use std::cmp::Ordering;
use erg_common::cache::CacheSet;
use erg_common::config::ErgConfig;
use erg_common::config::Input;
use erg_common::traits::{Locational, Runnable, Stream};
use erg_common::{debug_power_assert, fn_name_full, normalize_newline, switch_lang};
use crate::error::{LexError, LexErrors, LexResult, LexerRunnerError, LexerRunnerErrors};
use crate::token::{Token, TokenCategory, TokenKind, TokenStream};
use TokenKind::*;
pub struct LexerRunner {
cfg: ErgConfig,
}
impl Runnable for LexerRunner {
type Err = LexerRunnerError;
type Errs = LexerRunnerErrors;
const NAME: &'static str = "Erg lexer";
#[inline]
fn new(cfg: ErgConfig) -> Self {
Self { cfg }
}
#[inline]
fn cfg(&self) -> &ErgConfig {
&self.cfg
}
#[inline]
fn finish(&mut self) {}
#[inline]
fn clear(&mut self) {}
fn exec(&mut self) -> Result<(), Self::Errs> {
let lexer = Lexer::from_str(self.input().read());
let ts = lexer
.lex()
.map_err(|errs| LexerRunnerErrors::convert(self.input(), errs))?;
println!("{ts}");
Ok(())
}
fn eval(&mut self, src: String) -> Result<String, LexerRunnerErrors> {
let lexer = Lexer::from_str(src);
if cfg!(feature = "debug") {
let ts = lexer
.lex()
.map_err(|errs| LexerRunnerErrors::convert(self.input(), errs))?;
println!("{ts}");
Ok(ts.to_string())
} else {
Ok(lexer
.lex()
.map_err(|errs| LexerRunnerErrors::convert(self.input(), errs))?
.to_string())
}
}
}
#[derive(Debug)]
pub struct Lexer {
str_cache: CacheSet<str>,
chars: Vec<char>,
indent_stack: Vec<usize>,
cursor: usize,
prev_token: Token,
lineno_token_starts: usize,
col_token_starts: usize,
}
impl Lexer {
pub fn new(input: Input) -> Self {
let normed = normalize_newline(&input.read());
Lexer {
str_cache: CacheSet::new(),
chars: normed.chars().collect::<Vec<char>>(),
indent_stack: vec![],
cursor: 0,
prev_token: Token::new(TokenKind::BOF, "", 0, 0),
lineno_token_starts: 0,
col_token_starts: 0,
}
}
#[allow(clippy::should_implement_trait)]
pub fn from_str(src: String) -> Self {
let escaped = normalize_newline(&src);
Lexer {
str_cache: CacheSet::new(),
chars: escaped.chars().collect::<Vec<char>>(),
indent_stack: vec![],
cursor: 0,
prev_token: Token::new(TokenKind::BOF, "", 0, 0),
lineno_token_starts: 0,
col_token_starts: 0,
}
}
pub fn lex(self) -> Result<TokenStream, LexErrors> {
let mut result = TokenStream::empty();
let mut errs = LexErrors::empty();
for i in self {
match i {
Ok(token) => result.push(token),
Err(err) => {
errs.push(err);
}
}
}
if errs.is_empty() {
Ok(result)
} else {
Err(errs)
}
}
fn emit_token(&mut self, kind: TokenKind, cont: &str) -> Token {
let cont = self.str_cache.get(cont);
let cont_len = cont.chars().count();
let token = Token::new(
kind,
cont,
self.lineno_token_starts + 1,
self.col_token_starts,
);
self.prev_token = token.clone();
self.col_token_starts += cont_len;
token
}
#[inline]
fn accept(&mut self, kind: TokenKind, cont: &str) -> Option<LexResult<Token>> {
Some(Ok(self.emit_token(kind, cont)))
}
fn deny_feature(&mut self, cont: &str, feat_name: &str) -> Option<LexResult<Token>> {
let token = self.emit_token(Illegal, cont);
Some(Err(LexError::feature_error(0, token.loc(), feat_name)))
}
const fn is_valid_symbol_ch(c: char) -> bool {
match c {
'0'..='9' => true,
'\0' | '\u{0009}'..='\u{001F}' => false,
' ' | '\u{00A0}' => false,
'\u{007F}' | '\u{0085}' | '\u{05C1}' | '\u{05C2}' => false,
'\u{0701}'..='\u{070d}' => false,
'\u{07B2}'..='\u{07BF}' => false,
'\u{1680}' | '\u{180E}' => false,
'\u{2000}'..='\u{200F}' => false,
'\u{2028}'..='\u{202F}' => false,
'\u{205F}'..='\u{206F}' => false,
'\u{3000}' | '\u{3164}' | '\u{FEFF}' => false,
'<' | '>' | '$' | '%' | '.' | ',' | ':' | ';' | '+' | '-' | '*' | '/' | '=' | '#'
| '&' | '|' | '^' | '~' | '@' | '!' | '?' | '\\' => false,
'[' | ']' | '(' | ')' | '{' | '}' | '\"' | '\'' | '`' => false,
_ => true,
}
}
pub fn is_bidi(c: char) -> bool {
matches!(c, '\u{200F}' | '\u{202B}' | '\u{202E}' | '\u{2067}')
}
#[inline]
fn is_definable_operator(s: &str) -> bool {
matches!(
s,
"+" | "-"
| "*"
| "/"
| "//"
| "**"
| "%"
| ".."
| "..="
| "~"
| "&&"
| "||"
| "^^"
| ">>"
| "<<"
| "=="
| "!="
| ">"
| "<"
| ">="
| "<="
| "dot"
| "cross"
)
}
const fn is_bin_position(&self) -> Option<bool> {
match self.prev_token.category() {
TokenCategory::LEnclosure
| TokenCategory::BinOp
| TokenCategory::UnaryOp
| TokenCategory::Separator
| TokenCategory::SpecialBinOp
| TokenCategory::DefOp
| TokenCategory::LambdaOp
| TokenCategory::BOF => Some(false),
TokenCategory::REnclosure | TokenCategory::Literal => Some(true),
TokenCategory::Symbol => Some(true),
_ => None,
}
}
fn is_zero(s: &str) -> bool {
s.replace("-0", "").replace('0', "").is_empty()
}
fn consume(&mut self) -> Option<char> {
let now = self.cursor;
self.cursor += 1;
self.chars.get(now).copied()
}
fn peek_prev_ch(&self) -> Option<char> {
if self.cursor == 0 {
None
} else {
self.chars.get(self.cursor - 1).copied()
}
}
#[inline]
fn peek_cur_ch(&self) -> Option<char> {
self.chars.get(self.cursor).copied()
}
#[inline]
fn peek_next_ch(&self) -> Option<char> {
self.chars.get(self.cursor + 1).copied()
}
fn lex_comment(&mut self) -> LexResult<()> {
let mut s = "".to_string();
while self.peek_cur_ch().map(|cur| cur != '\n').unwrap_or(false) {
if Self::is_bidi(self.peek_cur_ch().unwrap()) {
let comment = self.emit_token(Illegal, &s);
return Err(LexError::syntax_error(
0,
comment.loc(),
switch_lang!(
"japanese" => "不正なユニコード文字(双方向オーバーライド)がコメント中に使用されています",
"simplified_chinese" => "注释中使用了非法的unicode字符(双向覆盖)",
"traditional_chinese" => "註釋中使用了非法的unicode字符(雙向覆蓋)",
"english" => "invalid unicode character (bi-directional override) in comments",
),
None,
));
}
s.push(self.consume().unwrap());
}
Ok(())
}
fn lex_space_indent_dedent(&mut self) -> Option<LexResult<Token>> {
let is_toplevel = self.cursor > 0
&& !self.indent_stack.is_empty()
&& self.peek_prev_ch() == Some('\n')
&& self.peek_cur_ch() != Some(' ');
if is_toplevel {
let dedent = self.emit_token(Dedent, "");
self.indent_stack.pop();
self.col_token_starts = 0;
return Some(Ok(dedent));
}
let mut spaces = "".to_string();
while let Some(' ') = self.peek_cur_ch() {
spaces.push(self.consume().unwrap());
}
if !spaces.is_empty() && self.cursor == 0 {
let space = self.emit_token(Illegal, &spaces);
Some(Err(LexError::syntax_error(
0,
space.loc(),
switch_lang!(
"japanese" => "インデントが不正です",
"simplified_chinese" => "无效缩进",
