@brimdata/zealot/src/zed/types/type-alias.ts

The Javascript Client for Zed Lakes

import * as zjson from "../../zjson"
import {DecodeStream} from "../decode-stream"
import {EncodeStream} from "../encode-stream"
import {Field} from "../values/field"
import {Value} from "../values/types"
import {TypeRecord} from "./type-record"
import {Type} from "./types"

export class TypeAlias implements Type {
  kind = "alias"

  constructor(public name: string, public type: Type) {}

  static stringify(name: string, type: Type) {
    return name + "=(" + type.toString() + ")"
  }

  create(value: zjson.Value, stream: DecodeStream, parent?: Field) {
    let v: Value
    if (this.type instanceof TypeRecord || this.type instanceof TypeAlias) {
      v = this.type.create(value as zjson.RecordValue, stream, parent)
    } else {
      v = this.type.create(value, stream)
    }
    v.type = this // a better way to do this?
    return v
  }

  serialize(stream: EncodeStream): zjson.NoId<zjson.NamedType> {
    return {kind: "named", name: this.name, type: stream.encodeType(this.type)}
  }

  toString() {
    return this.name + "=(" + this.type.toString() + ")"
  }
}