Skip to content

Fixed empty destructuring declarations/assignments in for...of loops #658

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
tomblind merged 5 commits into from
Jul 10, 2019
Merged

Fixed empty destructuring declarations/assignments in for...of loops #658

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
db45a78
Fixed empty destructuring declarations/assignments in for...of loops
tomblind Jul 9, 2019
a4c90e3
consolidated tests
tomblind Jul 10, 2019
011c980
Merge branch 'master' into bugfix/forof-empty-destructuring
tomblind Jul 10, 2019
ef09b45
removing erroneous tab
tomblind Jul 10, 2019
cb634c3
re-ran prettier
tomblind Jul 10, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
72 changes: 49 additions & 23 deletions src/LuaTransformer.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2260,11 +2260,18 @@ export class LuaTransformer {
return tstl.createDoStatement(result, statement);
}

protected transformForOfInitializer(initializer: ts.ForInitializer, expression: tstl.Expression): tstl.Statement {
protected transformForOfInitializer(
initializer: ts.ForInitializer,
expression: tstl.Expression
): tstl.Statement | undefined {
if (ts.isVariableDeclarationList(initializer)) {
// Declaration of new variable
const variableDeclarations = this.transformVariableDeclaration(initializer.declarations[0]);
if (ts.isArrayBindingPattern(initializer.declarations[0].name)) {
if (initializer.declarations[0].name.elements.length === 0) {
// Ignore empty destructuring assignment
return undefined;
}
expression = this.createUnpackCall(expression, initializer);
} else if (ts.isObjectBindingPattern(initializer.declarations[0].name)) {
throw TSTLErrors.UnsupportedObjectDestructuringInForOf(initializer);
Expand All @@ -2284,10 +2291,15 @@ export class LuaTransformer {
// Assignment to existing variable
let variables: tstl.AssignmentLeftHandSideExpression | tstl.AssignmentLeftHandSideExpression[];
if (ts.isArrayLiteralExpression(initializer)) {
expression = this.createUnpackCall(expression, initializer);
variables = initializer.elements.map(e =>
this.transformExpression(e)
) as tstl.AssignmentLeftHandSideExpression[];
if (initializer.elements.length > 0) {
expression = this.createUnpackCall(expression, initializer);
variables = initializer.elements.map(e =>
this.transformExpression(e)
) as tstl.AssignmentLeftHandSideExpression[];
} else {
// Ignore empty destructring assignment
return undefined;
}
} else if (ts.isObjectLiteralExpression(initializer)) {
throw TSTLErrors.UnsupportedObjectDestructuringInForOf(initializer);
} else {
Expand Down Expand Up @@ -2329,14 +2341,20 @@ export class LuaTransformer {
const variables = statement.initializer.declarations[0].name;
if (ts.isArrayBindingPattern(variables) || ts.isObjectBindingPattern(variables)) {
valueVariable = tstl.createIdentifier("____values");
block.statements.unshift(this.transformForOfInitializer(statement.initializer, valueVariable));
const initializer = this.transformForOfInitializer(statement.initializer, valueVariable);
if (initializer) {
block.statements.unshift(initializer);
}
} else {
valueVariable = this.transformIdentifier(variables);
}
} else {
// Assignment to existing variable
valueVariable = tstl.createIdentifier("____value");
block.statements.unshift(this.transformForOfInitializer(statement.initializer, valueVariable));
const initializer = this.transformForOfInitializer(statement.initializer, valueVariable);
if (initializer) {
block.statements.unshift(initializer);
}
}