"traditional_chinese" => "無效縮進",
"english" => "invalid indent",
),
None,
)))
} else if self.prev_token.is(Newline) {
self.lex_indent_dedent(spaces)
} else {
self.col_token_starts += spaces.len();
None
}
}
fn lex_indent_dedent(&mut self, spaces: String) -> Option<LexResult<Token>> {
if spaces.len() > 100 {
let token = self.emit_token(Indent, &spaces);
return Some(Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => "インデントが深すぎます",
"simplified_chinese" => "缩进太深",
"traditional_chinese" => "縮進太深",
"english" => "indentation is too deep",
),
Some(
switch_lang!(
"japanese" => "コードが複雑すぎます。処理を分割してください",
"simplified_chinese" => "代码过于复杂,请拆分过程",
"traditional_chinese" => "代碼過於復雜,請拆分過程",
"english" => "The code is too complicated. Please split the process",
)
.into(),
),
)));
}
if let Some('#') = self.peek_cur_ch() {
if let Err(e) = self.lex_comment() {
return Some(Err(e));
}
}
let mut is_valid_dedent = false;
let calc_indent_and_validate = |sum: usize, x: &usize| {
if sum + *x == spaces.len() {
is_valid_dedent = true;
}
sum + *x
};
let sum_indent = self.indent_stack.iter().fold(0, calc_indent_and_validate);
match sum_indent.cmp(&spaces.len()) {
Ordering::Less => {
let indent_len = spaces.len() - sum_indent;
self.col_token_starts += sum_indent;
let indent = self.emit_token(Indent, &" ".repeat(indent_len));
self.indent_stack.push(indent_len);
Some(Ok(indent))
}
Ordering::Greater => {
if is_valid_dedent {
let dedent = self.emit_token(Dedent, "");
self.indent_stack.pop();
Some(Ok(dedent))
} else {
let invalid_dedent = self.emit_token(Dedent, "");
Some(Err(LexError::syntax_error(
0,
invalid_dedent.loc(),
switch_lang!(
"japanese" => "インデントが不正です",
"simplified_chinese" => "无效缩进",
"traditional_chinese" => "無效縮進",
"english" => "invalid indent",
),
None,
)))
}
}
Ordering::Equal => {
self.col_token_starts += spaces.len();
None
}
}
}
fn lex_exponent(&mut self, mantissa: String) -> LexResult<Token> {
let mut num = mantissa;
debug_power_assert!(self.peek_cur_ch(), ==, Some('e'));
num.push(self.consume().unwrap()); num.push(self.consume().unwrap()); while let Some(cur) = self.peek_cur_ch() {
if cur.is_ascii_digit() || cur == '_' {
num.push(self.consume().unwrap());
} else {
break;
}
}
Ok(self.emit_token(RatioLit, &num))
}
fn lex_num(&mut self, first_ch: char) -> LexResult<Token> {
let mut num = first_ch.to_string();
while let Some(ch) = self.peek_cur_ch() {
match ch {
'.' => {
return self.lex_num_dot(num);
}
n if n.is_ascii_digit() || n == '_' => {
num.push(self.consume().unwrap());
}
c if Self::is_valid_symbol_ch(c) => {
if c == 'e'
&& (self.peek_next_ch() == Some('+') || self.peek_next_ch() == Some('-'))
{
return self.lex_exponent(num);
} else {
let token = self.emit_token(Illegal, &(num + &c.to_string()));
return Err(LexError::feature_error(
line!() as usize,
token.loc(),
"*-less multiply",
));
}
}
_ => {
break;
}
}
}
let kind = if num.starts_with('-') && !Self::is_zero(&num) {
IntLit
} else {
NatLit
};
Ok(self.emit_token(kind, &num))
}
fn lex_num_dot(&mut self, mut num: String) -> LexResult<Token> {
match self.peek_next_ch() {
Some(n) if n.is_ascii_digit() => {
num.push(self.consume().unwrap());
self.lex_ratio(num)
}
