Add a Spectrum type

Cargo.toml

@@ -22,7 +22,9 @@ strict = []
 
 [dependencies]
 num = "0.1"
+ordered-float = "0.5.0"
 approx = "0.1"
+error-chain = "0.10.0"
 
 [dependencies.phf]
 version = "0.7"

src/errors.rs

@@ -0,0 +1,12 @@
+//! Module containing the errors that can be
+//! produced by the library.
+
+error_chain!{
+    errors {
+        /// Error representing an intensity sample being less than zero.
+        SpectrumIntensityOutOfRange {
+            description("Spectrum intensity value is out of range.")
+            display("Spectrum intensity value must be >= 0.")
+        }
+    }
+}

src/lib.rs

@@ -43,10 +43,17 @@
 #![cfg_attr(feature = "strict", deny(missing_docs))]
 #![cfg_attr(feature = "strict", deny(warnings))]
 
+// `error_chain!` can recurse deeply
+#![recursion_limit = "1024"]
+
 #[cfg_attr(test, macro_use)]
 extern crate approx;
 
+#[macro_use]
+extern crate error_chain;
+
 extern crate num;
+extern crate ordered_float;
 
 #[cfg(feature = "phf")]
 extern crate phf;
@@ -71,6 +78,7 @@ pub use hsv::{Hsv, Hsva};
 pub use hsl::{Hsl, Hsla};
 pub use yxy::{Yxy, Yxya};
 pub use hwb::{Hwb, Hwba};
+pub use spectrum::Spectrum;
 
 pub use hues::{LabHue, RgbHue};
 pub use convert::{FromColor, IntoColor};
@@ -229,6 +237,7 @@ macro_rules! assert_ranges {
     );
 }
 
+pub mod errors;
 pub mod gradient;
 pub mod pixel;
 pub mod blend;
@@ -246,6 +255,7 @@ mod lch;
 mod hsv;
 mod hsl;
 mod hwb;
+mod spectrum;
 
 mod hues;