git.delta.rocks / jrsonnet / refs/commits / ecbe9eb36517

338		nums338		nums
339	} else {339	} else {
340		let (mantissa, exp) = decompose_f64(iv);340		let (mantissa, exp) = decompose_f64(iv);
341		let mut v = BigUint::from(mantissa) << u32::try_from(exp).expect("huge f64 exp fits u32");341		let mut v = BigUint::from(mantissa) << exp.unsigned_abs();
342		let radix = BigUint::from(radix as u64);342		let radix = BigUint::from(radix as u64);
343		let mut nums = Vec::new();343		let mut nums = Vec::new();
344		while v != BigUint::ZERO {344		while v != BigUint::ZERO {
526526
527/// bool signifies carry, e.g 0.999 at precision 2 results in 1.000, thus carry.527/// bool signifies carry, e.g 0.999 at precision 2 results in 1.000, thus carry.
528// floor((2 * low_bits * 10**prec + 2**k) / 2**(k+1))528// floor((2 * low_bits * 10**prec + 2**k) / 2**(k+1))
529fn round_frac(abs: f64, precision: u16) -> (Frac, bool) {529fn round_frac(abs: f64, prec: u16) -> (Frac, bool) {
530	let prec = usize::from(precision);
531	let (mantissa, exp) = decompose_f64(abs);530	let (mantissa, exp) = decompose_f64(abs);
532	if exp >= 0 {531	if exp >= 0 {
533		// abs is integral: no fractional bits.532		// abs is integral: no fractional bits.
534		return (Frac::Small(0), false);533		return (Frac::Small(0), false);
535	}534	}
536	let k = u32::try_from(-exp).expect("exp fits u32");535	let k = exp.unsigned_abs();
537	// Fractional part is exactly `low_bits / 2**k` (mantissa is 53 bits).536	// Fractional part is exactly `low_bits / 2**k` (mantissa is 53 bits).
538	let low_bits = if k >= 64 {537	let low_bits = if k >= 64 {
539		mantissa538		mantissa
546	round_frac_u128(low_bits, k, prec).unwrap_or_else(|| round_frac_big(low_bits, k, prec))545	round_frac_u128(low_bits, k, prec).unwrap_or_else(|| round_frac_big(low_bits, k, prec))
547}546}
548547
549fn round_frac_u128(low_bits: u64, k: u32, prec: usize) -> Option<(Frac, bool)> {548fn round_frac_u128(low_bits: u64, k: u32, prec: u16) -> Option<(Frac, bool)> {
550	if k > 126 {549	if k > 126 {
551		return None;550		return None;
552	}551	}
553	let mut ten_pow = 1u128;552	let ten_pow = 10u128.checked_pow(u32::from(prec))?;
554	for _ in 0..prec {
555		ten_pow = ten_pow.checked_mul(10)?;
556	}
557	let numerator = u128::from(low_bits)553	let numerator = u128::from(low_bits)
558		.checked_mul(ten_pow)?554		.checked_mul(ten_pow)?
559		.checked_mul(2)?555		.checked_mul(2)?