Some(c) if Self::is_valid_symbol_ch(c) || c == '.' => {
let kind = if num.starts_with('-') && !Self::is_zero(&num) {
IntLit
} else {
NatLit
};
Ok(self.emit_token(kind, &num))
}
Some('_') => {
self.consume();
let token = self.emit_token(Illegal, &(num + "_"));
Err(LexError::simple_syntax_error(0, token.loc()))
}
_ => {
num.push(self.consume().unwrap());
self.lex_ratio(num)
}
}
}
fn lex_ratio(&mut self, intpart_and_point: String) -> LexResult<Token> {
let mut num = intpart_and_point;
while let Some(cur) = self.peek_cur_ch() {
if cur.is_ascii_digit() || cur == '_' {
num.push(self.consume().unwrap());
} else if cur == 'e' {
return self.lex_exponent(num);
} else {
break;
}
}
Ok(self.emit_token(RatioLit, &num))
}
fn lex_symbol(&mut self, first_ch: char) -> LexResult<Token> {
let mut cont = first_ch.to_string();
while let Some(c) = self.peek_cur_ch() {
if Self::is_valid_symbol_ch(c) {
cont.push(self.consume().unwrap());
} else {
break;
}
}
if let Some('!') = self.peek_cur_ch() {
cont.push(self.consume().unwrap());
}
if cont.is_empty() {
let token = self.emit_token(Illegal, &self.peek_cur_ch().unwrap().to_string());
return Err(LexError::compiler_bug(
0,
token.loc(),
fn_name_full!(),
line!(),
));
}
let kind = match &cont[..] {
"and" => AndOp,
"or" => OrOp,
"in" => InOp,
"notin" => NotInOp,
"is" => IsOp,
"isnot" => IsNotOp,
"dot" => DotOp,
"cross" => CrossOp,
"ref" => RefOp,
"ref!" => RefMutOp,
"True" | "False" => BoolLit,
"None" => NoneLit,
"NotImplemented" => NoImplLit,
"Ellipsis" => EllipsisLit,
"Inf" => InfLit,
"_" => UBar,
_ => Symbol,
};
Ok(self.emit_token(kind, &cont))
}
fn lex_str(&mut self) -> LexResult<Token> {
let mut s = "\"".to_string();
while let Some(c) = self.peek_cur_ch() {
if c == '\"' {
s.push(self.consume().unwrap());
let token = self.emit_token(StrLit, &s);
return Ok(token);
} else {
let c = self.consume().unwrap();
if c == '\\' {
let next_c = self.consume().unwrap();
match next_c {
'0' => s.push('\0'),
'r' => s.push('\r'),
'n' => s.push('\n'),
'\'' => s.push('\''),
't' => s.push_str(" "), '\\' => s.push('\\'),
_ => {
let token = self.emit_token(Illegal, &format!("\\{next_c}"));
return Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => format!("不正なエスケープシーケンスです: \\{}", next_c),
"simplified_chinese" => format!("不合法的转义序列: \\{}", next_c),
"traditional_chinese" => format!("不合法的轉義序列: \\{}", next_c),
"english" => format!("illegal escape sequence: \\{}", next_c),
),
None,
));
}
}
} else {
s.push(c);
if Self::is_bidi(c) {
return Err(self._invalid_unicode_character(&s));
}
}
}
}
let token = self.emit_token(Illegal, &s);
Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => "文字列が\"によって閉じられていません",
"simplified_chinese" => "字符串没有被\"关闭",
"traditional_chinese" => "字符串没有被\"关闭",
"english" => "the string is not closed by \"",
),
None,
))
}
fn _invalid_unicode_character(&mut self, s: &str) -> LexError {
let token = self.emit_token(Illegal, s);
LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => "不正なユニコード文字(双方向オーバーライド)が文字列中に使用されています",
"simplified_chinese" => "注释中使用了非法的unicode字符(双向覆盖)",
"traditional_chinese" => "註釋中使用了非法的unicode字符(雙向覆蓋)",
"english" => "invalid unicode character (bi-directional override) in string literal",
