firescript/src/SourceBuffer.js

class SourceBuffer {
  constructor () {
    this.buffer = []
    this.locationMap = []
    this.line = 1
    this.column = 1
    this.indention = 0
    this.indentionSize = 2
  }

  write (str, defaultValue) {
    if (!str) {
      if (defaultValue) {
        this.write(defaultValue)
      }

      return this
    }

    if (typeof str === 'object') {
      str.compile(this)
      return this
    }

    const lastIndex = str.lastIndexOf('\n')
    if (lastIndex === -1) {
      this.column += str.length
    } else {
      this.column = str.length - lastIndex
      this.line += (str.split('\n').length - 1)
    }

    this.buffer.push(str)
    return this
  }

  writeItem (item) {
    if (item.leadingComments && item.leadingComments.length) {
      this.writeComments(item.leadingComments)
      this.indent()
    }

    item.compile(this)

    if (item.trailingComments && item.trailingComments.length) {
      this.indent()
      this.writeComments(item.trailingComments)
    }
  }

  writeComments (comments, joiner) {
    if (comments && comments.length > 0) {
      comments.forEach((comment, index) => {
        if (index) {
          joiner === undefined ? this.indent() : this.write(joiner)
        }

        this.write(comment)
      })
    }
  }

  nl (num = 1) {
    this.line += num
    this.column = 1

    this.buffer.push('\n'.repeat(num))
    return this
  }

  getLocation () {
    return [ this.line, this.column ]
  }

  getIndent () {
    // console.log('INDENT', this.indention, this.indentionSize, `"${' '.repeat(this.indention * this.indentionSize)}"`)
    return '\n' + ' '.repeat(this.indention * this.indentionSize)
  }

  indent (size, noWrite) {
    size = size || 0
    this.indention += size

    if (!noWrite) {
      this.write(this.getIndent())
    }
  }

  item (node) {
    node.compile(this)
    return this
  }

  loop (arr, joiner = this.getIndent(), fn) {
    if (arr) {
      arr.forEach((item, index) => {
        if (index > 0) {
          this.write(joiner)
        }

        this.writeItem(item)
      })
    }

    return this
  }

  registerItem (origLocation, name) {
    if (origLocation) {
      const map = [
        origLocation.line,
        origLocation.column,
        this.line,
        this.column
      ]

      if (typeof name === 'string') {
        map.push(name)
      }

      this.locationMap.push(map)
    }

    return this
  }

  toString () {
    return this.buffer.join('')
  }

  print () {
    console.log(this.buffer.slice(-5))
  }

  createLocationMap () {
    if (this.locationMap.length === 0) {
      return
    }

    this.write('module.exports.__fsLocationMap = [')
    this.write(this.locationMap.map((item) => {
      const args = item.slice(0, 4)
      if (item[4]) {
        args.push(`'${item[4].replace(/'/g, '\\\'')}'`)
      }

      return `[${args.join(', ')}]`
    }).join(', '))

    this.write('];')
  }
}

module.exports = SourceBuffer