Class TcbForLoopTrackTranslator

packages/compiler/src/typecheck/ops/for_block.ts:71–108

}

export class TcbForLoopTrackTranslator extends TcbExpressionTranslator {
  private allowedVariables: Set<Variable>;

  constructor(
    tcb: Context,
    scope: Scope,
    private block: ForLoopBlock,
  ) {
    super(tcb, scope);

    // Tracking expressions are only allowed to read the `$index`,
    // the item and properties off the component instance.
    this.allowedVariables = new Set([block.item]);
    for (const variable of block.contextVariables) {
      if (variable.value === '$index') {
        this.allowedVariables.add(variable);
      }
    }
  }

  protected override resolve(ast: AST): TcbExpr | null {
    if (
      ast instanceof PropertyRead &&
      (ast.receiver instanceof ImplicitReceiver || ast.receiver instanceof ThisReceiver)
    ) {
      const target = this.tcb.boundTarget.getExpressionTarget(ast);

      if (
        target !== null &&
        (!(target instanceof Variable) || !this.allowedVariables.has(target))
      ) {
        this.tcb.oobRecorder.illegalForLoopTrackAccess(this.tcb.id, this.block, ast);
      }
    }

    return super.resolve(ast);
  }
}