OwlCyberSecurity - MANAGER

Edit File: TokenStream.js

const SYMBOL_MATCH = 'SYMBOL_MATCH'

export default class TokenStream {
  constructor(nodes, parent) {
    this.index = 0
    this.nodes = nodes
    this.functionName = parent != null ? parent.value : null
    this.lastValue = null
    this.rewindIndex = -1
  }

hasTokens() {
    return this.index <= this.nodes.length - 1
  }

[SYMBOL_MATCH](...tokenDescriptors) {
    if (!this.hasTokens()) return null

const node = this.nodes[this.index]

for (let i = 0; i < tokenDescriptors.length; i += 1) {
      const tokenDescriptor = tokenDescriptors[i]
      const value = tokenDescriptor(node)
      if (value !== null) {
        this.index += 1
        this.lastValue = value
        return value
      }
    }

return null
  }

matches(...tokenDescriptors) {
    return this[SYMBOL_MATCH](...tokenDescriptors) !== null
  }

expect(...tokenDescriptors) {
    const value = this[SYMBOL_MATCH](...tokenDescriptors)
    return value !== null ? value : this.throw()
  }

matchesFunction() {
    const node = this.nodes[this.index]
    if (node.type !== 'function') return null
    const value = new TokenStream(node.nodes, node)
    this.index += 1
    this.lastValue = null
    return value
  }

expectFunction() {
    const value = this.matchesFunction()
    return value !== null ? value : this.throw()
  }

expectEmpty() {
    if (this.hasTokens()) this.throw()
  }

throw() {
    throw new Error(`Unexpected token type: ${this.nodes[this.index].type}`)
  }

saveRewindPoint() {
    this.rewindIndex = this.index
  }

rewind() {
    if (this.rewindIndex === -1) throw new Error('Internal error')
    this.index = this.rewindIndex
    this.lastValue = null
  }
}