function getLocalName(node) {
  switch (node.type) {
    case 'ElementNode':
      // unfortunately the ElementNode stores `tag` as a string
      // if that changes in glimmer-vm this will need to be updated
      return node.tag.split('.')[0];

    case 'SubExpression':
    case 'MustacheStatement':
    case 'BlockStatement':
      return getLocalName(node.path);

    case 'UndefinedLiteral':
    case 'NullLiteral':
    case 'BooleanLiteral':
    case 'StringLiteral':
    case 'NumberLiteral':
    case 'TextNode':
    case 'Template':
    case 'Block':
    case 'CommentStatement':
    case 'MustacheCommentStatement':
    case 'PartialStatement':
    case 'ElementModifierStatement':
    case 'AttrNode':
    case 'ConcatStatement':
    case 'Program':
    case 'Hash':
    case 'HashPair':
      return undefined;

    case 'PathExpression':
    default:
      return node.parts.length ? node.parts[0] : undefined;
  }
}

function getLocals(node) {
  switch (node.type) {
    case 'ElementNode':
    case 'Program':
    case 'Block':
    case 'Template':
      return node.blockParams;

    case 'BlockStatement':
      return node.program.blockParams;

    default:
      return undefined;
  }
}

export class TransformScope {
  constructor(locals) {
    this.locals = locals;
    this.hasPartial = false;
    this.usedLocals = {};

    for (const local of locals) {
      this.usedLocals[local] = false;
    }
  }

  child(node) {
    let locals = getLocals(node);
    return locals ? new ChildTransformScope(locals, this) : this;
  }

  usePartial() {
    this.hasPartial = true;
  }

}
export default class RootTransformScope extends TransformScope {
  constructor(node) {
    var _a;

    let locals = (_a = getLocals(node)) !== null && _a !== void 0 ? _a : [];
    super(locals);
  }

  useLocal(node) {
    let name = getLocalName(node);

    if (name && name in this.usedLocals) {
      this.usedLocals[name] = true;
    }
  }

  isLocal(name) {
    return this.locals.indexOf(name) !== -1;
  }

  currentUnusedLocals() {
    if (!this.hasPartial && this.locals.length > 0) {
      return this.locals.filter(local => !this.usedLocals[local]);
    }

    return false;
  }

}

class ChildTransformScope extends TransformScope {
  constructor(locals, parent) {
    super(locals);
    this.parent = parent;
  }

  useLocal(node) {
    let name = getLocalName(node);

    if (name && name in this.usedLocals) {
      this.usedLocals[name] = true;
    } else {
      this.parent.useLocal(node);
    }
  }

  isLocal(name) {
    return this.locals.indexOf(name) !== -1 || this.parent.isLocal(name);
  }

  currentUnusedLocals() {
    if (!this.hasPartial && this.locals.length > 0) {
      // We only care about the last local, because if it is used then it implies
      // usage of the others (specifically when in a child block, |foo bar|)
      if (!this.usedLocals[this.locals[this.locals.length - 1]]) {
        return [this.locals[this.locals.length - 1]];
      }
    }

    return false;
  }

}
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node.parts[0] : undefined;\n  }\n}\n\nfunction getLocals(node: ASTv1.Node): string[] | undefined {\n  switch (node.type) {\n    case 'ElementNode':\n    case 'Program':\n    case 'Block':\n    case 'Template':\n      return node.blockParams;\n\n    case 'BlockStatement':\n      return node.program.blockParams;\n\n    default:\n      return undefined;\n  }\n}\n\nexport abstract class TransformScope {\n  hasPartial = false;\n  usedLocals: { [key: string]: boolean } = {};\n\n  constructor(protected locals: string[]) {\n    for (const local of locals) {\n      this.usedLocals[local] = false;\n    }\n  }\n\n  child(node: ASTv1.Node): TransformScope {\n    let locals = getLocals(node);\n\n    return locals ? new ChildTransformScope(locals, this) : this;\n  }\n\n  usePartial(): void {\n    this.hasPartial = true;\n  }\n\n  abstract isLocal(name: string): boolean;\n  abstract useLocal(node: ASTv1.Node): void;\n  abstract currentUnusedLocals(): string[] | false;\n}\n\nexport default class RootTransformScope extends TransformScope {\n  constructor(node: ASTv1.Node) {\n    let locals = getLocals(node) ?? [];\n\n    super(locals);\n  }\n\n  useLocal(node: ASTv1.Node): void {\n    let name = getLocalName(node);\n\n    if (name && name in this.usedLocals) {\n      this.usedLocals[name] = true;\n    }\n  }\n\n  isLocal(name: string): boolean {\n    return this.locals.indexOf(name) !== -1;\n  }\n\n  currentUnusedLocals(): string[] | false {\n    if (!this.hasPartial && this.locals.length > 0) {\n      return this.locals.filter((local) => !this.usedLocals[local]);\n    }\n\n    return false;\n  }\n}\n\nclass ChildTransformScope extends TransformScope {\n  constructor(locals: string[], private parent: TransformScope) {\n    super(locals);\n  }\n\n  useLocal(node: ASTv1.Node): void {\n    let name = getLocalName(node);\n\n    if (name && name in this.usedLocals) {\n      this.usedLocals[name] = true;\n    } else {\n      this.parent.useLocal(node);\n    }\n  }\n\n  isLocal(name: string): boolean {\n    return this.locals.indexOf(name) !== -1 || this.parent.isLocal(name);\n  }\n\n  currentUnusedLocals(): string[] | false {\n    if (!this.hasPartial && this.locals.length > 0) {\n      // We only care about the last local, because if it is used then it implies\n      // usage of the others (specifically when in a child block, |foo bar|)\n      if (!this.usedLocals[this.locals[this.locals.length - 1]]) {\n        return [this.locals[this.locals.length - 1]];\n      }\n    }\n\n    return false;\n  }\n}\n"],"sourceRoot":""}