v/vlib/strconv/atof_test.v

import strconv
/**********************************************************************
*
* String to float Test
*
**********************************************************************/

fn test_atof() {
	//
	// test set
	//

	// float64
	src_num := [
		f64(0.3),
		-0.3,
		0.004,
		-0.004,
		0.0,
		-0.0,
		31234567890123
	]

	// strings
	src_num_str := [
		'0.3',
		'-0.3',
		'0.004',
		'-0.004',
		'0.0',
		'-0.0',
		'31234567890123',
	]

	// check conversion case 1 string <=> string
	for c,x in src_num {
		// slow atof
		assert strconv.atof64(src_num_str[c]).strlong() == x.strlong()


		// quick atof
		mut s1 := (strconv.atof_quick(src_num_str[c]).str())
		mut s2 := (x.str())
		delta := s1.f64() - s2.f64()
		//println("$s1 $s2 $delta")
		assert delta < f64(1e-16)

		// test C.atof
		n1 := x.strsci(18)
		n2 := f64(C.atof(src_num_str[c].str)).strsci(18)
		//println("$n1 $n2")
		assert n1 == n2
	}

	// check conversion case 2 string <==> f64
	// we don't test atof_quick beacuse we already know the rounding error
	for c,x  in src_num_str {
		b := src_num[c].strlong()
		a1 := strconv.atof64(x).strlong()
		assert a1 == b
	}

	// special cases
	mut f1 := f64(0.0)
	mut ptr := unsafe {&u64(&f1)}
	ptr = unsafe {&u64(&f1)}

	// double_plus_zero
	f1=0.0
	assert *ptr == u64(0x0000000000000000)
	// double_minus_zero
	f1=-0.0
	assert *ptr == u64(0x8000000000000000)
	println("DONE!")
}