ts2dart/lib/statement.ts

Transpile TypeScript code to Dart

import * as ts from 'typescript';
import * as base from './base';
import {Transpiler} from './main';

type ClassLike = ts.ClassDeclaration | ts.InterfaceDeclaration;

export default class StatementTranspiler extends base.TranspilerBase {
  constructor(tr: Transpiler) { super(tr); }

  visitNode(node: ts.Node): boolean {
    switch (node.kind) {
      case ts.SyntaxKind.EmptyStatement:
        this.emit(';');
        break;
      case ts.SyntaxKind.ReturnStatement:
        let retStmt = <ts.ReturnStatement>node;
        this.emit('return');
        if (retStmt.expression) this.visit(retStmt.expression);
        this.emit(';');
        break;
      case ts.SyntaxKind.BreakStatement:
      case ts.SyntaxKind.ContinueStatement:
        let breakContinue = <ts.BreakOrContinueStatement>node;
        this.emit(breakContinue.kind === ts.SyntaxKind.BreakStatement ? 'break' : 'continue');
        if (breakContinue.label) this.visit(breakContinue.label);
        this.emit(';');
        break;
      case ts.SyntaxKind.VariableStatement:
        let variableStmt = <ts.VariableStatement>node;
        this.visit(variableStmt.declarationList);
        this.emit(';');
        break;
      case ts.SyntaxKind.ExpressionStatement:
        let expr = <ts.ExpressionStatement>node;
        this.visit(expr.expression);
        this.emit(';');
        break;
      case ts.SyntaxKind.SwitchStatement:
        let switchStmt = <ts.SwitchStatement>node;
        this.emit('switch (');
        this.visit(switchStmt.expression);
        this.emit(')');
        this.visit(switchStmt.caseBlock);
        break;
      case ts.SyntaxKind.CaseBlock:
        this.emit('{');
        this.visitEach((<ts.CaseBlock>node).clauses);
        this.emit('}');
        break;
      case ts.SyntaxKind.CaseClause:
        let caseClause = <ts.CaseClause>node;
        this.emit('case');
        this.visit(caseClause.expression);
        this.emit(':');
        this.visitEach(caseClause.statements);
        break;
      case ts.SyntaxKind.DefaultClause:
        this.emit('default :');
        this.visitEach((<ts.DefaultClause>node).statements);
        break;
      case ts.SyntaxKind.IfStatement:
        let ifStmt = <ts.IfStatement>node;
        this.emit('if (');
        this.visit(ifStmt.expression);
        this.emit(')');
        this.visit(ifStmt.thenStatement);
        if (ifStmt.elseStatement) {
          this.emit('else');
          this.visit(ifStmt.elseStatement);
        }
        break;
      case ts.SyntaxKind.ForStatement:
        let forStmt = <ts.ForStatement>node;
        this.emit('for (');
        if (forStmt.initializer) this.visit(forStmt.initializer);
        this.emit(';');
        if (forStmt.condition) this.visit(forStmt.condition);
        this.emit(';');
        if (forStmt.incrementor) this.visit(forStmt.incrementor);
        this.emit(')');
        this.visit(forStmt.statement);
        break;
      case ts.SyntaxKind.ForInStatement:
        // TODO(martinprobst): Dart's for-in loops actually have different semantics, they are more
        // like for-of loops, iterating over collections.
        let forInStmt = <ts.ForInStatement>node;
        this.emit('for (');
        if (forInStmt.initializer) this.visit(forInStmt.initializer);
        this.emit('in');
        this.visit(forInStmt.expression);
        this.emit(')');
        this.visit(forInStmt.statement);
        break;
      case ts.SyntaxKind.ForOfStatement:
        let forOfStmt = <ts.ForOfStatement>node;
        this.emit('for (');
        if (forOfStmt.initializer) this.visit(forOfStmt.initializer);
        this.emit('in');
        this.visit(forOfStmt.expression);
        this.emit(')');
        this.visit(forOfStmt.statement);
        break;
      case ts.SyntaxKind.WhileStatement:
        let whileStmt = <ts.WhileStatement>node;
        this.emit('while (');
        this.visit(whileStmt.expression);
        this.emit(')');
        this.visit(whileStmt.statement);
        break;
      case ts.SyntaxKind.DoStatement:
        let doStmt = <ts.DoStatement>node;
        this.emit('do');
        this.visit(doStmt.statement);
        this.emit('while (');
        this.visit(doStmt.expression);
        this.emit(') ;');
        break;

      case ts.SyntaxKind.ThrowStatement:
        let throwStmt = <ts.ThrowStatement>node;
        let surroundingCatchClause = this.getAncestor(throwStmt, ts.SyntaxKind.CatchClause);
        if (surroundingCatchClause) {
          let ref = (<ts.CatchClause>surroundingCatchClause).variableDeclaration;
          if (ref.getText() === throwStmt.expression.getText()) {
            this.emit('rethrow');
            this.emit(';');
            break;
          }
        }

        this.emit('throw');
        this.visit(throwStmt.expression);
        this.emit(';');
        break;
      case ts.SyntaxKind.TryStatement:
        let tryStmt = <ts.TryStatement>node;
        this.emit('try');
        this.visit(tryStmt.tryBlock);
        if (tryStmt.catchClause) {
          this.visit(tryStmt.catchClause);
        }
        if (tryStmt.finallyBlock) {
          this.emit('finally');
          this.visit(tryStmt.finallyBlock);
        }
        break;
      case ts.SyntaxKind.CatchClause:
        let ctch = <ts.CatchClause>node;
        if (ctch.variableDeclaration.type) {
          this.emit('on');
          this.visit(ctch.variableDeclaration.type);
        }
        this.emit('catch');
        this.emit('(');
        this.visit(ctch.variableDeclaration.name);
        this.emit(',');
        this.visit(ctch.variableDeclaration.name);
        this.emitNoSpace('_stack');
        this.emit(')');
        this.visit(ctch.block);
        break;

      case ts.SyntaxKind.Block:
        this.emit('{');
        this.visitEach((<ts.Block>node).statements);
        this.emit('}');
        break;
      default:
        return false;
    }
    return true;
  }
}