/*!
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* media-typer
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* Copyright(c) 2014 Douglas Christopher Wilson
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* MIT Licensed
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*/
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/**
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* RegExp to match *( ";" parameter ) in RFC 2616 sec 3.7
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*
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* parameter = token "=" ( token | quoted-string )
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* token = 1*<any CHAR except CTLs or separators>
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* separators = "(" | ")" | "<" | ">" | "@"
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* | "," | ";" | ":" | "\" | <">
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* | "/" | "[" | "]" | "?" | "="
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* | "{" | "}" | SP | HT
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* quoted-string = ( <"> *(qdtext | quoted-pair ) <"> )
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* qdtext = <any TEXT except <">>
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* quoted-pair = "\" CHAR
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* CHAR = <any US-ASCII character (octets 0 - 127)>
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* TEXT = <any OCTET except CTLs, but including LWS>
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* LWS = [CRLF] 1*( SP | HT )
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* CRLF = CR LF
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* CR = <US-ASCII CR, carriage return (13)>
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* LF = <US-ASCII LF, linefeed (10)>
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* SP = <US-ASCII SP, space (32)>
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* SHT = <US-ASCII HT, horizontal-tab (9)>
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* CTL = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
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* OCTET = <any 8-bit sequence of data>
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*/
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var paramRegExp = /; *([!#$%&'\*\+\-\.0-9A-Z\^_`a-z\|~]+) *= *("(?:[ !\u0023-\u005b\u005d-\u007e\u0080-\u00ff]|\\[\u0020-\u007e])*"|[!#$%&'\*\+\-\.0-9A-Z\^_`a-z\|~]+) */g;
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var textRegExp = /^[\u0020-\u007e\u0080-\u00ff]+$/
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var tokenRegExp = /^[!#$%&'\*\+\-\.0-9A-Z\^_`a-z\|~]+$/
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/**
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* RegExp to match quoted-pair in RFC 2616
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*
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* quoted-pair = "\" CHAR
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* CHAR = <any US-ASCII character (octets 0 - 127)>
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*/
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var qescRegExp = /\\([\u0000-\u007f])/g;
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/**
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* RegExp to match chars that must be quoted-pair in RFC 2616
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*/
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var quoteRegExp = /([\\"])/g;
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/**
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* RegExp to match type in RFC 6838
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*
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* type-name = restricted-name
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* subtype-name = restricted-name
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* restricted-name = restricted-name-first *126restricted-name-chars
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* restricted-name-first = ALPHA / DIGIT
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* restricted-name-chars = ALPHA / DIGIT / "!" / "#" /
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* "$" / "&" / "-" / "^" / "_"
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* restricted-name-chars =/ "." ; Characters before first dot always
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* ; specify a facet name
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* restricted-name-chars =/ "+" ; Characters after last plus always
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* ; specify a structured syntax suffix
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* ALPHA = %x41-5A / %x61-7A ; A-Z / a-z
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* DIGIT = %x30-39 ; 0-9
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*/
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var subtypeNameRegExp = /^[A-Za-z0-9][A-Za-z0-9!#$&^_.-]{0,126}$/
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var typeNameRegExp = /^[A-Za-z0-9][A-Za-z0-9!#$&^_-]{0,126}$/
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var typeRegExp = /^ *([A-Za-z0-9][A-Za-z0-9!#$&^_-]{0,126})\/([A-Za-z0-9][A-Za-z0-9!#$&^_.+-]{0,126}) *$/;
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/**
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* Module exports.
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*/
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exports.format = format
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exports.parse = parse
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/**
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* Format object to media type.
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*
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* @param {object} obj
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* @return {string}
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* @api public
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*/
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function format(obj) {
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if (!obj || typeof obj !== 'object') {
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throw new TypeError('argument obj is required')
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}
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var parameters = obj.parameters
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var subtype = obj.subtype
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var suffix = obj.suffix
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var type = obj.type
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if (!type || !typeNameRegExp.test(type)) {
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throw new TypeError('invalid type')
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}
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if (!subtype || !subtypeNameRegExp.test(subtype)) {
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throw new TypeError('invalid subtype')
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}
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// format as type/subtype
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var string = type + '/' + subtype
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// append +suffix
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if (suffix) {
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if (!typeNameRegExp.test(suffix)) {
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throw new TypeError('invalid suffix')
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}
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string += '+' + suffix
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}
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// append parameters
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if (parameters && typeof parameters === 'object') {
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var param
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var params = Object.keys(parameters).sort()
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for (var i = 0; i < params.length; i++) {
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param = params[i]
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if (!tokenRegExp.test(param)) {
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throw new TypeError('invalid parameter name')
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}
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string += '; ' + param + '=' + qstring(parameters[param])
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}
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}
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return string
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}
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/**
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* Parse media type to object.
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*
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* @param {string|object} string
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* @return {Object}
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* @api public
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*/
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function parse(string) {
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if (!string) {
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throw new TypeError('argument string is required')
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}
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// support req/res-like objects as argument
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if (typeof string === 'object') {
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string = getcontenttype(string)
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}
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if (typeof string !== 'string') {
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throw new TypeError('argument string is required to be a string')
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}
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var index = string.indexOf(';')
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var type = index !== -1
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? string.substr(0, index)
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: string
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var key
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var match
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var obj = splitType(type)
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var params = {}
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var value
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paramRegExp.lastIndex = index
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while (match = paramRegExp.exec(string)) {
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if (match.index !== index) {
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throw new TypeError('invalid parameter format')
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}
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index += match[0].length
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key = match[1].toLowerCase()
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value = match[2]
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if (value[0] === '"') {
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// remove quotes and escapes
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value = value
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.substr(1, value.length - 2)
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.replace(qescRegExp, '$1')
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}
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params[key] = value
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}
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if (index !== -1 && index !== string.length) {
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throw new TypeError('invalid parameter format')
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}
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obj.parameters = params
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return obj
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}
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/**
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* Get content-type from req/res objects.
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*
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* @param {object}
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* @return {Object}
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* @api private
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*/
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function getcontenttype(obj) {
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if (typeof obj.getHeader === 'function') {
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// res-like
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return obj.getHeader('content-type')
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}
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if (typeof obj.headers === 'object') {
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// req-like
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return obj.headers && obj.headers['content-type']
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}
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}
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/**
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* Quote a string if necessary.
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*
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* @param {string} val
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* @return {string}
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* @api private
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*/
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function qstring(val) {
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var str = String(val)
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// no need to quote tokens
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if (tokenRegExp.test(str)) {
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return str
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}
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if (str.length > 0 && !textRegExp.test(str)) {
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throw new TypeError('invalid parameter value')
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}
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return '"' + str.replace(quoteRegExp, '\\$1') + '"'
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}
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/**
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* Simply "type/subtype+siffx" into parts.
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*
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* @param {string} string
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* @return {Object}
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* @api private
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*/
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function splitType(string) {
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var match = typeRegExp.exec(string.toLowerCase())
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if (!match) {
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throw new TypeError('invalid media type')
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}
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var type = match[1]
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var subtype = match[2]
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var suffix
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// suffix after last +
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var index = subtype.lastIndexOf('+')
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if (index !== -1) {
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suffix = subtype.substr(index + 1)
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subtype = subtype.substr(0, index)
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}
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var obj = {
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type: type,
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subtype: subtype,
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suffix: suffix
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}
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return obj
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}
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