From d77ea0783786e863804a1c51186d6811187215f7 Mon Sep 17 00:00:00 2001 From: metagn Date: Fri, 6 Sep 2024 12:18:20 +0300 Subject: [PATCH] expose `rangeBase` typetrait, fix enum conversion warning (#24056) refs #21682, refs #24038 The `rangeBase` typetrait added in #21682 which gives the base type of a range type is now added publicly to `typetraits`. Previously it was only privately used in `repr_v2` and in `enumutils` since #24052 (coincidentally I didn't see this until now). This is part of an effort to make range types easier to work with in generics, as mentioned in #24038. Its use combined with #24037 is also tested. The condition for the "enum to enum conversion" warning is now also restricted to conversions between different enum base types, i.e. conversion between an enum type and a range type of itself doesn't give a warning. I put this in this PR since the test gave the warning and so works as a regression test. --- changelog.md | 2 ++ compiler/semexprs.nim | 3 ++- compiler/semmagic.nim | 5 +++-- lib/pure/typetraits.nim | 34 ++++++++++++++++++++++++++++++++++ tests/metatype/ttypetraits.nim | 26 ++++++++++++++++++++++++++ tests/misc/tconv.nim | 7 +++++++ 6 files changed, 74 insertions(+), 3 deletions(-) diff --git a/changelog.md b/changelog.md index 6c06e2913a283..305409fa5807b 100644 --- a/changelog.md +++ b/changelog.md @@ -55,6 +55,8 @@ - Added `setLenUninit` to system, which doesn't initialize slots when enlarging a sequence. - Added `hasDefaultValue` to `std/typetraits` to check if a type has a valid default value. +- Added `rangeBase` to `std/typetraits` to obtain the base type of a range type or + convert a value with a range type to its base type. - Added Viewport API for the JavaScript targets in the `dom` module. - Added `toSinglyLinkedRing` and `toDoublyLinkedRing` to `std/lists` to convert from `openArray`s. - ORC: To be enabled via `nimOrcStats` there is a new API called `GC_orcStats` that can be used to query how many diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim index fd53c07ffbfae..39121a671adb1 100644 --- a/compiler/semexprs.nim +++ b/compiler/semexprs.nim @@ -279,7 +279,8 @@ proc checkConvertible(c: PContext, targetTyp: PType, src: PNode): TConvStatus = result = checkConversionBetweenObjects(d.skipTypes(abstractInst), s.skipTypes(abstractInst), pointers) elif (targetBaseTyp.kind in IntegralTypes) and (srcBaseTyp.kind in IntegralTypes): - if targetTyp.kind == tyEnum and srcBaseTyp.kind == tyEnum: + if targetTyp.kind == tyEnum and srcBaseTyp.kind == tyEnum and + not sameType(targetTyp, srcBaseTyp): message(c.config, src.info, warnSuspiciousEnumConv, "suspicious code: enum to enum conversion") # `elif` would be incorrect here if targetTyp.kind == tyBool: diff --git a/compiler/semmagic.nim b/compiler/semmagic.nim index 1e579a959678e..1d97f192653d3 100644 --- a/compiler/semmagic.nim +++ b/compiler/semmagic.nim @@ -226,8 +226,9 @@ proc evalTypeTrait(c: PContext; traitCall: PNode, operand: PType, context: PSym) of "rangeBase": # return the base type of a range type var arg = operand.skipTypes({tyGenericInst}) - assert arg.kind == tyRange - result = getTypeDescNode(c, arg.base, operand.owner, traitCall.info) + if arg.kind == tyRange: + arg = arg.base + result = getTypeDescNode(c, arg, operand.owner, traitCall.info) of "isCyclic": var operand = operand.skipTypes({tyGenericInst}) let isCyclic = canFormAcycle(c.graph, operand) diff --git a/lib/pure/typetraits.nim b/lib/pure/typetraits.nim index 7c58d1ddc389a..78af84fdd4968 100644 --- a/lib/pure/typetraits.nim +++ b/lib/pure/typetraits.nim @@ -130,6 +130,40 @@ template pointerBase*[T](_: typedesc[ptr T | ref T]): typedesc = assert (var s = "abc"; s[0].addr).typeof.pointerBase is char T +proc rangeBase*(T: typedesc[range]): typedesc {.magic: "TypeTrait".