Variant keyword arguments

Context

• Mojo Reference: Variant
• Mojo Manual: Variadic keyword arguments
• Mojo Version: 24.2.0

Demo: Dynamic CSS Property Handler

This demo showcases a flexible CSS property handler, utilizing a Variant type to accept both string literals and integers as CSS property values. The CSS function dynamically processes various CSS properties provided as keyword arguments. It distinguishes between integers and string literals, allowing for a versatile way to handle CSS properties like color, font_size, background-color, and padding, demonstrating the language’s capability for type-safe yet flexible argument handling.

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from utils.variant import Variant

alias CSS_T=Variant[StringLiteral,Int]

fn CSS(**kwargs: CSS_T) raises:
    for i in kwargs:
        var kw=i[]
        if kwargs[kw].isa[Int](): print(kw, kwargs[kw].take[Int]())
        if kwargs[kw].isa[StringLiteral](): print(kw, kwargs[kw].take[StringLiteral]())
def main():
    CSS(color="yellow",font_size=16,`background-color`="blue",padding=4)

Output:

color yellow

font_size 16

background-color blue

padding 4

Remarks

Special thanks to @rd4com from the Modular Discord community for sharing this very useful demo on Discord.