cast

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Published: Aug 6, 2024 License: MIT Imports: 8 Imported by: 11,462

README

cast

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Easy and safe casting from one type to another in Go

Don’t Panic! ... Cast

What is Cast?

Cast is a library to convert between different go types in a consistent and easy way.

Cast provides simple functions to easily convert a number to a string, an interface into a bool, etc. Cast does this intelligently when an obvious conversion is possible. It doesn’t make any attempts to guess what you meant, for example you can only convert a string to an int when it is a string representation of an int such as “8”. Cast was developed for use in Hugo, a website engine which uses YAML, TOML or JSON for meta data.

Why use Cast?

When working with dynamic data in Go you often need to cast or convert the data from one type into another. Cast goes beyond just using type assertion (though it uses that when possible) to provide a very straightforward and convenient library.

If you are working with interfaces to handle things like dynamic content you’ll need an easy way to convert an interface into a given type. This is the library for you.

If you are taking in data from YAML, TOML or JSON or other formats which lack full types, then Cast is the library for you.

Usage

Cast provides a handful of To_____ methods. These methods will always return the desired type. If input is provided that will not convert to that type, the 0 or nil value for that type will be returned.

Cast also provides identical methods To_____E. These return the same result as the To_____ methods, plus an additional error which tells you if it successfully converted. Using these methods you can tell the difference between when the input matched the zero value or when the conversion failed and the zero value was returned.

The following examples are merely a sample of what is available. Please review the code for a complete set.

Example ‘ToString’:
cast.ToString("mayonegg")         // "mayonegg"
cast.ToString(8)                  // "8"
cast.ToString(8.31)               // "8.31"
cast.ToString([]byte("one time")) // "one time"
cast.ToString(nil)                // ""

var foo interface{} = "one more time"
cast.ToString(foo)                // "one more time"
Example ‘ToInt’:
cast.ToInt(8)                  // 8
cast.ToInt(8.31)               // 8
cast.ToInt("8")                // 8
cast.ToInt(true)               // 1
cast.ToInt(false)              // 0

var eight interface{} = 8
cast.ToInt(eight)              // 8
cast.ToInt(nil)                // 0

Documentation

Overview

Package cast provides easy and safe casting in Go.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func StringToDate

func StringToDate(s string) (time.Time, error)

StringToDate attempts to parse a string into a time.Time type using a predefined list of formats. If no suitable format is found, an error is returned.

func StringToDateInDefaultLocation added in v1.4.0

func StringToDateInDefaultLocation(s string, location *time.Location) (time.Time, error)

StringToDateInDefaultLocation casts an empty interface to a time.Time, interpreting inputs without a timezone to be in the given location, or the local timezone if nil.

func ToBool

func ToBool(i interface{}) bool

ToBool casts an interface to a bool type.

func ToBoolE

func ToBoolE(i interface{}) (bool, error)

ToBoolE casts an interface to a bool type.

func ToBoolSlice

func ToBoolSlice(i interface{}) []bool

ToBoolSlice casts an interface to a []bool type.

func ToBoolSliceE

func ToBoolSliceE(i interface{}) ([]bool, error)

ToBoolSliceE casts an interface to a []bool type.

func ToDuration

func ToDuration(i interface{}) time.Duration

ToDuration casts an interface to a time.Duration type.

func ToDurationE

func ToDurationE(i interface{}) (d time.Duration, err error)

ToDurationE casts an interface to a time.Duration type.

func ToDurationSlice added in v1.1.0

func ToDurationSlice(i interface{}) []time.Duration

ToDurationSlice casts an interface to a []time.Duration type.

func ToDurationSliceE added in v1.1.0

func ToDurationSliceE(i interface{}) ([]time.Duration, error)

ToDurationSliceE casts an interface to a []time.Duration type.

func ToFloat32

func ToFloat32(i interface{}) float32

ToFloat32 casts an interface to a float32 type.

func ToFloat32E

func ToFloat32E(i interface{}) (float32, error)

ToFloat32E casts an interface to a float32 type.

func ToFloat64

func ToFloat64(i interface{}) float64

ToFloat64 casts an interface to a float64 type.

func ToFloat64E

func ToFloat64E(i interface{}) (float64, error)

ToFloat64E casts an interface to a float64 type.

func ToInt

func ToInt(i interface{}) int

ToInt casts an interface to an int type.

func ToInt16

func ToInt16(i interface{}) int16

ToInt16 casts an interface to an int16 type.

func ToInt16E

func ToInt16E(i interface{}) (int16, error)

ToInt16E casts an interface to an int16 type.

func ToInt32

func ToInt32(i interface{}) int32

ToInt32 casts an interface to an int32 type.

func ToInt32E

func ToInt32E(i interface{}) (int32, error)

ToInt32E casts an interface to an int32 type.

func ToInt64

func ToInt64(i interface{}) int64

ToInt64 casts an interface to an int64 type.

func ToInt64E

func ToInt64E(i interface{}) (int64, error)

ToInt64E casts an interface to an int64 type.

