shrimp/src/parser/tokenizer2.ts
2025-11-12 21:46:29 -08:00

509 lines
11 KiB
TypeScript

const DEBUG = process.env.DEBUG || false
export type Token = {
type: TokenType
value?: string,
from: number,
to: number,
}
export enum TokenType {
Comment,
Keyword,
Operator,
Newline,
Semicolon,
Colon,
Underscore,
OpenParen,
CloseParen,
OpenBracket,
CloseBracket,
Identifier,
Word,
NamedArgPrefix,
Null,
Boolean,
Number,
String,
}
const valueTokens = new Set([
TokenType.Comment,
TokenType.Keyword, TokenType.Operator,
TokenType.Identifier, TokenType.Word, TokenType.NamedArgPrefix,
TokenType.Boolean, TokenType.Number, TokenType.String
])
const operators = new Set([
// assignment
'=',
// logic
'or',
'and',
// bitwise
'band',
'bor',
'bxor',
'>>>',
'>>',
'<<',
// compound assignment
'??=',
'+=',
'-=',
'*=',
'/=',
'%=',
// nullish
'??',
// math
'**',
'*',
'/',
'+',
'-',
'%',
// comparison
'>=',
'<=',
'!=',
'==',
'>',
'<',
])
const keywords = new Set([
'import',
'end',
'do',
'if',
'while',
'if',
'else',
'try',
'catch',
'finally',
'throw',
])
// helper
function c(strings: TemplateStringsArray, ...values: any[]) {
return strings.reduce((result, str, i) => result + str + (values[i] ?? ""), "").charCodeAt(0)
}
function s(c: number): string {
return String.fromCharCode(c)
}
export class Scanner {
input = ''
pos = 0
start = 0
char = 0
prev = 0
inParen = 0
inBracket = 0
tokens: Token[] = []
reset() {
this.input = ''
this.pos = 0
this.start = 0
this.char = 0
this.prev = 0
this.tokens.length = 0
}
peek(count = 0): number {
return getFullCodePoint(this.input, this.pos + count)
}
next(): number {
this.prev = this.char
this.char = this.peek()
this.pos += getCharSize(this.char)
return this.char
}
push(type: TokenType, from?: number, to?: number) {
from ??= this.start
to ??= this.pos - getCharSize(this.char)
if (to < from) to = from
this.tokens.push(Object.assign({}, {
type,
from,
to,
}, valueTokens.has(type) ? { value: this.input.slice(from, to) } : {}))
if (DEBUG) {
const tok = this.tokens.at(-1)
console.log(`≫ PUSH(${from},${to})`, TokenType[tok?.type || 0], '—', tok?.value)
}
this.start = this.pos
}
// turn shrimp code into shrimp tokens that get fed into the parser
tokenize(input: string): Token[] {
this.reset()
this.input = input
this.next()
while (this.char > 0) {
const char = this.char
if (char === c`#`) {
this.readComment()
continue
}
if (isBracket(char)) {
this.readBracket()
continue
}
if (isStringDelim(char)) {
this.readString(char)
continue
}
if (char === c`{`) {
this.readCurlyString()
continue
}
if (isIdentStart(char)) {
this.readIdentOrKeyword()
continue
}
if (isDigit(char) || ((char === c`-` || char === c`+`) && isDigit(this.peek()))) {
this.readNumber()
continue
}
if (char === c`:`) {
this.push(TokenType.Colon, this.start - 1, this.pos) // TODO: why?
