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use a simple expression parser instead of regexp to parse directive #3734

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Merged
merged 1 commit into from
Sep 23, 2016
Merged

use a simple expression parser instead of regexp to parse directive #3734

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226 changes: 167 additions & 59 deletions src/parsers/directive.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2,36 +2,173 @@ import { toNumber, stripQuotes } from '../util/index'
import Cache from '../cache'

const cache = new Cache(1000)
const filterTokenRE = /[^\s'"]+|'[^']*'|"[^"]*"/g
const reservedArgRE = /^in$|^-?\d+/

/**
* Parser state
*/

var str, dir
var c, prev, i, l, lastFilterIndex
var inSingle, inDouble, curly, square, paren
var str, dir, len
var index
var chr
var state
var startState = 0
var filterState = 1
var filterNameState = 2
var filterArgState = 3

var doubleChr = 0x22
var singleChr = 0x27
var pipeChr = 0x7C
var escapeChr = 0x5C
var spaceChr = 0x20

var expStartChr = { 0x5B: 1, 0x7B: 1, 0x28: 1 }
var expChrPair = { 0x5B: 0x5D, 0x7B: 0x7D, 0x28: 0x29 }

function peek () {
return str.charCodeAt(index + 1)
}

function next () {
return str.charCodeAt(++index)
}

function eof () {
return index >= len
}

function eatSpace () {
while (peek() === spaceChr) {
next()
}
}

function isStringStart (chr) {
return chr === doubleChr || chr === singleChr
}

function isExpStart (chr) {
return expStartChr[chr]
}

function isExpEnd (start, chr) {
return expChrPair[start] === chr
}

function parseString () {
var stringQuote = next()
var chr
while (!eof()) {
chr = next()
// escape char
if (chr === escapeChr) {
next()
} else if (chr === stringQuote) {
break
}
}
}

function parseSpecialExp (chr) {
var inExp = 0
var startChr = chr

while (!eof()) {
chr = peek()
if (isStringStart(chr)) {
parseString()
continue
}

if (startChr === chr) {
inExp++
}
if (isExpEnd(startChr, chr)) {
inExp--
}

next()

if (inExp === 0) {
break
}
}
}

/**
* Push a filter to the current directive object
* syntax:
* expression | filterName [arg arg [| filterName arg arg]]
*/

function pushFilter () {
var exp = str.slice(lastFilterIndex, i).trim()
var filter
if (exp) {
filter = {}
var tokens = exp.match(filterTokenRE)
filter.name = tokens[0]
if (tokens.length > 1) {
filter.args = tokens.slice(1).map(processFilterArg)
function parseExpression () {
var start = index
while (!eof()) {
chr = peek()
if (isStringStart(chr)) {
parseString()
} else if (isExpStart(chr)) {
parseSpecialExp(chr)
} else if (chr === pipeChr) {
next()
chr = peek()
if (chr === pipeChr) {
next()
} else {
if (state === startState || state === filterArgState) {
state = filterState
}
break
}
} else if (chr === spaceChr && (state === filterNameState || state === filterArgState)) {
eatSpace()
break
} else {
if (state === filterState) {
state = filterNameState
}
next()
}
}
if (filter) {
(dir.filters = dir.filters || []).push(filter)

return str.slice(start + 1, index) || null
}

function parseFilterList () {
var filters = []
while (!eof()) {
filters.push(parseFilter())
}
lastFilterIndex = i + 1
return filters
}

function parseFilter () {
var filter = {}
var args

state = filterState
filter.name = parseExpression().trim()

state = filterArgState
args = parseFilterArguments()

if (args.length) {
filter.args = args
}
return filter
}

function parseFilterArguments () {
var args = []
while (!eof() && state !== filterState) {
var arg = parseExpression()
if (!arg) {
break
}
args.push(processFilterArg(arg))
}

return args
}

/**
Expand Down Expand Up @@ -83,51 +220,22 @@ export function parseDirective (s) {

// reset parser state
str = s
inSingle = inDouble = false
curly = square = paren = 0
lastFilterIndex = 0
dir = {}
len = str.length
index = -1
chr = ''
state = startState

for (i = 0, l = str.length; i < l; i++) {
prev = c
c = str.charCodeAt(i)
if (inSingle) {
// check single quote
if (c === 0x27 && prev !== 0x5C) inSingle = !inSingle
} else if (inDouble) {
// check double quote
if (c === 0x22 && prev !== 0x5C) inDouble = !inDouble
} else if (
c === 0x7C && // pipe
str.charCodeAt(i + 1) !== 0x7C &&
str.charCodeAt(i - 1) !== 0x7C
) {
if (dir.expression == null) {
// first filter, end of expression
lastFilterIndex = i + 1
dir.expression = str.slice(0, i).trim()
} else {
// already has filter
pushFilter()
}
} else {
switch (c) {
case 0x22: inDouble = true; break // "
case 0x27: inSingle = true; break // '
case 0x28: paren++; break // (
case 0x29: paren--; break // )
case 0x5B: square++; break // [
case 0x5D: square--; break // ]
case 0x7B: curly++; break // {
case 0x7D: curly--; break // }
}
}
}
var filters

if (dir.expression == null) {
dir.expression = str.slice(0, i).trim()
} else if (lastFilterIndex !== 0) {
pushFilter()
if (str.indexOf('|') < 0) {
dir.expression = str.trim()
} else {
dir.expression = parseExpression().trim()
filters = parseFilterList()
if (filters.length) {
dir.filters = filters
}
}

cache.put(s, dir)
Expand Down
26 changes: 26 additions & 0 deletions test/unit/specs/parsers/directive_spec.js
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Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,32 @@ describe('Directive Parser', function () {
expect(res.filters[0].args).toBeUndefined()
})

it('white spaces inside object literal', function () {
var res = parse('abc | filter {a:1} {b: 2}')
expect(res.expression).toBe('abc')
expect(res.filters.length).toBe(1)
expect(res.filters[0].name).toBe('filter')
expect(res.filters[0].args.length).toBe(2)
expect(res.filters[0].args[0].value).toBe('{a:1}')
expect(res.filters[0].args[0].dynamic).toBe(true)
expect(res.filters[0].args[1].value).toBe('{b: 2}')
expect(res.filters[0].args[1].dynamic).toBe(true)
})

it('white spaces inside array literal', function () {
var res = parse('abc | filter0 abc||def | filter1 [ 1, { a: 2 }]')
expect(res.expression).toBe('abc')
expect(res.filters.length).toBe(2)
expect(res.filters[0].name).toBe('filter0')
expect(res.filters[0].args.length).toBe(1)
expect(res.filters[0].args[0].value).toBe('abc||def')
expect(res.filters[0].args[0].dynamic).toBe(true)
expect(res.filters[1].name).toBe('filter1')
expect(res.filters[1].args.length).toBe(1)
expect(res.filters[1].args[0].value).toBe('[ 1, { a: 2 }]')
expect(res.filters[1].args[0].dynamic).toBe(true)
})

it('cache', function () {
var res1 = parse('a || b | c')
var res2 = parse('a || b | c')
Expand Down