566	})562	})
567}563}
568564
569fn round_frac_big(low_bits: u64, k: u32, prec: usize) -> (Frac, bool) {565fn round_frac_big(low_bits: u64, k: u32, prec: u16) -> (Frac, bool) {
570	let mut ten_pow = BigUint::from(1u32);
571	let ten = BigUint::from(10u32);566	let ten_pow = BigUint::from(10u32).pow(u32::from(prec));
572	for _ in 0..prec {
573		ten_pow *= &ten;
574	}
575	let numerator = ((BigUint::from(low_bits) * &ten_pow) << 1u32) + (BigUint::from(1u32) << k);567	let frac = round_ratio(
576	let frac = numerator >> (k + 1);568		&(BigUint::from(low_bits) * &ten_pow),
569		&(BigUint::from(1u32) << k),
570	);
577	if frac == ten_pow {571	if frac == ten_pow {
578		(Frac::Small(0), true)572		(Frac::Small(0), true)
579	} else {573	} else {
580		(Frac::Big(frac), false)574		(Frac::Big(frac), false)
581	}575	}
582}576}
577
578fn round_ratio(num: &BigUint, den: &BigUint) -> BigUint {
579	((num << 1u32) + den) / (den << 1u32)
580}
581
582fn shorter_exponent(value: f64, sig: u16) -> i32 {
583	if value == 0.0 {
584		return 0;
585	}
586	let abs = value.abs();
587	let e0 = abs.log10().floor() as i32;
588	if rounds_up_to_next_pow10(abs, sig, e0) {
589		e0 + 1
590	} else {
591		e0
592	}
593}
594
595fn rounds_up_to_next_pow10(abs: f64, sig: u16, e0: i32) -> bool {
596	let (mantissa, exp) = decompose_f64(abs);
597	// abs * 10**(sig-1-e0) == num / den
598	let t = i32::from(sig) - 1 - e0;
599	let mut num = BigUint::from(mantissa);
600	let mut den = BigUint::from(1u32);
601	let exp_abs = exp.unsigned_abs();
602	if exp >= 0 {
603		num <<= exp_abs;
604	} else {
605		den <<= exp_abs;
606	}
607	let pow10_t_abs = BigUint::from(10u32).pow(t.unsigned_abs());
608	if t >= 0 {
609		num *= pow10_t_abs;
610	} else {
611		den *= pow10_t_abs;
612	}
613	round_ratio(&num, &den) >= BigUint::from(10u32).pow(u32::from(sig))
614}
583615
584#[allow(clippy::fn_params_excessive_bools)]616#[allow(clippy::fn_params_excessive_bools)]
585pub fn render_float_sci(617pub fn render_float_sci(
594	caps: bool,626	caps: bool,
595) {627) {
596	let exponent = if n == 0.0 {628	let exponent = if n == 0.0 {
597		0.0629		0
598	} else {630	} else {
599		n.abs().log10().floor()631		shorter_exponent(n, precision.saturating_add(1))
600	};632	};
601633
602	let mantissa = if exponent as i16 == -324 {634	let mantissa = if exponent == -324 {
603		n * 10.0 / 10.0_f64.powf(exponent + 1.0)635		n * 10.0 / 10.0_f64.powi(exponent + 1)
604	} else {636	} else {
605		n / 10.0_f64.powf(exponent)637		n / 10.0_f64.powi(exponent)
606	};638	};
607	let mut exponent_str = String::new();639	let mut exponent_str = String::new();
608	render_decimal(640	render_decimal(
609		&mut exponent_str,641		&mut exponent_str,
610		exponent < 0.0,642		exponent < 0,
611		exponent.abs(),643		f64::from(exponent.abs()),
612		3,644		3,
613		0,645		0,
614		false,646		false,
713		}745		}
714		ConvTypeV::Shorter => {746		ConvTypeV::Shorter => {
715			let value = f64::from_untyped(value.clone())?;747			let value = f64::from_untyped(value.clone())?;
716			let exponent = if value == 0.0 {748			let fpprec = fpprec.max(1);
717				0.0749			let exponent = shorter_exponent(value, fpprec);
718			} else {
719				value.abs().log10().floor()
720			};
721			if exponent < -4.0 || exponent >= f64::from(fpprec) {750			if exponent < -4 || exponent >= i32::from(fpprec) {
722				render_float_sci(751				render_float_sci(
723					&mut tmp_out,752					&mut tmp_out,
724					value,753					value,
731					code.caps,760					code.caps,
732				);761				);
733			} else {762			} else {
734				let digits_before_pt = 1.max(exponent as u16 + 1);763				let frac_prec = (i32::from(fpprec) - 1 - exponent).max(0) as u16;
735				render_float(764				render_float(
736					&mut tmp_out,765					&mut tmp_out,
737					value,766					value,
738					padding,767					padding,
739					fpprec - digits_before_pt,768					frac_prec,
740					clfags.blank,769					clfags.blank,
741					clfags.sign,770					clfags.sign,
742					clfags.alt,771					clfags.alt,