),
None,
)
}
}
impl Iterator for Lexer {
type Item = LexResult<Token>;
fn next(&mut self) -> Option<Self::Item> {
if self.prev_token.is(TokenKind::EOF) {
return None;
}
let indent_dedent = self.lex_space_indent_dedent();
if indent_dedent.is_some() {
return indent_dedent;
}
if let Some('#') = self.peek_cur_ch() {
if let Err(e) = self.lex_comment() {
return Some(Err(e));
}
}
match self.consume() {
Some('(') => self.accept(LParen, "("),
Some(')') => self.accept(RParen, ")"),
Some('[') => self.accept(LSqBr, "["),
Some(']') => self.accept(RSqBr, "]"),
Some('{') => self.accept(LBrace, "{"),
Some('}') => self.accept(RBrace, "}"),
Some('<') => match self.peek_cur_ch() {
Some('.') => {
self.consume();
if let Some('.') = self.peek_cur_ch() {
self.consume();
match self.peek_cur_ch() {
Some('<') => {
self.consume();
self.accept(Open, "<..<")
}
_ => self.accept(LeftOpen, "<.."),
}
} else {
let token = self.emit_token(Illegal, "<.");
Some(Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => "<.という演算子はありません",
"simplified_chinese" => "没有这样的运算符:<.",
"traditional_chinese" => "沒有這樣的運算符:<.",
"english" => "no such operator: <.",
),
None,
)))
}
}
Some('=') => {
self.consume();
self.accept(LessEq, "<=")
}
Some('<') => {
self.consume();
self.accept(Shl, "<<")
}
Some(':') => {
self.consume();
self.accept(SubtypeOf, "<:")
}
_ => self.accept(Less, "<"),
},
Some('>') => match self.peek_cur_ch() {
Some('=') => {
self.consume();
self.accept(GreEq, ">=")
}
Some('>') => {
self.consume();
self.accept(Shr, ">>")
}
_ => self.accept(Gre, ">"),
},
Some('.') => match self.peek_cur_ch() {
Some('.') => {
self.consume();
match self.peek_cur_ch() {
Some('<') => {
self.consume();
self.accept(RightOpen, "..<")
}
Some('.') => {
self.consume();
self.accept(EllipsisLit, "...")
}
_ => self.accept(Closed, ".."),
}
}
Some(c) if c.is_ascii_digit() && !self.prev_token.is(Symbol) => {
Some(self.lex_ratio(".".into()))
}
_ => self.accept(Dot, "."),
},
Some(',') => self.accept(Comma, ","),
Some(':') => match self.peek_cur_ch() {
Some(':') => {
self.consume();
self.accept(DblColon, "::")
}
Some('=') => {
self.consume();
self.accept(Walrus, ":=")
}
Some('>') => {
self.consume();
self.accept(SupertypeOf, ":>")
}
_ => self.accept(Colon, ":"),
},
Some(';') => self.accept(Semi, ";"),
Some('&') => {
if let Some('&') = self.peek_cur_ch() {
self.consume();
self.accept(BitAnd, "&&")
} else {
self.accept(Amper, "&")
}
}
Some('|') => match self.peek_cur_ch() {
Some('|') => {
self.consume();
self.accept(BitOr, "||")
}
_ => self.accept(VBar, "|"),
},
Some('^') => {
if let Some('^') = self.peek_cur_ch() {
self.consume();
self.accept(BitXor, "^^")
} else {
self.accept(Caret, "^")
}
}
Some('~') => self.accept(PreBitNot, "~"),
Some('$') => self.deny_feature("$", "shared variables"),
Some('@') => self.accept(AtSign, "@"),
Some('=') => match self.peek_cur_ch() {
Some('=') => {
self.consume();
self.accept(DblEq, "==")
}
Some('>') => {
self.consume();
self.accept(ProcArrow, "=>")
}
_ => self.accept(Equal, "="),
},
Some('!') => {
if let Some('=') = self.peek_cur_ch() {
self.consume();
self.accept(NotEq, "!=")
} else {
self.accept(Mutate, "!")