this.next()
continue
}
if (isWordChar(char)) {
this.readWord()
continue
}
if (char === c`\n`) {
if (this.inParen === 0 && this.inBracket === 0)
this.push(TokenType.Newline)
this.next()
continue
}
if (char === c`;`) {
this.push(TokenType.Semicolon)
this.next()
continue
}
this.next()
}
return this.tokens
}
readComment() {
while (this.char !== c`\n` && this.char > 0) this.next()
this.push(TokenType.Comment)
}
readBracket() {
switch (this.char) {
case c`(`:
this.inParen++
this.push(TokenType.OpenParen); break
case c`)`:
this.inParen--
this.push(TokenType.CloseParen); break
case c`[`:
this.inBracket++
this.push(TokenType.OpenBracket); break
case c`]`:
this.inBracket--
this.push(TokenType.CloseBracket); break
}
this.next()
}
readString(delim: number) {
this.start = this.pos - 1
this.next() // skip opening delim
while (this.char > 0 && (this.char !== delim || (this.char === delim && this.prev === c`\\`)))
this.next()
this.next() // skip closing delim
this.push(TokenType.String)
}
readCurlyString() {
let depth = 1
this.next()
while (depth > 0 && this.char > 0) {
if (this.char === c`{`) depth++
if (this.char === c`}`) depth--
this.next()
}
this.push(TokenType.String)
}
readIdentOrKeyword() {
this.start = this.pos - getCharSize(this.char)
while (isWordChar(this.char)) {
// stop at colon if followed by whitespace (e.g., 'do x: echo x end')
if (this.char === c`:`) {
const nextCh = this.peek()
if (isWhitespace(nextCh) || nextCh === 0) break
}
// stop at equal sign (named arg)
if (this.char === c`=`) {
this.next()
break
}
this.next()
}
const ident = this.input.slice(this.start, this.pos - getCharSize(this.char))
if (ident === 'null')
this.push(TokenType.Null)
else if (ident === 'true' || ident === 'false')
this.push(TokenType.Boolean)
else if (isKeyword(ident))
this.push(TokenType.Keyword)
else if (isOperator(ident))
this.push(TokenType.Operator) // only things like `and` and `or`
else if (isIdentifer(ident))
this.push(TokenType.Identifier)
else if (ident.endsWith('='))
this.push(TokenType.NamedArgPrefix)
else
this.push(TokenType.Word)
}
readNumber() {
this.start = this.pos - 1
while (isWordChar(this.char)) {
// stop at colon
if (this.char === c`:`) {
const nextCh = this.peek()
if (isWhitespace(nextCh) || nextCh === 0) break
}
this.next()
}
const ident = this.input.slice(this.start, this.pos - 1)
this.push(isNumber(ident) ? TokenType.Number : TokenType.Word)
}
readWord() {
this.start = this.pos - getCharSize(this.char)
while (isWordChar(this.char)) this.next()
const word = this.input.slice(this.start, this.pos - getCharSize(this.char))
if (word === '_')
this.push(TokenType.Underscore)
else if (operators.has(word))
this.push(TokenType.Operator)
else
this.push(TokenType.Word)
}
}
const isNumber = (word: string): boolean => {
// regular number
if (/^[+-]?\d+(_?\d+)*(\.(\d+(_?\d+)*))?$/.test(word))
return true
// binary
if (/^[+-]?0b[01]+(_?[01]+)*(\.[01](_?[01]*))?$/.test(word))
return true
// octal
if (/^[+-]?0o[0-7]+(_?[0-7]+)*(\.[0-7](_?[0-7]*))?$/.test(word))
return true
// hex
if (/^[+-]?0x[0-9a-f]+([0-9a-f]_?[0-9a-f]+)*(\.([0-9a-f]_?[0-9a-f]*))?$/i.test(word))
return true
return false
}
const isIdentifer = (s: string): boolean => {
if (s.length === 0) return false
let pos = 0
const chars = []
while (pos < s.length) {
const out = getFullCodePoint(s, pos)
pos += getCharSize(out)
chars.push(out)
}
if (chars.length === 1)
return isIdentStart(chars[0]!)
else if (chars.length === 2)
return isIdentStart(chars[0]!) && isIdentEnd(chars[1]!)
else
return isIdentStart(chars[0]!) &&
chars.slice(1, chars.length - 1).every(isIdentChar) &&
isIdentEnd(chars.at(-1)!)
