helper

Documentation

Overview

Package helper provides some helpful functions.

Index

• Constants
• Variables
• func Bytes(s string) []byte
• func DecodeJSONFromBytes(dst interface{}, b []byte) error
• func DecodeJSONFromString(dst interface{}, s string) error
• func EncodeJSON(w io.Writer, value interface{}) error
• func EncodeJSONBytes(value interface{}) (data []byte, err error)
• func EncodeJSONString(value interface{}) (data string, err error)
• func IsZero(value interface{}) bool
• func MakeSlice[S ~[]E, E any, I ~int | ~int64](len, cap, defaultCap I) S
• func MapKeys[M ~map[K]V, K comparable, V any](maps M) []K
• func MapKeysFunc[M ~map[K]V, T any, K comparable, V any](maps M, convert func(K) T) []T
• func MapValues[M ~map[K]V, K comparable, V any](maps M) []V
• func MapValuesFunc[M ~map[K]V, T any, K comparable, V any](maps M, convert func(V) T) []T
• func MergeSlice[S ~[]E, E any](ss ...S) S
• func Must(err error)
• func MustV[T any](value T, err error) T
• func Random(buf []byte, charset string)
• func RandomString(n int, charset string) string
• func RemoveLineComments(data, comments []byte) []byte
• func String(b []byte) string
• func TimeAdd(t time.Time, years, months, days, hours, minutes, seconds int) time.Time
• func ToBoolMap[S ~[]T, T comparable](s S) map[T]bool
• func ToBoolMapFunc[S ~[]T, K comparable, T any](s S, convert func(T) K) map[K]bool
• func ToMap[S ~[]E, K comparable, V, E any](s S, convert func(E) (K, V)) map[K]V
• func ToMapWithIndex[S ~[]E, K comparable, V, E any](s S, convert func(int, E) (K, V)) map[K]V
• func ToSetMap[S ~[]T, T comparable](s S) map[T]struct{}
• func ToSetMapFunc[S ~[]T, K comparable, T any](s S, convert func(T) K) map[K]struct{}

Examples

• MapKeysFunc
• MapValuesFunc
• RemoveLineComments
• TimeAdd
• ToBoolMap
• ToBoolMapFunc
• ToSetMap
• ToSetMapFunc

Constants

const (
	Day  = time.Hour * 24
	Week = Day * 7
)

Some common durations.

Variables

var (
	CommentHash    = []byte("#")
	CommentSlashes = []byte("//")
)

Pre-define some comment characters.

var (
	NumCharset      = "0123456789"
	HexCharset      = NumCharset + "abcdefABCDEF"
	HexLowerCharset = NumCharset + "abcdef"
	HexUpperCharset = NumCharset + "ABCDEF"

	AlphaLowerCharset = "abcdefghijklmnopqrstuvwxyz"
	AlphaUpperCharset = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	AlphaCharset      = AlphaLowerCharset + AlphaUpperCharset

	AlphaNumLowerCharset = NumCharset + AlphaLowerCharset
	AlphaNumUpperCharset = NumCharset + AlphaUpperCharset
	AlphaNumCharset      = NumCharset + AlphaCharset

	DefaultCharset = AlphaNumLowerCharset
)

Pre-define some charsets to generate the random string.

var IntN = rand.Intn

IntN is the alias of the function "math/rand.Intn" or "math/rand/v2.IntN".

Functions

func Bytes

func Bytes(s string) []byte

Bytes converts the value s from string to []byte.

NOTICE: s must not be modified.

func DecodeJSONFromBytes

func DecodeJSONFromBytes(dst interface{}, b []byte) error

DecodeJSONFromBytes decodes the json raw bytes s into dst.

DEPRECATED!!!

func DecodeJSONFromString

func DecodeJSONFromString(dst interface{}, s string) error

DecodeJSONFromString decodes the json raw string s into dst.

DEPRECATED!!!

func EncodeJSON

func EncodeJSON(w io.Writer, value interface{}) error

EncodeJSON encodes the value by json into w.

NOTICE: it does not escape the problematic HTML characters.

func EncodeJSONBytes

func EncodeJSONBytes(value interface{}) (data []byte, err error)

EncodeJSONBytes encodes the value by json to bytes.

NOTICE: it does not escape the problematic HTML characters.

DEPRECATED!!!

func EncodeJSONString

func EncodeJSONString(value interface{}) (data string, err error)

EncodeJSONString encodes the value by json to string.

NOTICE: it does not escape the problematic HTML characters.

DEPRECATED!!!

func IsZero

func IsZero(value interface{}) bool

IsZero reports whether the value is ZERO.

If the value has implemented the interface{ IsZero() bool }, it will be called.

func MakeSlice

func MakeSlice[S ~[]E, E any, I ~int | ~int64](len, cap, defaultCap I) S

MakeSlice returns a new slice.

If both cap and defaultCap are equal to 0, it is equal to make(S, len). If cap is equal to 0, use defaultCap as cap instead, which is equal to make(S, len, defaultCap).

DEPRECATED!!!

func MapKeys

func MapKeys[M ~map[K]V, K comparable, V any](maps M) []K

MapKeys returns all the keys of the map.

DEPRECATED!!!

func MapKeysFunc

func MapKeysFunc[M ~map[K]V, T any, K comparable, V any](maps M, convert func(K) T) []T

MapKeysFunc returns all the keys of the map by the conversion function.

DEPRECATED!!!

