taggedalgebraic 0.11.13
A "tagged union" implementation with transparent operator forwarding.
To use this package, run the following command in your project's root directory:
Manual usage
Put the following dependency into your project's dependences section:
TaggedAlgebraic
Implementation of a generic TaggedUnion
type along with a TaggedAlgebraic
type that forwards all methods and operators of the contained types using dynamic dispatch.
API Documentation:
Usage of TaggedUnion
import taggedalgebraic;
struct Foo {
string name;
void bar() {}
}
union Base {
int count;
int offset;
string str;
Foo foo;
}
alias TUnion = TaggedUnion!Base;
// Instantiate
TUnion taggedInt = TUnion.count(5);
TUnion taggedString = TUnion.str("Hello");
TUnion taggedFoo = TUnion.foo;
TUnion taggedAny = taggedInt;
taggedAny = taggedString;
taggedAny = taggedFoo;
// Default initializes to the first field
TUnion taggedDef;
assert(taggedDef.isCount);
assert(taggedDef.countValue == int.init);
// Check type: TUnion.Kind is an enum
assert(taggedInt.kind == TUnion.Kind.count);
assert(taggedString.kind == TUnion.Kind.str);
assert(taggedFoo.kind == TUnion.Kind.foo);
assert(taggedAny.kind == TUnion.Kind.foo);
// A shorter syntax is also available
assert(taggedInt.isCount);
assert(!taggedInt.isOffset);
assert(taggedString.isStr);
assert(taggedFoo.isFoo);
assert(taggedAny.isFoo);
// Set to a different type
taggedAny.setStr("bar");
assert(taggedAny.isStr);
assert(taggedAny.strValue == "bar");
// Modify contained value by reference
taggedAny.strValue = "baz";
assert(taggedAny.strValue == "baz");
// In addition to the getter, the contained value can be extracted using get!()
// or by casting
assert(taggedInt.value!(TUnion.Kind.count) == 5);
assert(taggedInt.value!int == 5);
assert(cast(byte)taggedInt == 5);
// Multiple kinds of the same type are supported
taggedAny.setOffset(5);
assert(taggedAny.isOffset);
assert(!taggedAny.isCount);
// Unique types can also be set directly
taggedAny = "foo";
assert(taggedAny.isStr);
taggedAny = TUnion(Foo.init);
assert(taggedAny.isFoo);
Usage of TaggedAlgebraic
import taggedalgebraic;
struct Foo {
string name;
void bar() {}
}
union Base {
int i;
string str;
Foo foo;
}
alias TAlgebraic = TaggedAlgebraic!Base;
// Instantiate
TAlgebraic taggedInt = 5;
TAlgebraic taggedString = "Hello";
TAlgebraic taggedFoo = Foo();
TAlgebraic taggedAny = taggedInt;
taggedAny = taggedString;
taggedAny = taggedFoo;
// Check type: TAlgebraic.Kind is an enum
assert(taggedInt.kind == TAlgebraic.Kind.i);
assert(taggedString.kind == TAlgebraic.Kind.str);
assert(taggedFoo.kind == TAlgebraic.Kind.foo);
assert(taggedAny.kind == TAlgebraic.Kind.foo);
// In most cases, can simply use as-is
auto num = 4 + taggedInt;
auto msg = taggedString ~ " World!";
taggedFoo.bar();
if (taggedAny.kind == TAlgebraic.Kind.foo) // Make sure to check type first!
taggedAny.bar();
//taggedString.bar(); // AssertError: Not a Foo!
// Convert back by casting
auto i = cast(int) taggedInt;
auto str = cast(string) taggedString;
auto foo = cast(Foo) taggedFoo;
if (taggedAny.kind == TAlgebraic.Kind.foo) // Make sure to check type first!
auto foo2 = cast(Foo) taggedAny;
//cast(Foo) taggedString; // AssertError!
// Kind is an enum, so final switch is supported:
final switch (taggedAny.kind) {
case TAlgebraic.Kind.i:
// It's "int i"
break;
case TAlgebraic.Kind.str:
// It's "string str"
break;
case TAlgebraic.Kind.foo:
// It's "Foo foo"
break;
}
Compiler support
The library is tested to work on the following compilers:
- DMD 2.076.1 up to 2.088.0
- LDC 1.6.0 up to 1.17.0
- Registered by Sönke Ludwig
- 0.11.13 released 4 years ago
- s-ludwig/taggedalgebraic
- BSL-1.0
- Copyright © 2015, Sönke Ludiwg
- Authors:
- Dependencies:
- none
- Versions:
-
0.11.23 2024-Apr-18 0.11.22 2021-May-20 0.11.21 2021-Mar-31 0.11.20 2021-Mar-16 0.11.19 2021-Jan-13 - Download Stats:
-
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497 downloads today
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2142 downloads this week
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11071 downloads this month
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1880069 downloads total
-
- Score:
- 4.3
- Short URL:
- taggedalgebraic.dub.pm