 12]]]),
           hiddenCaptures: [1, 2, 6, 10, 3, 4, 7, 8, 11, 12], // unsorted
         });
       });

src/index.js

@@ -326,25 +326,36 @@ function mapCaptureTransfers(captureTransfers, numCapturesPassed, left, reps, nu
   if (captureTransfers.size && numCapturesAddedInExpansion) {
     let numCapturesInLeft = 0;
     forEachUnescaped(left, captureDelim, () => numCapturesInLeft++, Context.DEFAULT);
-    // 0 for global recursion
+    // Is 0 for global recursion
     const recursionDelimCaptureNum = numCapturesPassed - numCapturesInLeft + numAddedHiddenCapturesPreExpansion;
     const newCaptureTransfers = new Map();
     captureTransfers.forEach((from, to) => {
-      if (to > (numCapturesPassed + numAddedHiddenCapturesPreExpansion)) {
-        to += numCapturesAddedInExpansion;
-      }
-      from = from.map(f => {
-        if (f > recursionDelimCaptureNum) {
-          f += (
-            // if the capture is on the left side of the expanded subpattern
-            f <= (recursionDelimCaptureNum + numCapturesInLeft) ?
-              numCapturesInLeft * reps :
-              numCapturesAddedInExpansion
-          );
+      const newTo = to > (numCapturesPassed + numAddedHiddenCapturesPreExpansion) ?
+        to + numCapturesAddedInExpansion :
+        to;
+      const newFrom = [];
+      for (const f of from) {
+        // Before the recursed subpattern
+        if (f <= recursionDelimCaptureNum) {
+          newFrom.push(f);
+        // After the recursed subpattern
+        } else if (f > (recursionDelimCaptureNum + numCapturesAddedInExpansion)) {
+          newFrom.push(f + numCapturesAddedInExpansion);
+        // Within the recursed subpattern, on the left of the recursion token
+        } else if (f <= (recursionDelimCaptureNum + numCapturesInLeft)) {
+          for (let i = 0; i <= reps; i++) {
+            newFrom.push(f + (numCapturesInLeft * i));
+          }
+        // Within the recursed subpattern, on the right of the recursion token
+        } else {
+          const numCapturesInRight = (numCapturesAddedInExpansion - (numCapturesInLeft * reps)) / reps;
+          const numCapturesAddedInLeft = numCapturesInLeft * reps;
+          for (let i = 0; i <= reps; i++) {
+            newFrom.push(f + numCapturesAddedInLeft + (numCapturesInRight * i));
+          }
         }
-        return f;
-      });
-      newCaptureTransfers.set(to, from);
+      }
+      newCaptureTransfers.set(newTo, newFrom);
     });
     return newCaptureTransfers;
   }