Example

type Key struct {
	K string
	V int32
}
maps := map[Key]bool{
	{K: "a", V: 1}: true,
	{K: "b", V: 2}: true,
	{K: "c", V: 3}: true,
}

keys := MapKeysFunc(maps, func(k Key) string { return k.K })
slices.Sort(keys)
fmt.Println(keys)

Output:

[a b c]

func MapValues

func MapValues[M ~map[K]V, K comparable, V any](maps M) []V

MapValues returns all the values of the map.

DEPRECATED!!!

func MapValuesFunc

func MapValuesFunc[M ~map[K]V, T any, K comparable, V any](maps M, convert func(V) T) []T

MapValues returns all the values of the map by the conversion function.

DEPRECATED!!!

Example

type Value struct {
	V int
}
maps := map[string]Value{
	"a": {V: 1},
	"b": {V: 2},
	"c": {V: 3},
}

values := MapValuesFunc(maps, func(v Value) int { return v.V })
slices.Sort(values)
fmt.Println(values)

Output:

[1 2 3]

func MergeSlice

func MergeSlice[S ~[]E, E any](ss ...S) S

MergeSlice merges a set of slices in turn to one slice.

If no arguments, return nil. If all the arguments are empty, return a empty slice with cap==0.

DEPRECATED!!!

func Must

func Must(err error)

Must panics if err is not nil

func MustV

func MustV[T any](value T, err error) T

MustV returns value if err is nil. Or, panic with err instead.

DEPRECATED!!!

func Random

func Random(buf []byte, charset string)

Random generates a random string with the length from the given charsets into buf.

func RandomString

func RandomString(n int, charset string) string

RandomString generates a random string with the length from the given charsets.

func RemoveLineComments

func RemoveLineComments(data, comments []byte) []byte

RemoveLineComments is a simple function to remove the whole line comment that the first non-white character starts with comments, and the similar line tail comment.

Example

var slashOrig = []byte(`
// line comment 1
1
    /// line comment 2
2   ///// line tail comment 3
3
    4
	"//": "abc"
	"abc"  // the trailling comment containing "
5
`)

var hashOrig = []byte(`
# line comment 1
1
	## line comment 2
2   #### line tail comment 3
3
    4
	"#": "abc"
	"abc"  # the trailling comment containing "
5
`)

fmt.Println("Hash Result:")
fmt.Println(string(RemoveLineComments(hashOrig, CommentHash)))

fmt.Println("Slash Result:")
fmt.Println(string(RemoveLineComments(slashOrig, CommentSlashes)))

Output:

Hash Result:
1
2
3
    4
	"#": "abc"
	"abc"
5

Slash Result:
1
2
3
    4
	"//": "abc"
	"abc"
5

func String

func String(b []byte) string

String converts the value b from []byte to string.

NOTICE: b must not be modified.

func TimeAdd

func TimeAdd(t time.Time, years, months, days, hours, minutes, seconds int) time.Time

TimeAdd adds a duration to t and returns a new time.Time.

Example

t1 := time.Date(1, 2, 3, 4, 5, 6, 0, time.UTC)
t2 := TimeAdd(t1, 6, 5, 4, 3, 2, 1)

fmt.Printf("Year: %d\n", t2.Year())
fmt.Printf("Month: %d\n", t2.Month())
fmt.Printf("Day: %d\n", t2.Day())
fmt.Printf("Hour: %d\n", t2.Hour())
fmt.Printf("Minute: %d\n", t2.Minute())
fmt.Printf("Second: %d\n", t2.Second())

Output:

Year: 7
Month: 7
Day: 7
Hour: 7
Minute: 7
Second: 7

func ToBoolMap

func ToBoolMap[S ~[]T, T comparable](s S) map[T]bool

ToBoolMap converts a slice s to a bool map.

DEPRECATED!!!

Example

boolmap := ToBoolMap([]string{"a", "b", "c"})
fmt.Println(boolmap)

Output:

map[a:true b:true c:true]

func ToBoolMapFunc

func ToBoolMapFunc[S ~[]T, K comparable, T any](s S, convert func(T) K) map[K]bool

ToBoolMapFunc converts a slice s to a bool map by a conversion function.

DEPRECATED!!!

Example

type S struct {
	K string
	V int32
}

values := []S{{K: "a", V: 1}, {K: "b", V: 2}, {K: "c", V: 3}}
setmap := ToBoolMapFunc(values, func(s S) string { return s.K })
fmt.Println(setmap)

Output:

map[a:true b:true c:true]

func ToMap

func ToMap[S ~[]E, K comparable, V, E any](s S, convert func(E) (K, V)) map[K]V

DEPRECATED!!!

func ToMapWithIndex

func ToMapWithIndex[S ~[]E, K comparable, V, E any](s S, convert func(int, E) (K, V)) map[K]V

DEPRECATED!!!

func ToSetMap

func ToSetMap[S ~[]T, T comparable](s S) map[T]struct{}

ToSetMap converts a slice s to a set map.

DEPRECATED!!!

Example

setmap := ToSetMap([]string{"a", "b", "c"})
fmt.Println(setmap)

Output:

map[a:{} b:{} c:{}]

func ToSetMapFunc

func ToSetMapFunc[S ~[]T, K comparable, T any](s S, convert func(T) K) map[K]struct{}

ToSetMapFunc converts a slice s to a set map by a conversion function.

DEPRECATED!!!

Example

type S struct {
	K string
	V int32
}

values := []S{{K: "a", V: 1}, {K: "b", V: 2}, {K: "c", V: 3}}
setmap := ToSetMapFunc(values, func(s S) string { return s.K })
fmt.Println(setmap)

Output:

map[a:{} b:{} c:{}]