README
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Refloat
Float parser that sacrifices nothing.
Features
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Accurate. It finds the "best" approximation to the input just like the standard library, strconv. Fuzzing tests in addition to standard library tests and parse-number-fxx-test-data are actively done.
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Compatible. Basically, it is an improvement on
ParseFloatin the standard library, and the usage is exactly the same. -
Fast. Faster than the standard library on benchmarks with normally distributed floats and bitwise uniform random float inputs. For more information, benchmark it yourself or see below.
Installation
go get github.com/sugawarayuuta/refloat
Benchmarks
gantt
title norm = normally distributed, bits = bitwise uniform (ns/op - lower is better)
todayMarker off
dateFormat X
axisFormat %s
section bits 64bit
strconv: 0,106
refloat: 0,91
section norm 64bit
strconv: 0,92
refloat: 0,65
section bits 32bit
strconv: 0,79
refloat: 0,80
section norm 32bit
strconv: 0,65
refloat: 0,49
Articles
There are articles written in English and Japanese.
Thank you
The icon above is from gopher-stickers by Ueda Takuya.
Awesome talk and inspirational algorithm by Daniel Lemire.
Sollya is used for precomputing the polynomial for approximations.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrRange indicates that a value is out of range for the target type. ErrRange = errors.New("value out of range") // ErrSyntax indicates that a value does not have the right syntax for the target type. ErrSyntax = errors.New("invalid syntax") )
Functions ¶
func ParseFloat ¶
ParseFloat converts the string num to a floating-point number with the precision specified by size: 32 for float32, or 64 for float64. When size=32, the result still has type float64, but it will be convertible to float32 without changing its value.
ParseFloat accepts decimal and hexadecimal floating-point numbers as defined by the Go syntax for floating-point literals. If num is well-formed and near a valid floating-point number, ParseFloat returns the nearest floating-point number rounded using IEEE754 unbiased rounding. (Parsing a hexadecimal floating-point value only rounds when there are more bits in the hexadecimal representation than will fit in the mantissa.)
The errors that ParseFloat returns have concrete type *NumError and include err.Num = num.
If num is not syntactically well-formed, ParseFloat returns err.Err = ErrSyntax.
If num is syntactically well-formed but is more than 1/2 ULP away from the largest floating point number of the given size, ParseFloat returns f = ±Inf, err.Err = ErrRange.
ParseFloat recognizes the string "NaN", and the (possibly signed) strings "Inf" and "Infinity" as their respective special floating point values. It ignores case when matching.
Source Files