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parser: improve error reporting for malformed literals #1162

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Merged
kodiakhq merged 1 commit into from
May 22, 2026
Merged

parser: improve error reporting for malformed literals #1162

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19 changes: 13 additions & 6 deletions crates/squawk_lexer/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -311,13 +311,14 @@ impl Cursor<'_> {
match self.first() {
'.' => self.eat_fractional(base),
'e' | 'E' => {
let exponent_start = self.pos_within_token();
self.bump();
let empty_exponent = !self.eat_numeric_exponent();
let empty_exponent_start = (!self.eat_numeric_exponent()).then_some(exponent_start);
let trailing_junk_start = self.pos_within_token();
self.eat_identifier();
LiteralKind::Numeric {
base,
empty_exponent,
empty_exponent_start,
trailing_junk_start,
}
}
Expand Down Expand Up @@ -504,21 +505,27 @@ impl Cursor<'_> {
// might have stuff after the ., and if it does, it needs to start
// with a number
self.bump();
let mut empty_exponent = false;
let mut empty_exponent_start = None;
if self.first().is_ascii_digit() {
self.eat_decimal_digits();
match self.first() {
'e' | 'E' => {
let exponent_start = self.pos_within_token();
self.bump();
empty_exponent = !self.eat_numeric_exponent();
if !self.eat_numeric_exponent() {
empty_exponent_start = Some(exponent_start);
}
}
_ => (),
}
} else {
match self.first() {
'e' | 'E' => {
let exponent_start = self.pos_within_token();
self.bump();
empty_exponent = !self.eat_numeric_exponent();
if !self.eat_numeric_exponent() {
empty_exponent_start = Some(exponent_start);
}
}
_ => (),
}
Expand All @@ -527,7 +534,7 @@ impl Cursor<'_> {
self.eat_identifier();
LiteralKind::Numeric {
base,
empty_exponent,
empty_exponent_start,
trailing_junk_start,
}
}
Expand Down
20 changes: 10 additions & 10 deletions crates/squawk_lexer/src/snapshots/squawk_lexer__tests__numeric.snap
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Expand Up @@ -6,24 +6,24 @@ expression: "lex(r#\"\n42\n3.5\n4.\n.001\n.123e10\n5e2\n1.925e-3\n1e-10\n1e+10\n
"\n" @ Whitespace,
"42" @ Literal { kind: Int { base: Decimal, empty_int: false, trailing_junk_start: 2 } },
"\n" @ Whitespace,
"3.5" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 3 } },
"3.5" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 3 } },
"\n" @ Whitespace,
"4." @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 2 } },
"4." @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 2 } },
"\n" @ Whitespace,
".001" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 4 } },
".001" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 4 } },
"\n" @ Whitespace,
".123e10" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 7 } },
".123e10" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 7 } },
"\n" @ Whitespace,
"5e2" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 3 } },
"5e2" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 3 } },
"\n" @ Whitespace,
"1.925e-3" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 8 } },
"1.925e-3" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 8 } },
"\n" @ Whitespace,
"1e-10" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 5 } },
"1e-10" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 5 } },
"\n" @ Whitespace,
"1e+10" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 5 } },
"1e+10" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 5 } },
"\n" @ Whitespace,
"1e10" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 4 } },
"1e10" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 4 } },
"\n" @ Whitespace,
"4664.E+5" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 8 } },
"4664.E+5" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 8 } },
"\n" @ Whitespace,
]
2 changes: 1 addition & 1 deletion crates/squawk_lexer/src/snapshots/squawk_lexer__tests__numeric_with_seperators.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,6 @@ expression: "lex(r#\"\n1_500_000_000\n0b10001000_00000000\n0o_1_755\n0xFFFF_FFFF
"\n" @ Whitespace,
"0xFFFF_FFFF" @ Literal { kind: Int { base: Hexadecimal, empty_int: false, trailing_junk_start: 11 } },
"\n" @ Whitespace,
"1.618_034" @ Literal { kind: Numeric { base: Decimal, empty_exponent: false, trailing_junk_start: 9 } },
"1.618_034" @ Literal { kind: Numeric { base: Decimal, empty_exponent_start: None, trailing_junk_start: 9 } },
"\n" @ Whitespace,
]
4 changes: 3 additions & 1 deletion crates/squawk_lexer/src/token.rs
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Expand Up @@ -137,7 +137,9 @@ pub enum LiteralKind {
/// see: <https://www.postgresql.org/docs/16/sql-syntax-lexical.html#SQL-SYNTAX-CONSTANTS-NUMERIC>
Numeric {
base: Base,
empty_exponent: bool,
// e.g., `1e` instead of `1e10`
empty_exponent_start: Option<u32>,
// e.g., `1foo` where `foo` is the junk
trailing_junk_start: u32,
},
/// String, e.g., `'foo'`
Expand Down
41 changes: 27 additions & 14 deletions crates/squawk_parser/src/lexed_str.rs
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Expand Up @@ -15,7 +15,7 @@ pub struct LexedStr<'a> {