const ipairsCall = tstl.createCallExpression(tstl.createIdentifier("ipairs"), [
Expand Down Expand Up @@ -2365,14 +2383,14 @@ export class LuaTransformer {
// for ${initializer} in ${iterable} do
const initializerVariable = statement.initializer.declarations[0].name;
if (ts.isArrayBindingPattern(initializerVariable)) {
return tstl.createForInStatement(
block,
this.filterUndefinedAndCast(
initializerVariable.elements.map(e => this.transformArrayBindingElement(e)),
tstl.isIdentifier
),
[luaIterator]
const identifiers = this.filterUndefinedAndCast(
initializerVariable.elements.map(e => this.transformArrayBindingElement(e)),
tstl.isIdentifier
);
if (identifiers.length === 0) {
identifiers.push(tstl.createAnonymousIdentifier());
}
return tstl.createForInStatement(block, identifiers, [luaIterator]);
} else {
// Single variable is not allowed
throw TSTLErrors.UnsupportedNonDestructuringLuaIterator(statement.initializer);
Expand All @@ -2383,13 +2401,17 @@ export class LuaTransformer {
// ${initializer} = ____value0
if (ts.isArrayLiteralExpression(statement.initializer)) {
const tmps = statement.initializer.elements.map((_, i) => tstl.createIdentifier(`____value${i}`));
const assign = tstl.createAssignmentStatement(
statement.initializer.elements.map(
e => this.transformExpression(e) as tstl.AssignmentLeftHandSideExpression
),
tmps
);
block.statements.splice(0, 0, assign);
if (tmps.length > 0) {
const assign = tstl.createAssignmentStatement(
statement.initializer.elements.map(
e => this.transformExpression(e) as tstl.AssignmentLeftHandSideExpression
),
tmps
);
block.statements.splice(0, 0, assign);
} else {
tmps.push(tstl.createAnonymousIdentifier());
}
return tstl.createForInStatement(block, tmps, [luaIterator]);
} else {
// Single variable is not allowed
Expand All @@ -2415,7 +2437,9 @@ export class LuaTransformer {
// local ${initializer} = unpack(____value)
const valueVariable = tstl.createIdentifier("____value");
const initializer = this.transformForOfInitializer(statement.initializer, valueVariable);
block.statements.splice(0, 0, initializer);
if (initializer) {
block.statements.splice(0, 0, initializer);
}
return tstl.createForInStatement(block, [valueVariable], [luaIterator]);
}
}
Expand All @@ -2440,7 +2464,9 @@ export class LuaTransformer {
// local ${initializer} = ____value
const valueVariable = tstl.createIdentifier("____value");
const initializer = this.transformForOfInitializer(statement.initializer, valueVariable);
block.statements.splice(0, 0, initializer);
if (initializer) {
block.statements.splice(0, 0, initializer);
}
return tstl.createForInStatement(
block,
[valueVariable],
Expand Down
75 changes: 75 additions & 0 deletions test/unit/loops.spec.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -754,6 +754,81 @@ test("forof forwarded lua iterator with tupleReturn", () => {
expect(result).toBe("0a1b2c");
});

describe("for...of empty destructuring", () => {
const declareTests = (destructuringPrefix: string) => {
test("array", () => {
const code = `
const arr = [["a"], ["b"], ["c"]];
let i = 0;
for (${destructuringPrefix}[] of arr) {
++i;
}
return i;
`;
expect(util.transpileAndExecute(code)).toBe(3);
});

test("iterable", () => {
const code = `
const iter: Iterable<string[]> = [["a"], ["b"], ["c"]];
let i = 0;
for (${destructuringPrefix}[] of iter) {
++i;
}
return i;
`;
expect(util.transpileAndExecute(code)).toBe(3);
});

test("luaIterator", () => {
const code = `
const arr = [["a"], ["b"], ["c"]];
/** @luaIterator */
interface Iter extends Iterable<string[]> {}
function luaIter(): Iter {
let it = 0;
return (() => arr[it++]) as any;
}
let i = 0;
for (${destructuringPrefix}[] of luaIter()) {
++i;
}
return i;
`;
expect(util.transpileAndExecute(code)).toBe(3);
});

test("luaIterator+tupleReturn", () => {
const code = `
const arr = [["a", "b"], ["c", "d"], ["e", "f"]];
/** @luaIterator */
/** @tupleReturn */
interface Iter extends Iterable<[string, string]> {}
function luaIter(): Iter {
let it = 0;
/** @tupleReturn */
function iter() {
const e = arr[it++];
if (e) {
return e;
}
}
return iter as any;
}
let i = 0;
for (${destructuringPrefix}[] of luaIter()) {
++i;
}
return i;
`;
expect(util.transpileAndExecute(code)).toBe(3);
});
};

describe("declaration", () => declareTests("const "));
describe("assignment", () => declareTests(""));
});

test.each([
"while (a < b) { i++; continue; }",
"do { i++; continue; } while (a < b)",
Expand Down