// Copyright (c) 2019-2023 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

pub const (
	epsilon      = 2.2204460492503130808472633361816E-16
	e            = 2.71828182845904523536028747135266249775724709369995957496696763
	pi           = 3.14159265358979323846264338327950288419716939937510582097494459
	pi_2         = pi / 2.0
	pi_4         = pi / 4.0
	phi          = 1.61803398874989484820458683436563811772030917980576286213544862
	tau          = 6.28318530717958647692528676655900576839433879875021164194988918
	one_over_tau = 1.0 / tau
	one_over_pi  = 1.0 / pi
	tau_over2    = tau / 2.0
	tau_over4    = tau / 4.0
	tau_over8    = tau / 8.0
	sqrt2        = 1.41421356237309504880168872420969807856967187537694807317667974
	sqrt_3       = 1.73205080756887729352744634150587236694280525381038062805580697
	sqrt_5       = 2.23606797749978969640917366873127623544061835961152572427089724
	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
	two_thirds   = 0.66666666666666666666666666666666666666666666666666666666666667
)

// 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.
pub 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
pub const (
	min_i8  = i8(-128)
	max_i8  = i8(127)
	min_i16 = i16(-32768)
	max_i16 = i16(32767)
	min_i32 = int(-2147483648)
	max_i32 = int(2147483647)
	// -9223372036854775808 is wrong, because C compilers parse literal values
	// without sign first, and 9223372036854775808 overflows i64, hence the
	// consecutive subtraction by 1
	min_i64 = i64(-9223372036854775807 - 1)
	max_i64 = i64(9223372036854775807)
	min_u8  = u8(0)
	max_u8  = u8(255)
	min_u16 = u16(0)
	max_u16 = u16(65535)
	min_u32 = u32(0)
	max_u32 = u32(4294967295)
	min_u64 = u64(0)
	max_u64 = u64(18446744073709551615)
)