Golang Dynamic Type Cast

The cast package provides utilities for type casting and conversion in Go. It includes functions for converting values to various Go types, such as bool, int, uint, float, string, and their respective slices. Additionally, it offers a Caster interface for more structured type conversion.

Installation

To install the cast package, use the following command:

go get github.com/go-universal/cast

Then, import the package in your Go code:

import "github.com/go-universal/cast"

Functions

ToBool

Converts an interface to a bool.
Signature:

func ToBool(value interface{}) (bool, error)

Example:

result, err := cast.ToBool("true")
fmt.Println(result) // Output: true

ToBoolSlice

Converts an interface to a slice of bool.
Signature:

func ToBoolSlice(value interface{}) ([]bool, error)

Example:

result, err := cast.ToBoolSlice([]string{"true", "false"})
fmt.Println(result) // Output: [true false]

ToSigned

Converts an interface to a signed integer type (int, int8, int16, int32, int64).
Signature:

func ToSigned[T int | int8 | int16 | int32 | int64](value interface{}) (T, error)

Example:

result, err := cast.ToSigned[int]("123")
fmt.Println(result) // Output: 123

ToSignedSlice

Converts an interface to a slice of signed integers.
Signature:

func ToSignedSlice[T int | int8 | int16 | int32 | int64](value interface{}) ([]T, error)

Example:

result, err := cast.ToSignedSlice[int]([]string{"1", "2"})
fmt.Println(result) // Output: [1 2]

ToUnsigned

Converts an interface to an unsigned integer type (uint, uint8, uint16, uint32, uint64).
Signature:

func ToUnsigned[T uint | uint8 | uint16 | uint32 | uint64](value interface{}) (T, error)

Example:

result, err := cast.ToUnsigned[uint]("123")
fmt.Println(result) // Output: 123

ToUnsignedSlice

Converts an interface to a slice of unsigned integers.
Signature:

func ToUnsignedSlice[T uint | uint8 | uint16 | uint32 | uint64](value interface{}) ([]T, error)

Example:

result, err := cast.ToUnsignedSlice[uint]([]string{"1", "2"})
fmt.Println(result) // Output: [1 2]

ToFloat

Converts an interface to a float type (float32, float64).
Signature:

func ToFloat[T float32 | float64](value interface{}) (T, error)

Example:

result, err := cast.ToFloat[float64]("123.45")
fmt.Println(result) // Output: 123.45

ToFloatSlice

Converts an interface to a slice of floats.
Signature:

func ToFloatSlice[T float32 | float64](value interface{}) ([]T, error)

Example:

result, err := cast.ToFloatSlice[float64]([]string{"1.1", "2.2"})
fmt.Println(result) // Output: [1.1 2.2]

ToString

Converts an interface to a string.
Signature:

func ToString(value interface{}) (string, error)

Example:

result, err := cast.ToString(123)
fmt.Println(result) // Output: "123"

ToStringSlice

Converts an interface to a slice of string.
Signature:

func ToStringSlice(value interface{}) ([]string, error)

Example:

result, err := cast.ToStringSlice([]int{1, 2})
fmt.Println(result) // Output: ["1" "2"]

ToSlice

Converts an interface to a slice of interface{}.
Signature:

func ToSlice(value interface{}) ([]interface{}, error)

Example:

result, err := cast.ToSlice([]int{1, 2})
fmt.Println(result) // Output: [1 2]

Caster Interface

The Caster interface provides methods for type casting and conversion. It allows structured and reusable type conversions with fallback mechanisms.

Methods

• IsNil() bool: Checks if the value is nil.
• Interface() interface{}: Returns the value as an interface{}.
• Bool() (bool, error): Converts the value to a bool.
• BoolSafe(fallback bool) bool: Converts the value to a bool, returning a fallback value on error.
• BoolSlice() ([]bool, error): Converts the value to a slice of bool.
• BoolSliceSafe(fallback []bool) []bool: Converts the value to a slice of bool, returning a fallback value on error.
• Int() (int, error): Converts the value to an int.
• IntSafe(fallback int) int: Converts the value to an int, returning a fallback value on error.
• IntSlice() ([]int, error): Converts the value to a slice of int.
• IntSliceSafe(fallback []int) []int: Converts the value to a slice of int, returning a fallback value on error.
• Float64() (float64, error): Converts the value to a float64.
• Float64Safe(fallback float64) float64: Converts the value to a float64, returning a fallback value on error.
• String() (string, error): Converts the value to a string.
• StringSafe(fallback string) string: Converts the value to a string, returning a fallback value on error.

Example Usage

caster := cast.NewCaster("123")

// Convert to int
intValue, err := caster.Int()
fmt.Println(intValue) // Output: 123

// Convert to bool with fallback
boolValue := caster.BoolSafe(false)
fmt.Println(boolValue) // Output: true

// Convert to string slice
stringSlice, err := caster.StringSlice()
fmt.Println(stringSlice) // Output: ["1" "2" "3"]

Error Handling

The package provides utility functions to identify specific error types:

• IsNilError(err error) bool: Checks if the error is due to a nil value.
• IsCastError(err error) bool: Checks if the error is due to an invalid type conversion.
• IsOverflowError(err error) bool: Checks if the error is due to a value overflow.

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This documentation provides a comprehensive overview of the cast package and its capabilities. For more details, refer to the source code or examples provided in the repository.