firescript/src/js-elements/SwitchStatement.js

Firescript transpiler

const JSElement = require('./JSElement')

/**
 * SwitchStatement
 *
 * @class SwitchStatement
 * @extends JSElement
 *
 * interface SwitchStatement {
 *   type: 'SwitchStatement';
 *   discriminant: Expression;
 *   cases: SwitchCase[];
 * }
 */
class SwitchStatement extends JSElement {
  constructor (ast) {
    super(ast)

    this.discriminant = this.createElement(ast.discriminant)
    this.cases = this.createElementList(ast.cases)
  }

  compile (buffer) {
    buffer.registerItem(this.location)

    buffer.write('switch (')
    buffer.write(this.discriminant)
    buffer.write(') {')
    buffer.indent(1)
    buffer.loop(this.cases, '\n' + buffer.getIndent(), this.addBlankLine)
    buffer.indent(-1)
    buffer.write('}')
  }

  addBlankLine (cur, next) {
    if (!next) {
      return false
    }

    return (
      (cur.type === 'SwitchCase' && next.type === 'SwitchCase' && cur.consequent.length > 0)
    )
  }

  toESString (ctx) {
    const indention = ctx.indent(1)
    const cases = ctx.each(this.cases, this.blockHandler, ctx.indent())
    const finalIndention = ctx.indent(-1)

    return this.renderElement(
      'switch (' +
      this.discriminant.toESString(ctx) +
      ') {' +
      indention +
      cases.trim() +
      finalIndention +
      '}'
    )
  }

  blockHandler (str, item, index, arr) {
    if (index + 1 === arr.length || item.consequent.length === 0) {
      return str
    }

    return str
  }
}

module.exports = SwitchStatement