1  const {MAX_LENGTH} = require('../internal/constants')
 2  const { re, t } = require('../internal/re')
 3  const SemVer = require('../classes/semver')
 4  
 5  const parseOptions = require('../internal/parse-options')
 6  const parse = (version, options) => {
 7    options = parseOptions(options)
 8  
 9    if (version instanceof SemVer) {
10      return version
11    }
12  
13    if (typeof version !== 'string') {
14      return null
15    }
16  
17    if (version.length > MAX_LENGTH) {
18      return null
19    }
20  
21    const r = options.loose ? re[t.LOOSE] : re[t.FULL]
22    if (!r.test(version)) {
23      return null
24    }
25  
26    try {
27      return new SemVer(version, options)
28    } catch (er) {
29      return null
30    }
31  }
32  
33  module.exports = parse