moss/src/ast/let.ts

import * as AST from '../ast';
import Env, { EnvError } from '../env';

export class Let {
  public bindings: AST.Binding[];
  public children: AST.Node[];

  public constructor(bindings: AST.Binding[], children: AST.Node[]) {
    this.bindings = bindings;
    this.children = children;
  }

  public compile(env: Env, opts: AST.Opts): string | EnvError {
    this.bindings.forEach((binding) => {
      env.set(binding.identifier.name.value, binding.value);
    });

    const children = this.children.map((child) => child.compile(env, opts));
    const childrenError = children.find((node) => node instanceof EnvError);
    if (childrenError instanceof EnvError) return childrenError;

    return children.join(opts.prettyPrint ? '\n' : '');
  }
}