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//! Generated BQL tokenizer. Do not edit by hand.
//!
//! Driven by the token definitions in `spec/bql.rules`.
use crate::ast::BinOp;
use crate::error::{BqlError, BqlResult};
#[derive(Debug, Clone, PartialEq)]
pub struct Token<'a> {
pub kind: TokenKind<'a>,
pub offset: usize,
}
#[derive(Debug, Clone, PartialEq)]
pub enum TokenKind<'a> {
LParen,
RParen,
Comma,
Op(BinOp),
Str(&'a str),
Word(&'a str),
Eof,
}
pub fn lex<'a>(input: &'a str) -> BqlResult<Vec<Token<'a>>> {
let mut out = Vec::new();
let mut i = 0usize;
let n = input.len();
while i < n {
let c = input[i..].chars().next().expect("in-bounds");
if is_whitespace_char(c) {
i += c.len_utf8();
continue;
}
let start = i;
match c {
',' => {
out.push(Token {
kind: TokenKind::Comma,
offset: start,
});
i += 1;
}
'(' => {
out.push(Token {
kind: TokenKind::LParen,
offset: start,
});
i += 1;
}
'!' => {
if input[i..].starts_with("!^=") {
out.push(Token {
kind: TokenKind::Op(BinOp::NotStartsWith),
offset: start,
});
i += 3;
continue;
}
if input[i..].starts_with("!$=") {
out.push(Token {
kind: TokenKind::Op(BinOp::NotEndsWith),
offset: start,
});
i += 3;
continue;
}
if input[i..].starts_with("!=") {
out.push(Token {
kind: TokenKind::Op(BinOp::Neq),
offset: start,
});
i += 2;
continue;
}
if input[i..].starts_with("!~") {
out.push(Token {
kind: TokenKind::Op(BinOp::NotContains),
offset: start,
});
i += 2;
continue;
}
return Err(BqlError::new(start, "stray '!' (expected an operator)"));
}
'$' => {
if input[i..].starts_with("$=") {
out.push(Token {
kind: TokenKind::Op(BinOp::EndsWith),
offset: start,
});
i += 2;
continue;
}
return Err(BqlError::new(start, "stray '$' (expected an operator)"));
}
'<' => {
if input[i..].starts_with("<=") {
out.push(Token {
kind: TokenKind::Op(BinOp::Lte),
offset: start,
});
i += 2;
continue;
}
if input[i..].starts_with("<") {
out.push(Token {
kind: TokenKind::Op(BinOp::Lt),
offset: start,
});
i += 1;
continue;
}
return Err(BqlError::new(start, "stray '<' (expected an operator)"));
}
'=' => {
if input[i..].starts_with("=") {
out.push(Token {
kind: TokenKind::Op(BinOp::Eq),
offset: start,
});
i += 1;
continue;
}
return Err(BqlError::new(start, "stray '=' (expected an operator)"));
}
'>' => {
if input[i..].starts_with(">=") {
out.push(Token {
kind: TokenKind::Op(BinOp::Gte),
offset: start,
});
i += 2;
continue;
}
if input[i..].starts_with(">") {
out.push(Token {
kind: TokenKind::Op(BinOp::Gt),
offset: start,
});
i += 1;
continue;
}
return Err(BqlError::new(start, "stray '>' (expected an operator)"));
}
'^' => {
if input[i..].starts_with("^=") {
out.push(Token {
kind: TokenKind::Op(BinOp::StartsWith),
offset: start,
});
i += 2;
continue;
}
return Err(BqlError::new(start, "stray '^' (expected an operator)"));
}
'~' => {
if input[i..].starts_with("~") {
out.push(Token {
kind: TokenKind::Op(BinOp::Contains),
offset: start,
});
i += 1;
continue;
}
return Err(BqlError::new(start, "stray '~' (expected an operator)"));
}
')' => {
out.push(Token {
kind: TokenKind::RParen,
offset: start,
});
i += 1;
}
'"' => {
let (s, end) = lex_string(input, start)?;
out.push(Token {
kind: TokenKind::Str(s),
offset: start,
});
i = end;
}
_ => {
if !is_word_char(c) {
return Err(BqlError::new(start, format!("unexpected character `{c}`")));
}
let (w, end) = lex_word(input, i);
out.push(Token {
kind: TokenKind::Word(w),
offset: start,
});
i = end;
}
}
}
out.push(Token {
kind: TokenKind::Eof,
offset: n,
});
Ok(out)
}
fn is_word_char(c: char) -> bool {
matches!(c, 'A'..='Z' | 'a'..='z' | '0'..='9' | '_' | '-' | ':' | '.' | '+')
}
fn is_whitespace_char(c: char) -> bool {
matches!(c, ' ' | '\t' | '\r' | '\n')
}
#[allow(clippy::needless_lifetimes)]
fn lex_word<'a>(input: &'a str, start: usize) -> (&'a str, usize) {
let mut end = start;
for (off, c) in input[start..].char_indices() {
if is_word_char(c) {
end = start + off + c.len_utf8();
} else {
break;
}
}
(&input[start..end], end)
}
#[allow(clippy::needless_lifetimes)]
fn lex_string<'a>(input: &'a str, start: usize) -> BqlResult<(&'a str, usize)> {
let mut i = start + 1;
let n = input.len();
while i < n {
let c = input[i..].chars().next().expect("in-bounds");
if c == '"' {
return Ok((&input[start + 1..i], i + 1));
}
if c == '\\' {
i += 1;
if i >= n {
return Err(BqlError::new(start, "unterminated string literal"));
}
let e = input[i..].chars().next().expect("in-bounds");
match e {
'"' | '\\' | '/' | 'n' | 't' | 'r' | 'b' | 'f' => {}
'u' => {
let hex: Vec<char> = input[i + 1..].chars().take(4).collect();
if hex.len() < 4 {
return Err(BqlError::new(
start,
"incomplete `\\u` escape in string literal",
));
}
if !hex.iter().all(char::is_ascii_hexdigit) {
return Err(BqlError::new(
start,
"invalid `\\u` escape in string literal",
));
}
i += 5;
continue;
}
other => {
return Err(BqlError::new(
i,
format!("invalid escape sequence `\\{other}` in string literal"),
));
}
}
i += e.len_utf8();
} else {
i += c.len_utf8();
}
}
Err(BqlError::new(start, "unterminated string literal"))
}