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import {reservedWords, keywords} from "./identifier"
import {types as tt} from "./tokentype"
import {lineBreak} from "./whitespace"
import {getOptions} from "./options"
// Registered plugins
export const plugins = {}
function keywordRegexp(words) {
return new RegExp("^(" + words.replace(/ /g, "|") + ")$")
}
export class Parser {
constructor(options, input, startPos) {
this.options = options = getOptions(options)
this.sourceFile = options.sourceFile
this.keywords = keywordRegexp(keywords[options.ecmaVersion >= 6 ? 6 : 5])
let reserved = ""
if (!options.allowReserved) {
for (let v = options.ecmaVersion;; v--)
if (reserved = reservedWords[v]) break
if (options.sourceType == "module") reserved += " await"
}
this.reservedWords = keywordRegexp(reserved)
let reservedStrict = (reserved ? reserved + " " : "") + reservedWords.strict
this.reservedWordsStrict = keywordRegexp(reservedStrict)
this.reservedWordsStrictBind = keywordRegexp(reservedStrict + " " + reservedWords.strictBind)
this.input = String(input)
// Used to signal to callers of `readWord1` whether the word
// contained any escape sequences. This is needed because words with
// escape sequences must not be interpreted as keywords.
this.containsEsc = false
// Load plugins
this.loadPlugins(options.plugins)
// Set up token state
// The current position of the tokenizer in the input.
if (startPos) {
this.pos = startPos
this.lineStart = this.input.lastIndexOf("\n", startPos - 1) + 1
this.curLine = this.input.slice(0, this.lineStart).split(lineBreak).length
} else {
this.pos = this.lineStart = 0
this.curLine = 1
}
// Properties of the current token:
// Its type
this.type = tt.eof
// For tokens that include more information than their type, the value
this.value = null
// Its start and end offset
this.start = this.end = this.pos
// And, if locations are used, the {line, column} object
// corresponding to those offsets
this.startLoc = this.endLoc = this.curPosition()
// Position information for the previous token
this.lastTokEndLoc = this.lastTokStartLoc = null
this.lastTokStart = this.lastTokEnd = this.pos
// The context stack is used to superficially track syntactic
// context to predict whether a regular expression is allowed in a
// given position.
this.context = this.initialContext()
this.exprAllowed = true
// Figure out if it's a module code.
this.inModule = options.sourceType === "module"
this.strict = this.inModule || this.strictDirective(this.pos)
// Used to signify the start of a potential arrow function
this.potentialArrowAt = -1
// Flags to track whether we are in a function, a generator, an async function.
this.inFunction = this.inGenerator = this.inAsync = false
// Positions to delayed-check that yield/await does not exist in default parameters.
this.yieldPos = this.awaitPos = 0
// Labels in scope.
this.labels = []
// If enabled, skip leading hashbang line.
if (this.pos === 0 && options.allowHashBang && this.input.slice(0, 2) === "#!")
this.skipLineComment(2)
// Scope tracking for duplicate variable names (see scope.js)
this.scopeStack = []
this.enterFunctionScope()
}
// DEPRECATED Kept for backwards compatibility until 3.0 in case a plugin uses them
isKeyword(word) { return this.keywords.test(word) }
isReservedWord(word) { return this.reservedWords.test(word) }
extend(name, f) {
this[name] = f(this[name])
}
loadPlugins(pluginConfigs) {
for (let name in pluginConfigs) {
let plugin = plugins[name]
if (!plugin) throw new Error("Plugin '" + name + "' not found")
plugin(this, pluginConfigs[name])
}
}
parse() {
let node = this.options.program || this.startNode()
this.nextToken()
return this.parseTopLevel(node)
}
}
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