6ce3949c8a* add `isNamedTuple`; make $(1, 2) be (1, 2) instead of leaking implementation detail (Field0: 1, Field1: 2) fixes this: #8670 (comment) /cc @alehander42 @Vindaar @mratsim * Note: isNamedTuple is useful in other places, eg #10010 (comment) * move isNamedTuple to helpers.nim to avoid exposing new symbol to system.nim * remove workaround in tests/vm/tissues.nim failing test now that #10218 was makes it work
68 lines
1.9 KiB
Nim
68 lines
1.9 KiB
Nim
#
|
|
#
|
|
# Nim's Runtime Library
|
|
# (c) Copyright 2012 Nim Contributors
|
|
#
|
|
# See the file "copying.txt", included in this
|
|
# distribution, for details about the copyright.
|
|
#
|
|
|
|
## This module defines compile-time reflection procs for
|
|
## working with types
|
|
|
|
include "system/helpers" # for `isNamedTuple`
|
|
|
|
export system.`$`
|
|
export isNamedTuple
|
|
|
|
proc name*(t: typedesc): string {.magic: "TypeTrait".}
|
|
## Alias for system.`$`(t) since Nim v0.20.0.
|
|
|
|
proc arity*(t: typedesc): int {.magic: "TypeTrait".} =
|
|
## Returns the arity of the given type. This is the number of "type" components or
|
|
## the number of generic parameters a given type ``t`` has.
|
|
runnableExamples:
|
|
assert arity(seq[string]) == 1
|
|
assert arity(array[3, int]) == 2
|
|
assert arity((int, int, float, string)) == 4
|
|
|
|
proc genericHead*(t: typedesc): typedesc {.magic: "TypeTrait".}
|
|
## Accepts an instantiated generic type and returns its
|
|
## uninstantiated form.
|
|
##
|
|
## For example:
|
|
## seq[int].genericHead will be just seq
|
|
## seq[int].genericHead[float] will be seq[float]
|
|
##
|
|
## A compile-time error will be produced if the supplied type
|
|
## is not generic.
|
|
|
|
proc stripGenericParams*(t: typedesc): typedesc {.magic: "TypeTrait".}
|
|
## This trait is similar to `genericHead`, but instead of producing
|
|
## error for non-generic types, it will just return them unmodified.
|
|
|
|
proc supportsCopyMem*(t: typedesc): bool {.magic: "TypeTrait".}
|
|
## This trait returns true iff the type ``t`` is safe to use for
|
|
## `copyMem`:idx:. Other languages name a type like these `blob`:idx:.
|
|
|
|
|
|
when isMainModule:
|
|
static:
|
|
doAssert $type(42) == "int"
|
|
doAssert int.name == "int"
|
|
|
|
const a1 = name(int)
|
|
const a2 = $(int)
|
|
const a3 = $int
|
|
doAssert a1 == "int"
|
|
doAssert a2 == "int"
|
|
doAssert a3 == "int"
|
|
|
|
proc fun[T: typedesc](t: T) =
|
|
const a1 = name(t)
|
|
const a2 = $(t)
|
|
const a3 = $t
|
|
doAssert a1 == "int"
|
|
doAssert a2 == "int"
|
|
doAssert a3 == "int"
|
|
fun(int)
|