challenge-algorithms-v2.0-D.../node_modules/browserslist/parse.js

79 lines
1.7 KiB
JavaScript

var AND_REGEXP = /^\s+and\s+(.*)/i
var OR_REGEXP = /^(?:,\s*|\s+or\s+)(.*)/i
function flatten(array) {
if (!Array.isArray(array)) return [array]
return array.reduce(function (a, b) {
return a.concat(flatten(b))
}, [])
}
function find(string, predicate) {
for (var n = 1, max = string.length; n <= max; n++) {
var parsed = string.substr(-n, n)
if (predicate(parsed, n, max)) {
return string.slice(0, -n)
}
}
return ''
}
function matchQuery(all, query) {
var node = { query: query }
if (query.indexOf('not ') === 0) {
node.not = true
query = query.slice(4)
}
for (var name in all) {
var type = all[name]
var match = query.match(type.regexp)
if (match) {
node.type = name
for (var i = 0; i < type.matches.length; i++) {
node[type.matches[i]] = match[i + 1]
}
return node
}
}
node.type = 'unknown'
return node
}
function matchBlock(all, string, qs) {
var node
return find(string, function (parsed, n, max) {
if (AND_REGEXP.test(parsed)) {
node = matchQuery(all, parsed.match(AND_REGEXP)[1])
node.compose = 'and'
qs.unshift(node)
return true
} else if (OR_REGEXP.test(parsed)) {
node = matchQuery(all, parsed.match(OR_REGEXP)[1])
node.compose = 'or'
qs.unshift(node)
return true
} else if (n === max) {
node = matchQuery(all, parsed.trim())
node.compose = 'or'
qs.unshift(node)
return true
}
return false
})
}
module.exports = function parse(all, queries) {
if (!Array.isArray(queries)) queries = [queries]
return flatten(
queries.map(function (block) {
var qs = []
do {
block = matchBlock(all, block, qs)
} while (block)
return qs
})
)
}