Version: Next

Go-style built-ins (retired)

G# 0.4 shipped the Go-style built-in functions len, cap, append, and delete behind a per-file import Gsharp.Extensions.Go. ADR-0174 (D13) retired them, together with the import gate and the Gsharp.Extensions.Go namespace itself: every receiver already carries the member, so a free function that adds no syntax of its own only competed with it. A call to a retired name reports GS0566, whose message names the replacement for that exact site (xs.Length, m.Count, m.Remove(k), …). The names are free for your own functions: a user-defined func len(...) is an ordinary call.

Replacements

Retired	Receiver	Write instead
`len(xs)`	array `[N]T`, slice `[]T`, string, rectangular array	`xs.Length` (rectangular arrays also have `.Rank` and `.GetLength(d)`)
`len(m)`	`map[K, V]`	`m.Count`
`len(ch)`	a channel you constructed (`Chan[T]`)	`ch.Length()`
`cap(xs)`	slice	removed — a slice is a fixed CLR array whose capacity is its length, `xs.Length`
`cap(ch)`	a channel you constructed	`ch.Capacity`
`append(xs, v)`	slice	keep a growable `List[T]` and call `.Add(v)`; a slice is a fixed CLR array
`delete(m, k)`	`map[K, V]`	`m.Remove(k)`
`close(ch)`	channel	`ch.Close()`
`make(chan T[, n])`	—	`chan[T]()` (rendezvous), `chan[T](n)`, `Chan.Unbounded[T]()`

import System
import System.Collections.Generic

var nums = []int32{10, 20, 30}
Console.WriteLine(nums.Length)        // 3

var grown = List[int32]()
grown.Add(40)
Console.WriteLine(grown.Count)        // 1

var counts = map[string,int32]{"a": 1, "b": 2}
counts.Remove("a")
Console.WriteLine(counts.Count)       // 1

Console.WriteLine("hello".Length)     // 5

Because []T is T[] and map[K, V] is Dictionary[K, V] (ADR-0158 type identity), no new API ships with this change; the members were always there.

Replacements​

See also​

Replacements

See also