} = + ## Returns the base type for range types, or the type itself otherwise. + ## + ## **See also:** + ## * `rangeBase template <#rangeBase.t,T>`_ + runnableExamples: + type MyRange = range[0..5] + type MyEnum = enum a, b, c + type MyEnumRange = range[b..c] + doAssert rangeBase(MyRange) is int + doAssert rangeBase(MyEnumRange) is MyEnum + doAssert rangeBase(range['a'..'z']) is char + +template rangeBase*[T: range](a: T): untyped = + ## Overload of `rangeBase <#rangeBase,typedesc,static[bool]>`_ for values. + runnableExamples: + type MyRange = range[0..5] + type MyEnum = enum a, b, c + type MyEnumRange = range[b..c] + let x = MyRange(3) + doAssert rangeBase(x) is int + doAssert $typeof(rangeBase(x)) == "int" + doAssert rangeBase(x) == 3 + let y: set[MyEnumRange] = {c} + for e in y: + doAssert rangeBase(e) is MyEnum + doAssert $typeof(rangeBase(e)) == "MyEnum" + doAssert rangeBase(e) == c + let z: seq[range['a'..'z']] = @['c'] + doAssert rangeBase(z[0]) is char + doAssert $typeof(rangeBase(z[0])) == "char" + doAssert rangeBase(z[0]) == 'c' + rangeBase(typeof(T))(a) + proc distinctBase*(T: typedesc, recursive: static bool = true): typedesc {.magic: "TypeTrait".} = ## Returns the base type for distinct types, or the type itself otherwise. ## If `recursive` is false, only the immediate distinct base will be returned. diff --git a/tests/metatype/ttypetraits.nim b/tests/metatype/ttypetraits.nim index 6ef59bcfa2bb6..0523390a760c7 100644 --- a/tests/metatype/ttypetraits.nim +++ b/tests/metatype/ttypetraits.nim @@ -144,6 +144,32 @@ block distinctBase: doAssert($distinctBase(typeof(b2)) == "string") doAssert($distinctBase(typeof(c2)) == "int") +block: # rangeBase + {.push warningAsError[EnumConv]: on.} + proc foo[T: not range](x: T): string = + $T & "(" & $x & ")" + proc foo[T: range](x: T): string = + "ranged(" & $low(T) & ".." & $high(T) & " of " & $rangeBase(T) & ") " & foo(rangeBase(x)) + doAssert foo(123) == "int(123)" + type IntRange = range[0..3] + let x: IntRange = 2 + doAssert foo(x) == "ranged(0..3 of int) int(2)" + type E = enum a, b, c, d, e, f + type EnumRange = range[c..e] + let y: EnumRange = d + doAssert foo(y) == "ranged(c..e of E) E(d)" + let z: range['a'..'z'] = 'g' + doAssert foo(z) == "ranged(a..z of char) char(g)" + {.pop.} + + # works only with #24037: + var toChange: range[0..3] = 1 + proc bar[T: int and not range](y: var T) = + inc y + doAssert not compiles(bar(toChange)) + bar(rangeBase(toChange)) + doAssert toChange == 2 + block: # tupleLen doAssert not compiles(tupleLen(int)) diff --git a/tests/misc/tconv.nim b/tests/misc/tconv.nim index e4a99344a8822..90fae868b0d87 100644 --- a/tests/misc/tconv.nim +++ b/tests/misc/tconv.nim @@ -88,6 +88,13 @@ block: # https://github.com/nim-lang/RFCs/issues/294 reject: Goo(k2) reject: k2.Goo + type KooRange = range[k2..k2] + accept: KooRange(k2) + accept: k2.KooRange + let k2ranged: KooRange = k2 + accept: Koo(k2ranged) + accept: k2ranged.Koo + reject: # bug #18550 proc f(c: char): cstring =