util

Documentation

Index

• Constants
• func DePunify(domain string) (string, error)
• func Decr[N Number](n N) N
• func Div[N Number](n1, n2 N) N
• func DoOnce(fn func()) func()
• func EmptyPageableResponse() *apimodel.PageableResponse
• func EqualPtrs[T comparable](t1, t2 *T) bool
• func ExtractNamestringParts(namestring string) (username, host string, err error)
• func ExtractWebfingerParts(subject string) (string, string, error)
• func FormatISO8601(t time.Time) string
• func FormatISO8601Date(t time.Time) string
• func FromSet[T comparable](in Set[T]) []T
• func IsNil(i interface{}) bool
• func KeyBy[S any, T comparable](in []S, key func(S) T) map[T]S
• func Must(fn func())
• func PackagePageableResponse(params PageableResponseParams) (*apimodel.PageableResponse, gtserror.WithCode)
• func ParseISO8601(in string) (time.Time, error)
• func Ptr[T any](t T) *T
• func PtrIf[T comparable](t T) *T
• func PtrOrValue[T any](t *T, value T) T
• func PtrOrZero[T any](t *T) T
• func Punify(domain string) (string, error)
• func PunifySafely(domain string) (string, error)
• func PunifyURI(in *url.URL) (*url.URL, error)
• func PunifyURIToStr(in *url.URL) (string, error)
• func URIMatches(expect *url.URL, uris ...*url.URL) (ok bool, err error)
• type Number
• type PageableResponseParams
• type Set
  • func ToSet[T comparable](in []T) Set[T]
  • func ToSetFunc[S any, T comparable](in []S, key func(S) T) Set[T]
  • func (s Set[T]) Has(v T) bool
  • func (s Set[T]) In(vs []T) []T
  • func (s Set[T]) NotIn(vs []T) []T

Constants

const ISO8601 = "2006-01-02T15:04:05.000Z"

ISO8601 is a formatter for serializing times that forces ISO8601 behavior.

const ISO8601Date = "2006-01-02"

Functions

func DePunify

func DePunify(domain string) (string, error)

DePunify converts any punycode-encoded unicode characters in domain name back to their origin unicode. Please note that this performs minimal validation of domain name.

func Decr

func Decr[N Number](n N) N

Decr performs a safe decrement of n, clamping minimum value at zero.

func Div

func Div[N Number](n1, n2 N) N

Div performs a safe division of n1 and n2, checking for zero n2. In the case of zero n2, zero is returned.

func DoOnce

func DoOnce(fn func()) func()

DoOnce wraps a function to only perform it once.

func EmptyPageableResponse

func EmptyPageableResponse() *apimodel.PageableResponse

EmptyPageableResponse just returns an empty PageableResponse with no link header or items.

func EqualPtrs

func EqualPtrs[T comparable](t1, t2 *T) bool

EqualPtrs returns whether the values contained within two comparable ptr types are equal.

func ExtractNamestringParts

func ExtractNamestringParts(namestring string) (username, host string, err error)

ExtractNamestringParts extracts the username test_user and the domain example.org from a string like @test_user@example.org.

If nothing is matched, it will return an error.

func ExtractWebfingerParts

func ExtractWebfingerParts(subject string) (
	string,
	string,
	error,
)

ExtractWebfingerParts returns the username and domain from the "subject" part of a webfinger response: either an account namestring or an actor URI.

All AP implementations in the wild perform webfinger account resource queries with the "acct" scheme and without a leading "@"" on the username. This is also the format the "subject" in a webfinger response adheres to.

Despite this fact, we're permissive about a single leading @. This makes a query for "acct:user@domain.tld" and "acct:@user@domain.tld" equivalent.

We also permit a resource of "user@domain.tld" or "@user@domain.tld", without a scheme. In that case it gets interpreted as if it was using "acct:".

