Luma color

2 files changed, 43 insertions, 34 deletions

diff --git a/src/library/mod.rs b/src/library/mod.rs
index 27658189..9708475b 100644
--- a/src/library/mod.rs
+++ b/src/library/mod.rs
@@ -85,6 +85,7 @@ pub fn new() -> Scope {
     std.def_fn("odd", utility::odd);
     std.def_fn("mod", utility::mod_);
     std.def_fn("range", utility::range);
+    std.def_fn("luma", utility::luma);
     std.def_fn("rgb", utility::rgb);
     std.def_fn("cmyk", utility::cmyk);
     std.def_fn("repr", utility::repr);
diff --git a/src/library/utility/color.rs b/src/library/utility/color.rs
index 5857c4c7..7c6ed873 100644
--- a/src/library/utility/color.rs
+++ b/src/library/utility/color.rs
@@ -2,57 +2,65 @@ use std::str::FromStr;
 
 use crate::library::prelude::*;
 
+/// Create a grayscale color.
+pub fn luma(_: &mut Machine, args: &mut Args) -> TypResult<Value> {
+    let Component(luma) = args.expect("gray component")?;
+    Ok(Value::Color(LumaColor::new(luma).into()))
+}
+
 /// Create an RGB(A) color.
 pub fn rgb(_: &mut Machine, args: &mut Args) -> TypResult<Value> {
-    Ok(Value::from(
+    Ok(Value::Color(
         if let Some(string) = args.find::<Spanned<EcoString>>()? {
             match RgbaColor::from_str(&string.v) {
-                Ok(color) => color,
+                Ok(color) => color.into(),
                 Err(msg) => bail!(string.span, msg),
             }
         } else {
-            struct Component(u8);
-
-            castable! {
-                Component,
-                Expected: "integer or ratio",
-                Value::Int(v) => match v {
-                    0 ..= 255 => Self(v as u8),
-                    _ => Err("must be between 0 and 255")?,
-                },
-                Value::Ratio(v) => if (0.0 ..= 1.0).contains(&v.get()) {
-                    Self((v.get() * 255.0).round() as u8)
-                } else {
-                    Err("must be between 0% and 100%")?
-                },
-            }
-
             let Component(r) = args.expect("red component")?;
             let Component(g) = args.expect("green component")?;
             let Component(b) = args.expect("blue component")?;
             let Component(a) = args.eat()?.unwrap_or(Component(255));
-            RgbaColor::new(r, g, b, a)
+            RgbaColor::new(r, g, b, a).into()
         },
     ))
 }
 
 /// Create a CMYK color.
 pub fn cmyk(_: &mut Machine, args: &mut Args) -> TypResult<Value> {
-    struct Component(u8);
+    let RatioComponent(c) = args.expect("cyan component")?;
+    let RatioComponent(m) = args.expect("magenta component")?;
+    let RatioComponent(y) = args.expect("yellow component")?;
+    let RatioComponent(k) = args.expect("key component")?;
+    Ok(Value::Color(CmykColor::new(c, m, y, k).into()))
+}
 
-    castable! {
-        Component,
-        Expected: "ratio",
-        Value::Ratio(v) => if (0.0 ..= 1.0).contains(&v.get()) {
-            Self((v.get() * 255.0).round() as u8)
-        } else {
-            Err("must be between 0% and 100%")?
-        },
-    }
+/// An integer or ratio component.
+struct Component(u8);
 
-    let Component(c) = args.expect("cyan component")?;
-    let Component(m) = args.expect("magenta component")?;
-    let Component(y) = args.expect("yellow component")?;
-    let Component(k) = args.expect("key component")?;
-    Ok(Value::Color(CmykColor::new(c, m, y, k).into()))
+castable! {
+    Component,
+    Expected: "integer or ratio",
+    Value::Int(v) => match v {
+        0 ..= 255 => Self(v as u8),
+        _ => Err("must be between 0 and 255")?,
+    },
+    Value::Ratio(v) => if (0.0 ..= 1.0).contains(&v.get()) {
+        Self((v.get() * 255.0).round() as u8)
+    } else {
+        Err("must be between 0% and 100%")?
+    },
+}
+
+/// A component that must be a ratio.
+struct RatioComponent(u8);
+
+castable! {
+    RatioComponent,
+    Expected: "ratio",
+    Value::Ratio(v) => if (0.0 ..= 1.0).contains(&v.get()) {
+        Self((v.get() * 255.0).round() as u8)
+    } else {
+        Err("must be between 0% and 100%")?
+    },
 }