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Clean up transformations after #714.

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Since now we have runtime helper, we don't need
expression -> statement conversions anymore.
This commit is contained in:
Ingvar Stepanyan
2015-02-08 10:15:25 +02:00
parent cde988f99f
commit 91362f80b1
7 changed files with 23 additions and 82 deletions
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60
lib/6to5/transformation/transformers/es6/tail-call.js
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@@ -12,51 +12,21 @@ function transformExpression(node, scope, state) {
return (function subTransform(node) {
switch (node.type) {
case "ConditionalExpression":
var callConsequent = subTransform(node.consequent);
var callAlternate = subTransform(node.alternate);
if (!callConsequent && !callAlternate) {
return;
}
// if ternary operator had tail recursion in value, convert to optimized if-statement
node.type = "IfStatement";
node.consequent = callConsequent ? t.toBlock(callConsequent) : returnBlock(node.consequent);
if (callAlternate) {
node.alternate = t.isIfStatement(callAlternate) ? callAlternate : t.toBlock(callAlternate);
} else {
node.alternate = returnBlock(node.alternate);
}
return [node];
// any value of ternary operator can be final one
subTransform(node.consequent);
subTransform(node.alternate);
break;
case "LogicalExpression":
// only call in right-value of can be optimized
var callRight = subTransform(node.right);
if (!callRight) {
return;
}
var test = state.wrapSideEffect(node.left);
if (node.operator === "&&") {
test.expr = t.unaryExpression("!", test.expr);
}
return [t.ifStatement(test.expr, returnBlock(test.ref))].concat(callRight);
// only right expression can be final and so optimized
subTransform(node.right);
break;
case "SequenceExpression":
// only last element of sequence can be optimized
var seq = node.expressions;
// only last element can be optimized
var lastCall = subTransform(seq[seq.length - 1]);
if (!lastCall) {
return;
}
// remove converted expression from sequence
// and convert to regular expression if needed
if (--seq.length === 1) {
node = seq[0];
}
return [t.expressionStatement(node)].concat(lastCall);
subTransform(seq[seq.length - 1]);
break;
case "CallExpression":
var callee = node.callee, thisBinding;
@@ -77,10 +47,9 @@ function transformExpression(node, scope, state) {
args.push(thisBinding);
}
return [t.returnStatement(t.callExpression(
state.getHelperRef(),
args
))];
node.callee = state.getHelperRef();
node.arguments = args;
break;
}
})(node);
}
@@ -92,7 +61,8 @@ var functionChildrenVisitor = {
this.skip();
// transform return argument into statement if
// it contains tail recursion
return transformExpression(node.argument, scope, state);
transformExpression(node.argument, scope, state);
return;
} else if (t.isFunction(node)) {
return this.skip();
} else if (t.isTryStatement(parent)) {