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/**********************************************************************
*
* Float to string Test
*
**********************************************************************/
import strconv
import math
union Ufloat32 {
mut:
f f32 = f32(0)
b u32
}
union Ufloat64 {
mut:
f f64 = f64(0)
b u64
}
fn f64_from_bits1(b u64) f64 {
mut x := Ufloat64{}
x.b = b
// C.printf("bin: %016llx\n",x.f)
return unsafe { x.f }
}
fn f32_from_bits1(b u32) f32 {
mut x := Ufloat32{}
x.b = b
// C.printf("bin: %08x\n",x.f)
return unsafe { x.f }
}
fn test_float_to_str() {
test_cases_f32 := [
f32_from_bits1(0x0000_0000), // +0
f32_from_bits1(0x8000_0000), // -0
f32_from_bits1(0xFFC0_0001), // sNan
f32_from_bits1(0xFF80_0001), // qNan
f32_from_bits1(0x7F80_0000), // +inf
f32_from_bits1(0xFF80_0000), // -inf
1,
-1,
10,
-10,
0.3,
-0.3,
1000000,
123456.7,
123e35,
-123.45,
1e23,
f32_from_bits1(0x0080_0000), // smallest float32
math.max_f32,
383260575764816448.0,
]
exp_result_f32 := [
'0e+00',
'-0e+00',
'nan',
'nan',
'+inf',
'-inf',
'1.e+00',
'-1.e+00',
'1.e+01',
'-1.e+01',
'3.e-01',
'-3.e-01',
'1.e+06',
'1.234567e+05',
'1.23e+37',
'-1.2345e+02',
'1.e+23',
'1.1754944e-38', // aprox from 1.1754943508 × 10−38,
'3.4028235e+38',
'3.8326058e+17',
]
test_cases_f64 := [
f64_from_bits1(0x0000_0000_0000_0000), // +0
f64_from_bits1(0x8000_0000_0000_0000), // -0
f64_from_bits1(0x7FF0_0000_0000_0001), // sNan
f64_from_bits1(0x7FF8_0000_0000_0001), // qNan
f64_from_bits1(0x7FF0_0000_0000_0000), // +inf
f64_from_bits1(0xFFF0_0000_0000_0000), // -inf
1,
-1,
10,
-10,
0.3,
-0.3,
1000000,
123456.7,
123e45,
-123.45,
1e23,
f64_from_bits1(0x0010_0000_0000_0000), // smallest float64
math.max_f32,
383260575764816448,
383260575764816448,
// C failing cases
123e300,
123e-300,
5.e-324,
-5.e-324,
]
exp_result_f64 := [
'0e+00',
'-0e+00',
'nan',
'nan',
'+inf',
'-inf',
'1.e+00',
'-1.e+00',
'1.e+01',
'-1.e+01',
'3.e-01',
'-3.e-01',
'1.e+06',
'1.234567e+05',
'1.23e+47',
'-1.2345e+02',
'1.e+23',
'2.2250738585072014e-308',
'3.4028234663852886e+38',
'3.8326057576481645e+17',
'3.8326057576481645e+17',
'1.23e+302', // this test is failed from C sprintf!!
'1.23e-298',
'5.e-324',
'-5.e-324',
]
// test f32
for c, x in test_cases_f32 {
println(x)
s := strconv.f32_to_str(x, 8)
s1 := exp_result_f32[c]
// println("$s1 $s")
assert s == s1
}
// test f64
for c, x in test_cases_f64 {
s := strconv.f64_to_str(x, 17)
s1 := exp_result_f64[c]
// println("$s1 $s")
assert s == s1
}
// test long format
for exp := 1; exp < 120; exp++ {
a := strconv.f64_to_str_l(('1e' + exp.str()).f64())
// println(a)
assert a.len == exp + 1
b := strconv.f64_to_str_l(('1e-' + exp.str()).f64())
// println(b)
assert b.len == exp + 2
}
// test rounding str conversion
// println( ftoa.f64_to_str(0.3456789123456, 4) )
// assert ftoa.f64_to_str(0.3456789123456, 4)=="3.4568e-01"
// assert ftoa.f32_to_str(0.345678, 3)=="3.457e-01"
}
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