Flix (programming language): Difference between revisions

Revision as of 18:11, 22 June 2024

Revision as of 08:52, 26 September 2024

Line 48:

<syntaxhighlight lang="flx">

def main(): Unit &\ ImpureIO =

Console.printLine("Hello World!")

</syntaxhighlight>

The type and effect signature of the <code>main</code> function specifies that it has no parameters, returns a value of type <code>Unit</code>, and that the function has the IO effect, i.e. is impure. The <code>main</code> function is impure because it invokes <code>printLine</code> which is impure.

=== Algebraic data types and pattern matching ===

Line 60:

<syntaxhighlight lang="flx">

enum Shape {

case Circle(IntInt32), // has circle radius

case Square(IntInt32), // has side length

case Rectangle(IntInt32, IntInt32) // has height and width

}

</syntaxhighlight>

Line 71:

<syntaxhighlight lang="flx">

def area(s: Shape): IntInt32 = match s {

case Circle(r) => 3 * (r * r)

case Square(w) => w * w

Line 83:

<syntaxhighlight lang="flx">

def twice(f: IntInt32 -> IntInt32): IntInt32 -> IntInt32 = x -> f(f(x))

</syntaxhighlight>

Line 114:

<syntaxhighlight lang="flx">

def point2d(): {x: IntInt32, y: IntInt32} = {x = 1, y = 2}

</syntaxhighlight>

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<syntaxhighlight lang="flx">

def sum(r: {x: IntInt32, y: IntInt32 | rest}): Int = r.x + r.y

</syntaxhighlight>