Merge pull request #4 from fink-lang/unfold-accumulator

feat(unfold): have unfold use the last result as accumulator for next  iteration

package.json

@@ -50,6 +50,9 @@
     }
   },
   "dependencies": {
+    "@babel/generator": "^7.8.4",
+    "@babel/traverse": "^7.8.4",
+    "@babel/types": "^7.8.3",
     "@fink/larix": "^1.0.0"
   }
 }

src/index.js

@@ -176,6 +176,7 @@ export const generate = (ast, filename, code)=> {
     filename,
     sourceMaps: true,
     sourceFileName: filename
+    // shouldPrintComment: ()=> true,
   };
 
   const output = babel_gen(new_ast, options, code);

src/transform/__snapshots__/await.test.js.snap

@@ -22,8 +22,8 @@ const a_gen = async function* unfold(curr = 0) {
 
     const $result1 = _do_result;
     _do_result = undefined;
-    if ($result1 === stop) return;
-    if ($result1 !== skip) yield $result1;
+    yield $result1;
+    curr = $result1;
   }
 }();
 

src/transform/__snapshots__/cond.test.js.snap

@@ -25,5 +25,12 @@ if (foo === true) {
 }
 
 const no_else = _do_result2;
-_do_result2 = undefined;"
+_do_result2 = undefined;
+{
+  if (foo) {
+    shrub;
+  } else {
+    null;
+  }
+}"
 `;

src/transform/__snapshots__/map.test.js.snap

@@ -4,16 +4,14 @@ exports[`compiles map 1`] = `
 "(function* map($items1) {
   for (const item of $items1) {
     const $result2 = item * 2;
-    if ($result2 === stop) return;
-    if ($result2 !== skip) yield $result2;
+    yield $result2;
   }
 });
 
 (function* map($items3) {
   for (const item = 123 of $items3) {
     const $result4 = item * 2;
-    if ($result4 === stop) return;
-    if ($result4 !== skip) yield $result4;
+    yield $result4;
   }
 });
 
@@ -22,32 +20,28 @@ exports[`compiles map 1`] = `
     item
   } of $items5) {
     const $result6 = item * 2;
-    if ($result6 === stop) return;
-    if ($result6 !== skip) yield $result6;
+    yield $result6;
   }
 });
 
 (function* map($items7) {
   for (const [x, y] of $items7) {
     const $result8 = x + y;
-    if ($result8 === stop) return;
-    if ($result8 !== skip) yield $result8;
+    yield $result8;
   }
 });
 
 (function* map($items9) {
   for (const item of $items9) {
     const $result10 = [spam + item];
-    if ($result10 === stop) return;
-    if ($result10 !== skip) yield* $result10;
+    yield* $result10;
   }
 });
 
 (function* map($items11) {
   for (const item of $items11) {
     const $result12 = [spam];
-    if ($result12 === stop) return;
-    if ($result12 !== skip) yield* $result12;
+    yield* $result12;
   }
 });"
 `;

src/transform/__snapshots__/unfold.test.js.snap

@@ -4,17 +4,16 @@ exports[`compiles unfold 1`] = `
 "(function* unfold(curr = start) {
   while (true) {
     const $result1 = curr + inc;
-    if ($result1 === stop) return;
-    if ($result1 !== skip) yield $result1;
+    yield $result1;
     curr = curr * 2;
   }
 })();
 
 const count = (start = 0, inc = 1) => function* unfold(curr = start) {
   while (true) {
     const $result2 = curr + inc;
-    if ($result2 === stop) return;
-    if ($result2 !== skip) yield $result2;
+    yield $result2;
+    curr = $result2;
   }
 }();"
 `;

src/transform/cond.test.js

@@ -12,6 +12,8 @@ test('compiles conditional', ()=> {
       no_else = if:
         foo == true: spam
         shrub == 134: ni
+
+      if: foo: shrub
     `)
   ).toMatchSnapshot();
 });

src/transform/js/do-expression.js

@@ -101,14 +101,15 @@ const transform_do_expr = (path)=> {
     parent.node.body = simple(path.get('body'), true);
     replace_with_return(path);
 
+  } else if (parent.isExpressionStatement()) {
+    // this is used e.g. for conditional at the module level
+    parent.replaceWith(path.get('body').node);
+
   } else {
     throw parent.buildCodeFrameError(`Can't convert do-expression`);
   }
 
-  // else if (parent.isExpressionStatement()) {
-  //   parent.replaceWith(path.get('body').node);
-
-  // } else if (parent.isReturnStatement()) {
+  // else if (parent.isReturnStatement()) {
   //   parent.replaceWith(simple(path.get('body'), true));
   //   replace_with_return(path);