> For the complete documentation index, see [llms.txt](https://gauntletlang.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gauntletlang.gitbook.io/docs/advanced-features/tagged-unions.md).

# Tagged Unions

## Syntax

```fsharp
enum <TaggedUnionName> {
    case <case name>(<FieldName> : <FieldType>, ...) // case syntax
}
```

## Example

{% tabs %}
{% tab title="Gauntlet" %}

```fsharp
package main

import "fmt" as fmt
import "strconv" as strconv

enum Shapes {
    Circle(diameter: Int, color: String)
    Square(width: Int, height: Int, color: String)
    Triangle(base: Int, width: Int, height: Int, color: String)
}

fun main(): Unit {
    fmt.println("I only like red triangles. Let's see...")
    
    let myShape = Triangle(base: 10, width : 5, height : 20, color : "red")
    
    match myShape {
        case Triangle(base: let b, height: let height, color : "red") : {
            fmt.println("It's a red triangle with a height of " + strconv.itoa(height) + " and base length of " + strconv.itoa(b) + "!")
        }
        case Square(width : let width, color : "red") : {
            fmt.println("It's a red square with a width of " + strconv.itoa(width))
        }
        case Circle(diameter: let diameter, color : "red") : {
            fmt.println("It's a red circle with a diameter of " + strconv.itoa(diameter))
        }
    }
}
```

{% endtab %}

{% tab title="Transpiled" %}

```go
package main

import fmt "fmt"
import strconv "strconv"

type Case343818345 struct {
	diameter int
	color    string
}

type Case421059818 struct {
	width  int
	height int
	color  string
}

type Case499594069 struct {
	base   int
	width  int
	height int
	color  string
}

func main() {
	fmt.Println("I only like red triangles. Let's see...")
	myShape := map[int]any{499594069: Case499594069{base: 10, width: 5, height: 20, color: "red"}}
	if _, exists := myShape[499594069]; exists {

		if height, b := myShape[499594069].(Case499594069).height, myShape[499594069].(Case499594069).base; (func() bool {
			return (myShape[499594069].(Case499594069).base == (b)) && (myShape[499594069].(Case499594069).height == (height)) && (myShape[499594069].(Case499594069).color == ("red"))
		})() {
			fmt.Println("It's a red triangle with a height of " + strconv.Itoa(height) + " and base length of " + strconv.Itoa(b) + "!")
		}
	}
	if _, exists := myShape[421059818]; exists {

		if width := myShape[421059818].(Case421059818).width; (func() bool {
			return (myShape[421059818].(Case421059818).width == (width)) && (myShape[421059818].(Case421059818).color == ("red"))
		})() {
			fmt.Println("It's a red square with a width of " + strconv.Itoa(width))
		}
	}
	if _, exists := myShape[343818345]; exists {

		if diameter := myShape[343818345].(Case343818345).diameter; (func() bool {
			return (myShape[343818345].(Case343818345).diameter == (diameter)) && (myShape[343818345].(Case343818345).color == ("red"))
		})() {
			fmt.Println("It's a red circle with a diameter of " + strconv.Itoa(diameter))
		}
	}
	// Eliminates any 'unused variable' errors
	_ = myShape

}

```

{% endtab %}

{% tab title="Output" %}

```
I only like red shapes. Let's see if this shape is red...
It's a red triangle with a height of 20 and base length of 10
```

{% endtab %}
{% endtabs %}


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