struct LexError {
msg: String,
token: u32,
range: ops::Range<u32>,
}

impl<'a> LexedStr<'a> {
Expand Down Expand Up @@ -105,10 +105,10 @@ impl<'a> LexedStr<'a> {
// Some(self.error[err].msg.as_str())
// }

pub fn errors(&self) -> impl Iterator<Item = (usize, &str)> + '_ {
pub fn errors(&self) -> impl Iterator<Item = (ops::Range<u32>, &str)> + '_ {
self.error
.iter()
.map(|it| (it.token as usize, it.msg.as_str()))
.map(|it| (it.range.clone(), it.msg.as_str()))
}

fn push(&mut self, kind: SyntaxKind, offset: usize) {
Expand Down Expand Up @@ -140,14 +140,16 @@ impl<'a> Converter<'a> {
self.res
}

fn push(&mut self, kind: SyntaxKind, len: usize, err: Option<&str>) {
fn push(&mut self, kind: SyntaxKind, len: usize, err: Option<(&str, ops::Range<u32>)>) {
let token_start = self.offset as u32;
self.res.push(kind, self.offset);
self.offset += len;

if let Some(err) = err {
let token = self.res.len() as u32;
let msg = err.to_owned();
self.res.error.push(LexError { msg, token });
if let Some((msg, err_range)) = err {
self.res.error.push(LexError {
msg: msg.to_owned(),
range: token_start + err_range.start..token_start + err_range.end,
});
}
}

Expand All @@ -157,6 +159,7 @@ impl<'a> Converter<'a> {
// Storing that info in `SyntaxKind` is not possible due to its layout requirements of
// being `u16` that come from `rowan::SyntaxKind`.
let mut err = "";
let mut err_range: Option<ops::Range<u32>> = None;

let syntax_kind = {
match kind {
Expand Down Expand Up @@ -214,6 +217,7 @@ impl<'a> Converter<'a> {
} => {
if (*trailing_junk_start as usize) < token_text.len() {
err = "trailing junk after positional parameter";
err_range = Some(*trailing_junk_start..token_text.len() as u32);
}
SyntaxKind::POSITIONAL_PARAM
}
Expand All @@ -227,11 +231,13 @@ impl<'a> Converter<'a> {
};

let err = if err.is_empty() { None } else { Some(err) };
let err = err.map(|msg| (msg, err_range.unwrap_or(0..token_text.len() as u32)));
self.push(syntax_kind, token_text.len(), err);
}

fn extend_literal(&mut self, token_text: &str, kind: &squawk_lexer::LiteralKind) {
let mut err: Option<String> = None;
let mut err_range: Option<ops::Range<u32>> = None;

let syntax_kind = match *kind {
squawk_lexer::LiteralKind::Int {
Expand All @@ -243,18 +249,21 @@ impl<'a> Converter<'a> {
err = Some("Missing digits after the integer base prefix".into());
} else if (trailing_junk_start as usize) < token_text.len() {
err = Some("trailing junk after numeric literal".into());
err_range = Some(trailing_junk_start..token_text.len() as u32);
}
SyntaxKind::INT_NUMBER
}
squawk_lexer::LiteralKind::Numeric {
empty_exponent,
empty_exponent_start,
base: _,
trailing_junk_start,
} => {
if empty_exponent {
if let Some(exponent_start) = empty_exponent_start {
err = Some("Missing digits after the exponent symbol".into());
err_range = Some(exponent_start..exponent_start + 1);
} else if (trailing_junk_start as usize) < token_text.len() {
err = Some("trailing junk after numeric literal".into());
err_range = Some(trailing_junk_start..token_text.len() as u32);
}
SyntaxKind::NUMERIC_NUMBER
}
Expand Down Expand Up @@ -312,7 +321,10 @@ impl<'a> Converter<'a> {
}
};

self.push(syntax_kind, token_text.len(), err.as_deref());
let err = err
.as_deref()
.map(|msg| (msg, err_range.unwrap_or(0..token_text.len() as u32)));
self.push(syntax_kind, token_text.len(), err);
}
}

