math: new consts + helpers funcs for string to int / float

vlib/math/bits.v

@@ -0,0 +1,58 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module math
+
+const (
+	uvnan     = 0x7FF8000000000001
+	uvinf     = 0x7FF0000000000000
+	uvneginf  = 0xFFF0000000000000
+	uvone     = 0x3FF0000000000000
+	mask      = 0x7FF
+	shift     = 64 - 11 - 1
+	bias      = 1023
+	sign_mask = u64(u64(1) << 63)
+	frac_mask = u64(u64(u64(1)<<u64(shift)) - u64(1))
+)
+
+// inf returns positive infinity if sign >= 0, negative infinity if sign < 0.
+pub fn inf(sign int) f64 {
+	v := if sign >= 0 { uvinf } else { uvneginf }
+	return f64_from_bits(v)
+}
+
+// nan returns an IEEE 754 ``not-a-number'' value.
+pub fn nan() f64 { return f64_from_bits(uvnan) }
+
+// is_nan reports whether f is an IEEE 754 ``not-a-number'' value.
+pub fn is_nan(f f64) bool {
+	// IEEE 754 says that only NaNs satisfy f != f.
+	// To avoid the floating-point hardware, could use:
+	//	x := f64_bits(f);
+	//	return u32(x>>shift)&mask == mask && x != uvinf && x != uvneginf
+	return f != f
+}
+
+// is_inf reports whether f is an infinity, according to sign.
+// If sign > 0, is_inf reports whether f is positive infinity.
+// If sign < 0, is_inf reports whether f is negative infinity.
+// If sign == 0, is_inf reports whether f is either infinity.
+pub fn is_inf(f f64, sign int) bool {
+	// Test for infinity by comparing against maximum float.
+	// To avoid the floating-point hardware, could use:
+	//	x := f64_bits(f);
+	//	return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf;
+	return (sign >= 0 && f > max_f64) || (sign <= 0 && f < -max_f64)
+}
+
+// NOTE: (joe-c) exponent notation is borked
+// normalize returns a normal number y and exponent exp
+// satisfying x == y × 2**exp. It assumes x is finite and non-zero.
+// pub fn normalize(x f64) (f64, int) {
+// 	smallest_normal := 2.2250738585072014e-308 // 2**-1022
+// 	if abs(x) < smallest_normal {
+// 		return x * (1 << 52), -52
+// 	}
+// 	return x, 0
+// }

vlib/math/const.v

@@ -0,0 +1,50 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module math
+
+const (
+	e   = 2.71828182845904523536028747135266249775724709369995957496696763
+	pi  = 3.14159265358979323846264338327950288419716939937510582097494459
+	phi = 1.61803398874989484820458683436563811772030917980576286213544862
+	tau = 6.28318530717958647692528676655900576839433879875021164194988918
+
+	sqrt2   = 1.41421356237309504880168872420969807856967187537694807317667974
+	sqrt_e   = 1.64872127070012814684865078781416357165377610071014801157507931
+	sqrt_pi  = 1.77245385090551602729816748334114518279754945612238712821380779
+	sqrt_tau = 2.50662827463100050241576528481104525300698674060993831662992357
+	sqrt_phi = 1.27201964951406896425242246173749149171560804184009624861664038
+
+	ln2    = 0.693147180559945309417232121458176568075500134360255254120680009
+	log2_e  = 1.0 / ln2
+	ln10   = 2.30258509299404568401799145468436420760110148862877297603332790
+	log10_e = 1.0 / ln10
+)
+
+// Floating-point limit values
+// max is the largest finite value representable by the type.
+// smallest_non_zero is the smallest positive, non-zero value representable by the type.
+const (
+	max_f32               = 3.40282346638528859811704183484516925440e+38  // 2**127 * (2**24 - 1) / 2**23
+	smallest_non_zero_f32 = 1.401298464324817070923729583289916131280e-45 // 1 / 2**(127 - 1 + 23)
+
+	max_f64               = 1.797693134862315708145274237317043567981e+308 // 2**1023 * (2**53 - 1) / 2**52
+	smallest_non_zero_f64 = 4.940656458412465441765687928682213723651e-324 // 1 / 2**(1023 - 1 + 52)
+)
+
+// Integer limit values
+const (
+	max_i8  = 127
+	min_i8  = -128
+	max_i16 = 32767
+	min_i16 = -32768
+	max_i32 = 2147483647
+	min_i32 = -2147483648
+	min_i64 = -9223372036854775808
+	max_i64 = 9223372036854775807
+	max_u8  = 255
+	max_u16 = 65535
+	max_u32 = 4294967295
+	max_u64 = 18446744073709551615
+)

vlib/math/math.v

@@ -10,39 +10,6 @@ module math
 // When adding a new function, please make sure it's in the right place.
 // All functions are sorted alphabetically.
 
-const (
-	e   = 2.71828182845904523536028747135266249775724709369995957496696763
-	pi  = 3.14159265358979323846264338327950288419716939937510582097494459
-	phi = 1.61803398874989484820458683436563811772030917980576286213544862
-	tau = 6.28318530717958647692528676655900576839433879875021164194988918
-
-	sqrt2   = 1.41421356237309504880168872420969807856967187537694807317667974
-	sqrt_e   = 1.64872127070012814684865078781416357165377610071014801157507931
-	sqrt_pi  = 1.77245385090551602729816748334114518279754945612238712821380779
-	sqrt_tau = 2.50662827463100050241576528481104525300698674060993831662992357
-	sqrt_phi = 1.27201964951406896425242246173749149171560804184009624861664038
-
-	ln2    = 0.693147180559945309417232121458176568075500134360255254120680009
-	log2_e  = 1.0 / ln2
-	ln10   = 2.30258509299404568401799145468436420760110148862877297603332790
-	log10_e = 1.0 / ln10
-)
-
-const (
-        max_i8   = 127
-        min_i8   = -128
-        max_i16  = 32767
-        min_i16  = -32768
-        max_i32  = 2147483647
-        min_i32  = -2147483648
-//        MaxI64  = ((1<<63) - 1)
-//        MinI64  = (-(1 << 63) )
-        max_u8  = 255
-        max_u16 = 65535
-        max_u32 = 4294967295
-        max_u64 = 18446744073709551615
-)
-
 // Returns the absolute value.
 pub fn abs(a f64) f64 {
 	if a < 0 {