typescript-to-lua
Version:
A generic TypeScript to Lua transpiler. Write your code in TypeScript and publish Lua!
126 lines • 7.19 kB
JavaScript
;
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
var desc = Object.getOwnPropertyDescriptor(m, k);
if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
desc = { enumerable: true, get: function() { return m[k]; } };
}
Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
return ar;
};
return ownKeys(o);
};
return function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
exports.transformConditionalExpression = void 0;
exports.transformIfStatement = transformIfStatement;
exports.checkOnlyTruthyCondition = checkOnlyTruthyCondition;
const ts = __importStar(require("typescript"));
const lua = __importStar(require("../../LuaAST"));
const preceding_statements_1 = require("../utils/preceding-statements");
const scope_1 = require("../utils/scope");
const block_1 = require("./block");
const typescript_1 = require("../utils/typescript");
const diagnostics_1 = require("../utils/diagnostics");
const CompilerOptions_1 = require("../../CompilerOptions");
function transformProtectedConditionalExpression(context, expression, condition, whenTrue, whenFalse) {
const tempVar = context.createTempNameForNode(expression.condition);
const trueStatements = whenTrue.precedingStatements.concat(lua.createAssignmentStatement(lua.cloneIdentifier(tempVar), whenTrue.result, expression.whenTrue));
const falseStatements = whenFalse.precedingStatements.concat(lua.createAssignmentStatement(lua.cloneIdentifier(tempVar), whenFalse.result, expression.whenFalse));
context.addPrecedingStatements([
lua.createVariableDeclarationStatement(tempVar, undefined, expression.condition),
...condition.precedingStatements,
lua.createIfStatement(condition.result, lua.createBlock(trueStatements, expression.whenTrue), lua.createBlock(falseStatements, expression.whenFalse), expression),
]);
return lua.cloneIdentifier(tempVar);
}
const transformConditionalExpression = (expression, context) => {
if (context.luaTarget === CompilerOptions_1.LuaTarget.Luau) {
// Luau's ternary operator doesn't have these issues
return lua.createConditionalExpression(context.transformExpression(expression.condition), context.transformExpression(expression.whenTrue), context.transformExpression(expression.whenFalse), expression);
}
// Check if we need to add diagnostic about Lua truthiness
checkOnlyTruthyCondition(expression.condition, context);
const condition = (0, preceding_statements_1.transformInPrecedingStatementScope)(context, () => context.transformExpression(expression.condition));
const whenTrue = (0, preceding_statements_1.transformInPrecedingStatementScope)(context, () => context.transformExpression(expression.whenTrue));
const whenFalse = (0, preceding_statements_1.transformInPrecedingStatementScope)(context, () => context.transformExpression(expression.whenFalse));
if (whenTrue.precedingStatements.length > 0 ||
whenFalse.precedingStatements.length > 0 ||
(0, typescript_1.canBeFalsy)(context, context.checker.getTypeAtLocation(expression.whenTrue))) {
return transformProtectedConditionalExpression(context, expression, condition, whenTrue, whenFalse);
}
// condition and v1 or v2
context.addPrecedingStatements(condition.precedingStatements);
const conditionAnd = lua.createBinaryExpression(condition.result, whenTrue.result, lua.SyntaxKind.AndOperator);
return lua.createBinaryExpression(conditionAnd, whenFalse.result, lua.SyntaxKind.OrOperator, expression);
};
exports.transformConditionalExpression = transformConditionalExpression;
function transformIfStatement(statement, context) {
context.pushScope(scope_1.ScopeType.Conditional, statement);
// Check if we need to add diagnostic about Lua truthiness
checkOnlyTruthyCondition(statement.expression, context);
const condition = context.transformExpression(statement.expression);
const statements = (0, scope_1.performHoisting)(context, (0, block_1.transformBlockOrStatement)(context, statement.thenStatement));
context.popScope();
const ifBlock = lua.createBlock(statements);
if (statement.elseStatement) {
if (ts.isIfStatement(statement.elseStatement)) {
const tsElseStatement = statement.elseStatement;
const { precedingStatements, result: elseStatement } = (0, preceding_statements_1.transformInPrecedingStatementScope)(context, () => transformIfStatement(tsElseStatement, context));
// If else-if condition generates preceding statements, we can't use elseif, we have to break it down:
// if conditionA then
// ...
// else
// conditionB's preceding statements
// if conditionB then
// end
// end
if (precedingStatements.length > 0) {
const elseBlock = lua.createBlock([...precedingStatements, elseStatement]);
return lua.createIfStatement(condition, ifBlock, elseBlock);
}
else {
return lua.createIfStatement(condition, ifBlock, elseStatement);
}
}
else {
context.pushScope(scope_1.ScopeType.Conditional, statement);
const elseStatements = (0, scope_1.performHoisting)(context, (0, block_1.transformBlockOrStatement)(context, statement.elseStatement));
context.popScope();
const elseBlock = lua.createBlock(elseStatements);
return lua.createIfStatement(condition, ifBlock, elseBlock);
}
}
return lua.createIfStatement(condition, ifBlock);
}
function checkOnlyTruthyCondition(condition, context) {
if (context.options.strictNullChecks === false)
return; // This check is not valid if everything could implicitly be nil
if (ts.isElementAccessExpression(condition))
return; // Array index could always implicitly return nil
if (!(0, typescript_1.canBeFalsy)(context, context.checker.getTypeAtLocation(condition))) {
context.diagnostics.push((0, diagnostics_1.truthyOnlyConditionalValue)(condition));
}
}
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