const lexical = require('./lexical.js')
const Syntax = require('./syntax.js')
const assert = require('./util/assert.js')
const _ = require('./util/underscore.js')
var valueRE = new RegExp(`${lexical.value.source}`, 'g')
module.exports = function (options) {
options = _.assign({}, options)
var filters = {}
var _filterInstance = {
render: function (output, scope) {
var args = this.args.map(arg => Syntax.evalValue(arg, scope))
args.unshift(output)
return this.filter.apply(null, args)
},
parse: function (str) {
var match = lexical.filterLine.exec(str)
assert(match, 'illegal filter: ' + str)
var name = match[1]
var argList = match[2] || ''
var filter = filters[name]
if (typeof filter !== 'function') {
if (options.strict_filters) {
throw new TypeError(`undefined filter: ${name}`)
}
this.name = name
this.filter = x => x
this.args = []
return this
}
var args = []
while ((match = valueRE.exec(argList.trim()))) {
var v = match[0]
var re = new RegExp(`${v}\\s*:`, 'g')
re.test(match.input) ? args.push(`'${v}'`) : args.push(v)
}
this.name = name
this.filter = filter
this.args = args
return this
}
}
function construct (str) {
var instance = Object.create(_filterInstance)
return instance.parse(str)
}
function register (name, filter) {
filters[name] = filter
}
function clear () {
filters = {}
}
return {
construct, register, clear
}
}
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