Expand All @@ -328,11 +340,12 @@ mod tests {
let renderer = Renderer::plain().decor_style(DecorStyle::Unicode);
let mut res = String::new();

for (token, msg) in lexed.errors() {
for (range, msg) in lexed.errors() {
let span = range.start as usize..range.end as usize;
let group = Level::ERROR.primary_title(msg).element(
Snippet::source(text)
.fold(true)
.annotation(AnnotationKind::Primary.span(lexed.text_range(token))),
.annotation(AnnotationKind::Primary.span(span)),
);
res.push_str(&renderer.render(&[group]).to_string());
res.push('\n');
Expand All @@ -357,7 +370,7 @@ mod tests {
error: Missing digits after the exponent symbol
╭▸
1 │ select 1e;
╰╴ ━━
╰╴ ━
");
}

Expand Down
50 changes: 25 additions & 25 deletions crates/squawk_parser/tests/snapshots/tests__select_literal_err.snap
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Expand Up @@ -273,108 +273,108 @@ SOURCE_FILE
error[syntax-error]: trailing junk after numeric literal
╭▸
1 │ SELECT 123abc;
╰╴ ━
╰╴ ━━━
error[syntax-error]: trailing junk after numeric literal
╭▸
2 │ SELECT 0x0o;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
3 │ SELECT 0.a;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
4 │ SELECT 0.0a;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
5 │ SELECT .0a;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
6 │ SELECT 0.0e1a;
╰╴ ━
╰╴ ━
error[syntax-error]: Missing digits after the exponent symbol
╭▸
7 │ SELECT 0.0e;
╰╴ ━
╰╴ ━
error[syntax-error]: Missing digits after the exponent symbol
╭▸
8 │ SELECT 0.0e+a;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after positional parameter
╭▸
9 │ SELECT $1a;
╰╴ ━
╰╴ ━
error[syntax-error]: Missing digits after the integer base prefix
╭▸
10 │ SELECT 0b;
╰╴ ━
╰╴ ━━
error[syntax-error]: trailing junk after numeric literal
╭▸
11 │ SELECT 1b;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
12 │ SELECT 0b0x;
╰╴ ━
╰╴ ━
error[syntax-error]: Missing digits after the integer base prefix
╭▸
13 │ SELECT 0o;
╰╴ ━
╰╴ ━━
error[syntax-error]: trailing junk after numeric literal
╭▸
14 │ SELECT 1o;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
15 │ SELECT 0o0x;
╰╴ ━
╰╴ ━
error[syntax-error]: Missing digits after the integer base prefix
╭▸
16 │ SELECT 0x;
╰╴ ━
╰╴ ━━
error[syntax-error]: trailing junk after numeric literal
╭▸
17 │ SELECT 1x;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
18 │ SELECT 0x0y;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
19 │ SELECT 100_;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
20 │ SELECT 100__000;
╰╴ ━
╰╴ ━━━━━
error[syntax-error]: missing comma
╭▸
21 │ SELECT _1_000.5;
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
22 │ SELECT 1_000_.5;
╰╴ ━
╰╴ ━
error[syntax-error]: missing comma
╭▸
22 │ SELECT 1_000_.5;
╰╴ ━
error[syntax-error]: trailing junk after numeric literal
╭▸
23 │ SELECT 1_000._5;
╰╴ ━
╰╴ ━━
error[syntax-error]: trailing junk after numeric literal
╭▸
24 │ SELECT 1_000.5_;
╰╴ ━
╰╴ ━
error[syntax-error]: Missing digits after the exponent symbol
╭▸
25 │ SELECT 1_000.5e_1;
╰╴ ━
╰╴ ━
error[syntax-error]: trailing junk after positional parameter
╭▸
26 │ SELECT $0_1;
╰╴ ━
╰╴ ━━
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