README
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decimals
Decimals is a small library of functions for rounding and formatting base ten numbers in Go. These are functions that are either missing from the standard libraries or are more convenient for presenting numbers in a human-readable format.
Version 2.0
In the original version of this package, integer rounding was performed with mathematical operations. This worked in most cases but produced incorrect results when rounding at or near the minimum and maximum int64 values. The latest version of the library provides the same public interface, but internally uses string representations of decimal numbers in order to produce consistent rounding behaviour across the full range of integer values. If you attempt to round to a number beyond the minimum or maximum int64 values the minimum or maximum is returned instead.
Installation
Install with go get.
go get github.com/olihawkins/decimals
Tests
Use go test to run the tests.
Documentation
See the GoDoc for the full documentation.
Rounding
Round int64 and float64 numbers.
decimals.RoundInt(x int64, precision int) int64
decimals.RoundFloat(x float64, precision int) float64
Round an integer to the nearest power of ten using a negative value for precision.
i := decimals.RoundInt(555, 0) // i = 555
i := decimals.RoundInt(555, -1) // i = 560
i := decimals.RoundInt(555, -2) // i = 600
i := decimals.RoundInt(555, -3) // i = 1000
Round a float to the given number of decimal places using a positive value for precision, or to the nearest power of ten using a negative value for precision.
f := decimals.RoundFloat(5.5555, 3) // f = 5.556
f := decimals.RoundFloat(5.5555, 2) // f = 5.56
f := decimals.RoundFloat(5.5555, 1) // f = 5.6
f := decimals.RoundFloat(5.5555, 0) // f = 6
f := decimals.RoundFloat(5.5555, -1) // f = 10
Formatting
Convert integers and floats to formatted strings with the given decimal precision, using a comma separator for thousands.
decimals.FormatInt(x int64, precision int) string
decimals.FormatFloat(x float64, precision int) string
Format an integer rounded to the nearest power of ten using a negative value for precision.
i := decimals.FormatInt(5555555, 0) // i = "5,555,555"
i := decimals.FormatInt(5555555, -1) // i = "5,555,560"
i := decimals.FormatInt(5555555, -2) // i = "5,555,600"
i := decimals.FormatInt(5555555, -3) // i = "5,556,000"
Format a float rounded to the given number of decimal places using a positive value for precision, or to the nearest power of ten using a negative value for precision.
f := decimals.FormatFloat(5555.555, 2) // f = "5,555.56"
f := decimals.FormatFloat(5555.555, 1) // f = "5,555.6"
f := decimals.FormatFloat(5555.555, 0) // f = "5,556"
f := decimals.FormatFloat(5555.555, -1) // f = "5,560"
f := decimals.FormatFloat(5555.555, -2) // f = "5,600"
Documentation
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Overview ¶
Package decimals is a small library of functions for rounding and formatting base ten numbers. These are functions that are either missing from the standard libraries or are more convenient for presenting numbers in a human-readable format.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func FormatFloat ¶
FormatFloat converts a float64 to a formatted string. The float is rounded to the given precision and formatted using a comma separator for thousands.
func FormatInt ¶
FormatInt converts an int64 to a formatted string. The int is rounded to the given precision and formatted using a comma separator for thousands.
func FormatThousands ¶
FormatThousands converts an int64 into a string formatted using a comma separator for thousands.
func RoundFloat ¶
RoundFloat rounds a base ten float64 to the given decimal precision. Precision may be positive, representing the number of decimal places, or negative, representing the nearest power of ten to which the float should be rounded.
func RoundInt ¶
RoundInt rounds a base ten int64 to the given precision. Precision is a negative number that represents the nearest power of ten to which the integer should be rounded. It is expressed as a negative number to be consistent with the decimal precision arguments used in rounding floats. If the rounded number falls outside the minimum and maximum for int64 the minimum or maximum will be returned instead.
Types ¶
This section is empty.
Source Files