Visitor Class — react Architecture

Source Code

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ExtractScopeDeclarationsFromDestructuring.ts lines 106–152

class Visitor extends ReactiveFunctionTransform<State> {
  override visitScope(scope: ReactiveScopeBlock, state: State): void {
    for (const [, declaration] of scope.scope.declarations) {
      state.declared.add(declaration.identifier.declarationId);
    }
    this.traverseScope(scope, state);
  }

  override transformInstruction(
    instruction: ReactiveInstruction,
    state: State,
  ): Transformed<ReactiveStatement> {
    this.visitInstruction(instruction, state);

    let instructionsToProcess: Array<ReactiveInstruction> = [instruction];
    let result: Transformed<ReactiveStatement> = {kind: 'keep'};

    if (instruction.value.kind === 'Destructure') {
      const transformed = transformDestructuring(
        state,
        instruction,
        instruction.value,
      );
      if (transformed) {
        instructionsToProcess = transformed;
        result = {
          kind: 'replace-many',
          value: transformed.map(instruction => ({
            kind: 'instruction',
            instruction,
          })),
        };
      }
    }

    // Update state.declared with declarations from the instruction(s)
    for (const instr of instructionsToProcess) {
      for (const [place, kind] of eachInstructionLValueWithKind(instr)) {
        if (kind !== InstructionKind.Reassign) {
          state.declared.add(place.identifier.declarationId);
        }
      }
    }

    return result;
  }
}