}
const isStringDelim = (ch: number): boolean => {
return ch === c`'` || ch === c`"`
}
const isIdentStart = (char: number | string): boolean => {
let ch = typeof char === 'string' ? char.charCodeAt(0) : char
return isLowercaseLetter(ch) || isEmojiOrUnicode(ch) || ch === 36 /* $ */
}
const isIdentChar = (char: number | string): boolean => {
let ch = typeof char === 'string' ? char.charCodeAt(0) : char
return isIdentStart(ch) || isDigit(ch) || ch === 45 /* - */ || ch === 63 /* ? */
}
const isIdentEnd = (char: number | string): boolean => {
return isIdentChar(char)
}
const isLowercaseLetter = (ch: number): boolean => {
return ch >= 97 && ch <= 122 // a-z
}
const isDigit = (ch: number): boolean => {
return ch >= 48 && ch <= 57 // 0-9
}
const isWhitespace = (ch: number): boolean => {
return ch === 32 /* space */ || ch === 9 /* tab */ ||
ch === 13 /* \r */ || ch === 10 /* \n */ ||
ch === -1 || ch === 0 /* EOF */
}
const isWordChar = (ch: number): boolean => {
return (
!isWhitespace(ch) &&
ch !== 10 /* \n */ &&
ch !== 59 /* ; */ &&
ch !== 41 /* ) */ &&
ch !== 93 /* ] */ &&
ch !== -1 /* EOF */
)
}
const isOperator = (word: string): boolean => {
return operators.has(word)
}
const isKeyword = (word: string): boolean => {
return keywords.has(word)
}
const isBracket = (char: number): boolean => {
return char === c`(` || char === c`)` || char === c`[` || char === c`]`
}
const getCharSize = (ch: number) =>
(ch > 0xffff ? 2 : 1) // emoji takes 2 UTF-16 code units
const getFullCodePoint = (input: string, pos: number): number => {
const ch = input[pos]?.charCodeAt(0) || 0
// Check if this is a high surrogate (0xD800-0xDBFF)
if (ch >= 0xd800 && ch <= 0xdbff) {
const low = input[pos + 1]?.charCodeAt(0) || 0
// Check if next is low surrogate (0xDC00-0xDFFF)
if (low >= 0xdc00 && low <= 0xdfff) {
// Combine surrogate pair into full code point
return 0x10000 + ((ch & 0x3ff) << 10) + (low & 0x3ff)
}
}
return ch
}
const isEmojiOrUnicode = (ch: number): boolean => {
return (
// Basic Emoticons
(ch >= 0x1f600 && ch <= 0x1f64f) ||
// Miscellaneous Symbols and Pictographs
(ch >= 0x1f300 && ch <= 0x1f5ff) ||
// Transport and Map Symbols
(ch >= 0x1f680 && ch <= 0x1f6ff) ||
// Regional Indicator Symbols (flags)
(ch >= 0x1f1e6 && ch <= 0x1f1ff) ||
// Miscellaneous Symbols (hearts, stars, weather)
(ch >= 0x2600 && ch <= 0x26ff) ||
// Dingbats (scissors, pencils, etc)
(ch >= 0x2700 && ch <= 0x27bf) ||
// Supplemental Symbols and Pictographs (newer emojis)
(ch >= 0x1f900 && ch <= 0x1f9ff) ||
// Symbols and Pictographs Extended-A (newest emojis)
(ch >= 0x1fa70 && ch <= 0x1faff) ||
// Various Asian Characters with emoji presentation
(ch >= 0x1f018 && ch <= 0x1f270) ||
// Variation Selectors (for emoji presentation)
(ch >= 0xfe00 && ch <= 0xfe0f) ||
// Additional miscellaneous items
(ch >= 0x238c && ch <= 0x2454) ||
// Combining Diacritical Marks for Symbols
(ch >= 0x20d0 && ch <= 0x20ff) ||
// Latin-1 Supplement (includes ², ³, ¹ and other special chars)
(ch >= 0x00a0 && ch <= 0x00ff) ||
// Greek and Coptic (U+0370-U+03FF)
(ch >= 0x0370 && ch <= 0x03ff) ||
// Mathematical Alphanumeric Symbols (U+1D400-U+1D7FF)
(ch >= 0x1d400 && ch <= 0x1d7ff) ||
// Mathematical Operators (U+2200-U+22FF)
(ch >= 0x2200 && ch <= 0x22ff) ||
// Superscripts and Subscripts (U+2070-U+209F)
(ch >= 0x2070 && ch <= 0x209f) ||
// Arrows (U+2190-U+21FF)
(ch >= 0x2190 && ch <= 0x21ff) ||
// Hiragana (U+3040-U+309F)
(ch >= 0x3040 && ch <= 0x309f) ||
// Katakana (U+30A0-U+30FF)
(ch >= 0x30a0 && ch <= 0x30ff) ||
// CJK Unified Ideographs (U+4E00-U+9FFF)
(ch >= 0x4e00 && ch <= 0x9fff)
)
}