func ToInt8

func ToInt8(i interface{}) int8

ToInt8 casts an interface to an int8 type.

func ToInt8E

func ToInt8E(i interface{}) (int8, error)

ToInt8E casts an interface to an int8 type.

func ToIntE

func ToIntE(i interface{}) (int, error)

ToIntE casts an interface to an int type.

func ToIntSlice

func ToIntSlice(i interface{}) []int

ToIntSlice casts an interface to a []int type.

func ToIntSliceE

func ToIntSliceE(i interface{}) ([]int, error)

ToIntSliceE casts an interface to a []int type.

func ToSlice

func ToSlice(i interface{}) []interface{}

ToSlice casts an interface to a []interface{} type.

func ToSliceE

func ToSliceE(i interface{}) ([]interface{}, error)

ToSliceE casts an interface to a []interface{} type.

func ToString

func ToString(i interface{}) string

ToString casts an interface to a string type.

func ToStringE

func ToStringE(i interface{}) (string, error)

ToStringE casts an interface to a string type.

func ToStringMap

func ToStringMap(i interface{}) map[string]interface{}

ToStringMap casts an interface to a map[string]interface{} type.

func ToStringMapBool

func ToStringMapBool(i interface{}) map[string]bool

ToStringMapBool casts an interface to a map[string]bool type.

func ToStringMapBoolE

func ToStringMapBoolE(i interface{}) (map[string]bool, error)

ToStringMapBoolE casts an interface to a map[string]bool type.

func ToStringMapE

func ToStringMapE(i interface{}) (map[string]interface{}, error)

ToStringMapE casts an interface to a map[string]interface{} type.

func ToStringMapInt added in v1.3.0

func ToStringMapInt(i interface{}) map[string]int

ToStringMapInt casts an interface to a map[string]int type.

func ToStringMapInt64 added in v1.3.0

func ToStringMapInt64(i interface{}) map[string]int64

ToStringMapInt64 casts an interface to a map[string]int64 type.

func ToStringMapInt64E added in v1.3.0

func ToStringMapInt64E(i interface{}) (map[string]int64, error)

ToStringMapInt64E casts an interface to a map[string]int64{} type.

func ToStringMapIntE added in v1.3.0

func ToStringMapIntE(i interface{}) (map[string]int, error)

ToStringMapIntE casts an interface to a map[string]int{} type.

func ToStringMapString

func ToStringMapString(i interface{}) map[string]string

ToStringMapString casts an interface to a map[string]string type.

func ToStringMapStringE

func ToStringMapStringE(i interface{}) (map[string]string, error)

ToStringMapStringE casts an interface to a map[string]string type.

func ToStringMapStringSlice

func ToStringMapStringSlice(i interface{}) map[string][]string

ToStringMapStringSlice casts an interface to a map[string][]string type.

func ToStringMapStringSliceE

func ToStringMapStringSliceE(i interface{}) (map[string][]string, error)

ToStringMapStringSliceE casts an interface to a map[string][]string type.

func ToStringSlice

func ToStringSlice(i interface{}) []string

ToStringSlice casts an interface to a []string type.

func ToStringSliceE

func ToStringSliceE(i interface{}) ([]string, error)

ToStringSliceE casts an interface to a []string type.

func ToTime

func ToTime(i interface{}) time.Time

ToTime casts an interface to a time.Time type.

func ToTimeE

func ToTimeE(i interface{}) (tim time.Time, err error)

ToTimeE casts an interface to a time.Time type.

func ToTimeInDefaultLocation added in v1.4.0

func ToTimeInDefaultLocation(i interface{}, location *time.Location) time.Time

func ToTimeInDefaultLocationE added in v1.4.0

func ToTimeInDefaultLocationE(i interface{}, location *time.Location) (tim time.Time, err error)

ToTimeInDefaultLocationE casts an empty interface to time.Time, interpreting inputs without a timezone to be in the given location, or the local timezone if nil.

func ToUint

func ToUint(i interface{}) uint

ToUint casts an interface to a uint type.

func ToUint16

func ToUint16(i interface{}) uint16

ToUint16 casts an interface to a uint16 type.

func ToUint16E

func ToUint16E(i interface{}) (uint16, error)

ToUint16E casts an interface to a uint16 type.

func ToUint32

func ToUint32(i interface{}) uint32

ToUint32 casts an interface to a uint32 type.

func ToUint32E

func ToUint32E(i interface{}) (uint32, error)

ToUint32E casts an interface to a uint32 type.

func ToUint64

func ToUint64(i interface{}) uint64

ToUint64 casts an interface to a uint64 type.

func ToUint64E

func ToUint64E(i interface{}) (uint64, error)

ToUint64E casts an interface to a uint64 type.

func ToUint8

func ToUint8(i interface{}) uint8

ToUint8 casts an interface to a uint8 type.

func ToUint8E

func ToUint8E(i interface{}) (uint8, error)

ToUint8E casts an interface to a uint type.

func ToUintE

func ToUintE(i interface{}) (uint, error)

ToUintE casts an interface to a uint type.

Types

This section is empty.

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