use crate ::{
Literal, ParseError,
test_util::{assert_parse_ok_eq, assert_roundtrip},
};
use super ::{FloatLit, FloatType};
// ===== Utility functions =======================================================================
/// Helper macro to check parsing a float.
///
/// This macro contains quite a bit of logic itself (which can be buggy of
/// course), so we have a few test functions below to test a bunch of cases
/// manually.
macro_rules! check {
($intpart:literal $fracpart:literal $exppart:literal $suffix:tt) => {
let input = concat!($intpart, $fracpart, $exppart, check!(@stringify_suffix $suffix));
let expected_float = FloatLit {
raw: input,
end_integer_part: $intpart.len(),
end_fractional_part: $intpart.len() + $fracpart.len(),
end_number_part: $intpart.len() + $fracpart.len() + $exppart.len(),
};
assert_parse_ok_eq(
input, FloatLit::parse(input), expected_float.clone(), "FloatLit::parse" );
assert_parse_ok_eq(
input, Literal::parse(input), Literal::Float(expected_float), "Literal::parse" );
assert_eq!(FloatLit::parse(input).unwrap().suffix(), check!(@ty $suffix));
assert_roundtrip(expected_float.to_owned(), input);
};
(@ty f32) => { "f32" };
(@ty f64) => { "f64" };
(@ty -) => { "" };
(@stringify_suffix -) => { "" };
(@stringify_suffix $suffix:ident) => { stringify!($suffix) };
}
// ===== Actual tests ===========================================================================
#[ test]
fn manual_without_suffix() -> Result<(), ParseError> {
let f = FloatLit::parse("3.14" )?;
assert_eq!(f.number_part(), "3.14" );
assert_eq!(f.integer_part(), "3" );
assert_eq!(f.fractional_part(), Some("14" ));
assert_eq!(f.exponent_part(), "" );
assert_eq!(f.suffix(), "" );
let f = FloatLit::parse("9." )?;
assert_eq!(f.number_part(), "9." );
assert_eq!(f.integer_part(), "9" );
assert_eq!(f.fractional_part(), Some("" ));
assert_eq!(f.exponent_part(), "" );
assert_eq!(f.suffix(), "" );
let f = FloatLit::parse("8e1" )?;
assert_eq!(f.number_part(), "8e1" );
assert_eq!(f.integer_part(), "8" );
assert_eq!(f.fractional_part(), None);
assert_eq!(f.exponent_part(), "e1" );
assert_eq!(f.suffix(), "" );
let f = FloatLit::parse("8E3" )?;
assert_eq!(f.number_part(), "8E3" );
assert_eq!(f.integer_part(), "8" );
assert_eq!(f.fractional_part(), None);
assert_eq!(f.exponent_part(), "E3" );
assert_eq!(f.suffix(), "" );
let f = FloatLit::parse("8_7_6.1_23e15" )?;
assert_eq!(f.number_part(), "8_7_6.1_23e15" );
assert_eq!(f.integer_part(), "8_7_6" );
assert_eq!(f.fractional_part(), Some("1_23" ));
assert_eq!(f.exponent_part(), "e15" );
assert_eq!(f.suffix(), "" );
let f = FloatLit::parse("8.2e-_04_9" )?;
assert_eq!(f.number_part(), "8.2e-_04_9" );
assert_eq!(f.integer_part(), "8" );
assert_eq!(f.fractional_part(), Some("2" ));
assert_eq!(f.exponent_part(), "e-_04_9" );
assert_eq!(f.suffix(), "" );
Ok(())
}
#[ test]
fn manual_with_suffix() -> Result<(), ParseError> {
let f = FloatLit::parse("3.14f32" )?;
assert_eq!(f.number_part(), "3.14" );
assert_eq!(f.integer_part(), "3" );
assert_eq!(f.fractional_part(), Some("14" ));
assert_eq!(f.exponent_part(), "" );
assert_eq!(FloatType::from_suffix(f.suffix()), Some(FloatType::F32));
let f = FloatLit::parse("8e1f64" )?;
assert_eq!(f.number_part(), "8e1" );
assert_eq!(f.integer_part(), "8" );
assert_eq!(f.fractional_part(), None);
assert_eq!(f.exponent_part(), "e1" );
assert_eq!(FloatType::from_suffix(f.suffix()), Some(FloatType::F64));
let f = FloatLit::parse("8_7_6.1_23e15f32" )?;
assert_eq!(f.number_part(), "8_7_6.1_23e15" );
assert_eq!(f.integer_part(), "8_7_6" );
assert_eq!(f.fractional_part(), Some("1_23" ));
assert_eq!(f.exponent_part(), "e15" );
assert_eq!(FloatType::from_suffix(f.suffix()), Some(FloatType::F32));
let f = FloatLit::parse("8.2e-_04_9f64" )?;
assert_eq!(f.number_part(), "8.2e-_04_9" );
assert_eq!(f.integer_part(), "8" );
assert_eq!(f.fractional_part(), Some("2" ));
assert_eq!(f.exponent_part(), "e-_04_9" );
assert_eq!(FloatType::from_suffix(f.suffix()), Some(FloatType::F64));
Ok(())
}
#[ test]
fn simple() {
check!("3" ".14" "" -);
check!("3" ".14" "" f32);
check!("3" ".14" "" f64);
check!("3" "" "e987654321" -);
check!("3" "" "e987654321" f64);
check!("42_888" ".05" "" -);
check!("42_888" ".05" "E5___" f32);
check!("123456789" "" "e_1" f64);
check!("123456789" ".99" "e_1" f64);
check!("123456789" ".99" "" f64);
check!("123456789" ".99" "" -);
check!("147" ".3_33" "" -);
check!("147" ".3_33__" "E3" f64);
check!("147" ".3_33__" "" f32);
check!("147" ".333" "e-10" -);
check!("147" ".333" "e-_7" f32);
check!("147" ".333" "e+10" -);
check!("147" ".333" "e+_7" f32);
check!("86" "." "" -);
check!("0" "." "" -);
check!("0_" "." "" -);
check!("0" ".0000001" "" -);
