FM / spdx-expression-parse

/snap/node/11691/lib/node_modules/npm/node_modules/spdx-expression-parse/

/snap/node/11691/lib/node_modules/npm/node_modules/spdx-expression-parse

Name	Size	Mode	Actions
AUTHORS	203	0644	edit dl rm
index.js	143	0644	edit dl rm
LICENSE	1111	0644	edit dl rm
package.json	912	0644	edit dl rm
parse.js	2901	0644	edit dl rm
scan.js	2774	0644	edit dl rm

Edit: /snap/node/11691/lib/node_modules/npm/node_modules/spdx-expression-parse/parse.js (2901B)

'use strict'

// The ABNF grammar in the spec is totally ambiguous.
//
// This parser follows the operator precedence defined in the
// `Order of Precedence and Parentheses` section.

module.exports = function (tokens) {
  var index = 0

function hasMore () {
    return index < tokens.length
  }

function token () {
    return hasMore() ? tokens[index] : null
  }

function next () {
    if (!hasMore()) {
      throw new Error()
    }
    index++
  }

function parseOperator (operator) {
    var t = token()
    if (t && t.type === 'OPERATOR' && operator === t.string) {
      next()
      return t.string
    }
  }

function parseWith () {
    if (parseOperator('WITH')) {
      var t = token()
      if (t && t.type === 'EXCEPTION') {
        next()
        return t.string
      }
      throw new Error('Expected exception after `WITH`')
    }
  }

function parseLicenseRef () {
    // TODO: Actually, everything is concatenated into one string
    // for backward-compatibility but it could be better to return
    // a nice structure.
    var begin = index
    var string = ''
    var t = token()
    if (t.type === 'DOCUMENTREF') {
      next()
      string += 'DocumentRef-' + t.string + ':'
      if (!parseOperator(':')) {
        throw new Error('Expected `:` after `DocumentRef-...`')
      }
    }
    t = token()
    if (t.type === 'LICENSEREF') {
      next()
      string += 'LicenseRef-' + t.string
      return { license: string }
    }
    index = begin
  }

function parseLicense () {
    var t = token()
    if (t && t.type === 'LICENSE') {
      next()
      var node = { license: t.string }
      if (parseOperator('+')) {
        node.plus = true
      }
      var exception = parseWith()
      if (exception) {
        node.exception = exception
      }
      return node
    }
  }

function parseParenthesizedExpression () {
    var left = parseOperator('(')
    if (!left) {
      return
    }

var expr = parseExpression()

if (!parseOperator(')')) {
      throw new Error('Expected `)`')
    }

return expr
  }

function parseAtom () {
    return (
      parseParenthesizedExpression() ||
      parseLicenseRef() ||
      parseLicense()
    )
  }

function makeBinaryOpParser (operator, nextParser) {
    return function parseBinaryOp () {
      var left = nextParser()
      if (!left) {
        return
      }

if (!parseOperator(operator)) {
        return left
      }

var right = parseBinaryOp()
      if (!right) {
        throw new Error('Expected expression')
      }
      return {
        left: left,
        conjunction: operator.toLowerCase(),
        right: right
      }
    }
  }

var parseAnd = makeBinaryOpParser('AND', parseAtom)
  var parseExpression = makeBinaryOpParser('OR', parseAnd)

var node = parseExpression()
  if (!node || hasMore()) {
    throw new Error('Syntax error')
  }
  return node
}

cmd: