rust-css add colors & test cases

[recrack]

No description provided.

[recrack]

r? @metajack

[metajack]

The idea is good, but I think this needs macro-izing.

something like:

define_color!(aliceblue, 240, 248, 255);

which would expand to:

static ALICEBLUE: Color = Color { red: 240, green: 248, blue: 255, alpha: 1.0 };

This also solves the problem of them being functions. I think this was due to an old compiler bug.

I'd delete all the color tests, as they are of dubious value. They would just check that the constants you created have the values you specify, but we already specify them once so it seems silly to have those numbers twice.

For the big match statement, you'll probably want to macro that too, with something like:

parse_static_color!(color, aliceblue, antiquewhite, ...);

which would expand to:

match color {
  "aliceblue" => ALICEBLUE,
  "antiquewhite" => ANTIQUEWHITE,
  ...
  _ => fail_unrecognized(color)
}

and used like:

let col = parse_static_color!(color, ...);

Or have the macro generate a function wrapping the match, etc.

[recrack]

#[macro_escape];
macro_rules! define_color(
    ($name:ident, $r:expr, $g:expr, $b:expr) => (
        {
            static $name: Color = Color { red: $r as u8, green: $g as u8, blue: $b as u8, alpha: 1.0 };
        }
    );
)

pub struct Color {
    red: u8,
    green: u8,
    blue: u8,
    alpha: f64,
}

fn main() {
    define_color!(black, 0, 255, 0);
}

@metajack Do have any idea? How to make indent string 'lowercase to uppercase' ?

 rustcn --pretty expanded macro.rs
#[macro_escape];
priv use std::prelude::*;
priv extern mod std;

mod __std_macros {
    #[macro_escape];
    #[doc(hidden)];
    priv use std::prelude::*;
    #[cfg(not(debug))]
    #[macro_escape]
    mod debug_macro {
        priv use std::prelude::*;
    }
}
pub struct Color {
    red: u8,
    green: u8,
    blue: u8,
    alpha: f64,
}
fn main() {
    {
        static black: Color =
            Color{red: 0 as u8, green: 255 as u8, blue: 0 as u8, alpha: 1.0,};
    };
}

[metajack]

@recrack I suggested a workaround in rust#8210. What did you think?

[recrack]

@metajack After i try your suggestion, and i will tell you. I think, your suggestion is good to me. i will try it.

[recrack]

@metajack i was try to make color macro-izing. but this code is not pretty.
May i have you good example code?
I want to follow you opinion.

and i have one question.

Variable is lowercase. Is it ok?

define_color!(aliceblue, 240, 248, 255);

which would expand to:

static aliceblue: Color = Color { red: 240, green: 248, blue: 255, alpha: 1.0 };

[metajack]

Here's a working set of the two macros. Perhpas all the method calls in parse_static_color! can be avoided, but I didn't look to see what hte inveraints were on the input that's passed in.

use std::ascii::AsciiStr;

struct Color { red: u8, green: u8, blue: u8, alpha: f64 }

macro_rules! define_color(
    ($color:ident, $r:expr, $g:expr, $b:expr) => {
        static $color: Color = Color { red: $r as u8, green: $g as u8, blue: $b as u8, alpha: 1.0 };
    }
)

macro_rules! parse_static_color(
    ($name:expr, $($color:ident),+) => {
        {
            let name = $name.trim().to_owned().into_ascii().to_upper().into_str();
            let mut color = None;
            $(
                if (stringify!($color) == name) {
                    color = Some($color);
                }
            )+
            color
        }
    }
)

define_color!(ALICEBLUE, 240, 248, 255)

fn parse_color(name: ~str) -> Option<Color> {
    parse_static_color!(name, ALICEBLUE)
}

fn main() {
    let name = ~"aliceblue";
    let color = parse_color(name);
    printfln!("%?", color);
}

[recrack]

Awesome!! @metajack.
Thank you for your help :)
r?

[metajack]

You almost have it.

parse_static_color! can take multiple arguments. Maybe I shouldn't have been lazy in my example. The intent is that you call it like:

parse_static_color!(color, ALICEBLUE, ANTIQUEWHITE, ...) with each color listed. Then you can remove that huge block of code with the single macro invocation.