check!("0" ".000_0001" "" -);
check!("0" ".0" "e+0" -);
check!("0" "" "E+0" -);
check!("34" "" "e+0" -);
check!("0" ".9182" "E+0" f32);
}
#[ test]
fn non_standard_suffixes() {
#[ track_caller]
fn check_suffix(
input: &str,
integer_part: &str,
fractional_part: Option<&str>,
exponent_part: &str,
suffix: &str,
) {
let lit = FloatLit::parse(input)
.unwrap_or_else(|e| panic!("expected to parse '{}' but got {}" , input, e));
assert_eq!(lit.integer_part(), integer_part);
assert_eq!(lit.fractional_part(), fractional_part);
assert_eq!(lit.exponent_part(), exponent_part);
assert_eq!(lit.suffix(), suffix);
let lit = match Literal::parse(input) {
Ok(Literal::Float(f)) => f,
other => panic!("Expected float literal, but got {:?} for '{}'" , other, input),
};
assert_eq!(lit.integer_part(), integer_part);
assert_eq!(lit.fractional_part(), fractional_part);
assert_eq!(lit.exponent_part(), exponent_part);
assert_eq!(lit.suffix(), suffix);
}
check_suffix("7.1f23" , "7" , Some("1" ), "" , "f23" );
check_suffix("7.1f320" , "7" , Some("1" ), "" , "f320" );
check_suffix("7.1f64_" , "7" , Some("1" ), "" , "f64_" );
check_suffix("8.1f649" , "8" , Some("1" ), "" , "f649" );
check_suffix("8.1f64f32" , "8" , Some("1" ), "" , "f64f32" );
check_suffix("23e2_banana" , "23" , None, "e2_" , "banana" );
check_suffix("23.2_banana" , "23" , Some("2_" ), "" , "banana" );
check_suffix("23e2pe55ter" , "23" , None, "e2" , "pe55ter" );
check_suffix("23e2p_e55ter" , "23" , None, "e2" , "p_e55ter" );
check_suffix("3.15Jürgen" , "3" , Some("15" ), "" , "Jürgen" );
check_suffix("3e2e5" , "3" , None, "e2" , "e5" );
check_suffix("3e2e5f" , "3" , None, "e2" , "e5f" );
}
#[ test]
fn parse_err() {
assert_err!(FloatLit, "" , Empty, None);
assert_err_single!(FloatLit::parse("." ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("+" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("-" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("e" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("e8" ), DoesNotStartWithDigit, 0 );
assert_err!(FloatLit, "0e" , NoExponentDigits, 1 ..2 );
assert_err_single!(FloatLit::parse("f32" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("foo" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("inf" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("nan" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("NaN" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("NAN" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse("_2.7" ), DoesNotStartWithDigit, 0 );
assert_err_single!(FloatLit::parse(".5" ), DoesNotStartWithDigit, 0 );
assert_err!(FloatLit, "1e" , NoExponentDigits, 1 ..2 );
assert_err!(FloatLit, "1.e4" , UnexpectedChar, 2 );
assert_err!(FloatLit, "3._4" , UnexpectedChar, 2 );
assert_err!(FloatLit, "3.f32" , UnexpectedChar, 2 );
assert_err!(FloatLit, "3.e5" , UnexpectedChar, 2 );
assert_err!(FloatLit, "12345._987" , UnexpectedChar, 6 );
assert_err!(FloatLit, "46._" , UnexpectedChar, 3 );
assert_err!(FloatLit, "46.f32" , UnexpectedChar, 3 );
assert_err!(FloatLit, "46.e3" , UnexpectedChar, 3 );
assert_err!(FloatLit, "46._e3" , UnexpectedChar, 3 );
assert_err!(FloatLit, "46.e3f64" , UnexpectedChar, 3 );
assert_err!(FloatLit, "23.4e_" , NoExponentDigits, 4 ..6 );
assert_err!(FloatLit, "23E___f32" , NoExponentDigits, 2 ..6 );
assert_err!(FloatLit, "55e3.1" , UnexpectedChar, 4 ..6 );
assert_err!(FloatLit, "3.7+" , UnexpectedChar, 3 ..4 );
assert_err!(FloatLit, "3.7+2" , UnexpectedChar, 3 ..5 );
assert_err!(FloatLit, "3.7-" , UnexpectedChar, 3 ..4 );
assert_err!(FloatLit, "3.7-2" , UnexpectedChar, 3 ..5 );
assert_err!(FloatLit, "3.7e+" , NoExponentDigits, 3 ..5 );
assert_err!(FloatLit, "3.7e-" , NoExponentDigits, 3 ..5 );
assert_err!(FloatLit, "3.7e-+3" , NoExponentDigits, 3 ..5 ); // suboptimal error
assert_err!(FloatLit, "3.7e+-3" , NoExponentDigits, 3 ..5 ); // suboptimal error
assert_err_single!(FloatLit::parse("0x44.5" ), InvalidSuffix, 1 ..6 );
assert_err_single!(FloatLit::parse("3" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("35_389" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("9_8_7f32" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("9_8_7banana" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("7f23" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("7f320" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("7f64_" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("8f649" ), UnexpectedIntegerLit, None);
assert_err_single!(FloatLit::parse("8f64f32" ), UnexpectedIntegerLit, None);
}
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¤ Dauer der Verarbeitung: 0.12 Sekunden
(vorverarbeitet am 2026-06-19)
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