Will error if parsing fails, or if the extracted username or domain are empty.

func FormatISO8601

func FormatISO8601(t time.Time) string

FormatISO8601 converts the given time to UTC and then formats it using the ISO8601 const, which the Mastodon API is able to understand.

func FormatISO8601Date

func FormatISO8601Date(t time.Time) string

Mastodon returns UTC dates (without time) for last_status_at/LastStatusAt as a special case, but most of the time you want to use FormatISO8601 instead.

func FromSet

func FromSet[T comparable](in Set[T]) []T

FromSet extracts the values from set to slice.

func IsNil

func IsNil(i interface{}) bool

func KeyBy

func KeyBy[S any, T comparable](in []S, key func(S) T) map[T]S

KeyBy creates a map of T->S, keyed by value returned from key func.

func Must

func Must(fn func())

Must executes 'fn' repeatedly until it successfully returns without panic.

func PackagePageableResponse

func PackagePageableResponse(params PageableResponseParams) (*apimodel.PageableResponse, gtserror.WithCode)

PackagePageableResponse is a convenience function for returning a bunch of pageable items (notifications, statuses, etc), as well as a Link header to inform callers of where to find next/prev items.

func ParseISO8601

func ParseISO8601(in string) (time.Time, error)

ParseISO8601 parses the given time string according to the ISO8601 const.

func Ptr

func Ptr[T any](t T) *T

Ptr returns a pointer to the passed in type

func PtrIf

func PtrIf[T comparable](t T) *T

PtrIf returns ptr value only if 't' non-zero.

func PtrOrValue

func PtrOrValue[T any](t *T, value T) T

PtrOrValue returns either contained value of ptr, or 'value'.

func PtrOrZero

func PtrOrZero[T any](t *T) T

PtrOrZero returns either value of ptr, or zero.

func Punify

func Punify(domain string) (string, error)

Punify is a faster form of PunifySafely() without validation.

func PunifySafely

func PunifySafely(domain string) (string, error)

PunifySafely validates the provided domain name, and converts unicode chars to ASCII, i.e. punified form.

func PunifyURI

func PunifyURI(in *url.URL) (*url.URL, error)

PunifyURI returns a new copy of URI with the 'host' part converted to punycode with PunifySafely(). For simple comparisons prefer the faster URIMatches().

func PunifyURIToStr

func PunifyURIToStr(in *url.URL) (string, error)

PunifyURIToStr returns given URI serialized with the 'host' part converted to punycode with PunifySafely(). For simple comparisons prefer the faster URIMatches().

func URIMatches

func URIMatches(expect *url.URL, uris ...*url.URL) (ok bool, err error)

URIMatches returns true if the expected URI matches any of the given URIs, taking account of punycode.

Types

type Number

type Number interface {
	~int | ~int8 | ~int16 | ~int32 | ~int64 |
		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 |
		~uintptr | ~float32 | ~float64
}

type PageableResponseParams

type PageableResponseParams struct {
	Items            []interface{} // Sorted slice of items (statuses, notifications, etc)
	Path             string        // path to use for next/prev queries in the link header
	NextMaxIDKey     string        // key to use for the next max id query param in the link header, defaults to 'max_id'
	NextMaxIDValue   string        // value to use for next max id
	PrevMinIDKey     string        // key to use for the prev min id query param in the link header, defaults to 'min_id'
	PrevMinIDValue   string        // value to use for prev min id
	Limit            int           // limit number of entries to return
	ExtraQueryParams []string      // any extra query parameters to provide in the link header, should be in the format 'example=value'
}

PageableResponseParams models the parameters to pass to PackagePageableResponse.

The given items will be provided in the paged response.

The other values are all used to create the Link header so that callers know which endpoint to query next and previously in order to do paging.

type Set

type Set[T comparable] map[T]struct{}

Set represents a hashmap of only keys, useful for deduplication / key checking.

func ToSet

func ToSet[T comparable](in []T) Set[T]

ToSet creates a Set[T] from given values.

func ToSetFunc

func ToSetFunc[S any, T comparable](in []S, key func(S) T) Set[T]

ToSetFunc creates a Set[T] from input slice, keys provided by func.

func (Set[T]) Has

func (s Set[T]) Has(v T) bool

Has returns if value is in Set.

func (Set[T]) In

func (s Set[T]) In(vs []T) []T

In returns input slice filtered to only contain those in receiving set.

func (Set[T]) NotIn

func (s Set[T]) NotIn(vs []T) []T

NotIn is the functional inverse of In().