Generic built-in functions

[raviqqe]

Problems

• Using operators for all generic operations is not scalable and extensible.

Solution

• Introduce built-in generic functions.
• Not every built-in function needs to be generic.
  • e.g. error(x any) and source(e error)
• Built-in functions cannot be re-defined or shadowed.
  • Therefore, all their use can be recognized at the parsing stage.
• Built-in functions must be called directly.

Built-in functions

• size(m [T] | {K: V}) number
• go(f \() T) \() T
  • This replaces the go keyword.
• race(xs [[T]]) [T]
• debug(xs any) none
• error(source any) error
• source(e error) any
• delete(m {K: V}, k K) {K: V}
  • delete built-in function for map types #1627
  • This replaced the key removal syntax for maps.
    • e.g. delete(m, "foo") for {string: number ...m, "foo"}

Future work

• reverse(xs [T]) [T]
  • reverse built-in function #1345
• sort(xs [T], f \(T, T) boolean) [T]
  • sort bulit-in function #1592

After MVP

• transpose([T | error]) [T] | error
  • transpose([T | none]) [T] | none too?
• reduce(x T, ys [S], f \(T, S) T) T
• zip([T], [S], \(T, S) U) [U]
• regex(s string) Regex
  • Compile time syntax check
• join(ss [string], sep string) string
  • Or join(ss ...[string]) string?

Replacing constructs?

• map([T], \(T) S) S
  • map({K: V}, \(K, V) T) T
  • e.g. map(xs, \(x number) string { Number'String(x) })
• filter([T], \(T) boolean) [T]

References

• builtin package | Go