}
}
Some('?') => self.accept(Try, "?"),
Some('+') => {
let kind = match self.is_bin_position() {
Some(true) => Plus,
Some(false) => PrePlus,
None => {
let token = self.emit_token(Illegal, "+");
return Some(Err(LexError::simple_syntax_error(0, token.loc())));
}
};
self.accept(kind, "+")
}
Some('-') => match self.peek_cur_ch() {
Some('>') => {
self.consume();
self.accept(FuncArrow, "->")
}
_ => {
match self.is_bin_position() {
Some(true) => self.accept(Minus, "-"),
Some(false) => {
if self
.peek_cur_ch()
.map(|t| t.is_ascii_digit())
.unwrap_or(false)
{
Some(self.lex_num('-'))
} else {
self.accept(PreMinus, "-")
}
}
None => {
let token = self.emit_token(Illegal, "-");
Some(Err(LexError::simple_syntax_error(0, token.loc())))
}
}
}
},
Some('*') => match self.peek_cur_ch() {
Some('*') => {
self.consume();
self.accept(Pow, "**")
}
_ => {
let kind = match self.is_bin_position() {
Some(true) => Star,
_ => {
let token = self.emit_token(Illegal, "*");
return Some(Err(LexError::simple_syntax_error(0, token.loc())));
}
};
self.accept(kind, "*")
}
},
Some('/') => match self.peek_cur_ch() {
Some('/') => {
self.consume();
self.accept(FloorDiv, "//")
}
_ => self.accept(Slash, "/"),
},
Some('%') => self.accept(Mod, "%"),
Some('\n') => {
let token = self.emit_token(Newline, "\n");
self.lineno_token_starts += 1;
self.col_token_starts = 0;
Some(Ok(token))
}
Some('\t') => {
let token = self.emit_token(Illegal, "\t");
Some(Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => "タブ文字は使用できません",
"simplified_chinese" => "不能将制表符用作空格",
"traditional_chinese" => "不能將製表符用作空格",
"english" => "cannot use a tab as a space",
),
Some(
switch_lang!(
"japanese" => "スペース( )を使用してください",
"simplified_chinese" => "使用空格( )",
"traditional_chinese" => "使用空格( )",
"english" => "use spaces ( )",
)
.into(),
),
)))
}
Some('\\') => self.deny_feature("\\", "ignoring line break"),
Some('\"') => Some(self.lex_str()),
Some('\'') => self.deny_feature("'", "raw identifier"),
Some('`') => {
let mut op = "".to_string();
while let Some(c) = self.consume() {
if c == '`' {
if Self::is_definable_operator(&op[..]) {
return self.accept(Symbol, &op);
} else {
let token = self.emit_token(Illegal, &op);
return Some(Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => format!("`{}`はユーザー定義できません", &token.content),
"simplified_chinese" => format!("`{}`不能由用户定义", &token.content),
"traditional_chinese" => format!("`{}`不能由用戶定義", &token.content),
"english" => format!("`{}` cannot be defined by user", &token.content),
),
None,
)));
}
}
op.push(c);
}
let token = self.emit_token(Illegal, &op);
Some(Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => format!("バッククォート(`)が閉じられていません"),
"simplified_chinese" => format!("反引号(`)未关闭"),
"traditional_chinese" => format!("反引號(`)未關閉"),
"english" => format!("back quotes (`) not closed"),
),
None,
)))
}
Some(n) if n.is_ascii_digit() => Some(self.lex_num(n)),
Some(c) if Self::is_valid_symbol_ch(c) => Some(self.lex_symbol(c)),
Some(invalid) => {
let token = self.emit_token(Illegal, &invalid.to_string());
Some(Err(LexError::syntax_error(
0,
token.loc(),
switch_lang!(
"japanese" => format!("この文字は使用できません: '{invalid}'"),
"simplified_chinese" => format!("无效字符:'{invalid}'"),
"traditional_chinese" => format!("無效字符:'{invalid}'"),
"english" => format!("invalid character: '{invalid}'"),
),
None,
)))
}
None => {
if self.indent_stack.is_empty() {
self.accept(EOF, "")
} else {
self.indent_stack.pop();
self.accept(Dedent, "")
}
}
}
}
}