Properly parse floating point numbers and rgba()

Cargo.lock

@@ -73,6 +73,7 @@ dependencies = [
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-bigint 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-rational 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 

Cargo.toml

@@ -25,6 +25,7 @@ clap = { version = "2.33.0", optional = true }
 lazy_static = "1.4.0"
 num-rational = "0.2.3"
 num-bigint = "0.2.6"
+num-traits = "0.2.11"
 
 [features]
 default = ["commandline"]

src/builtin/color.rs

@@ -2,7 +2,6 @@ use std::collections::BTreeMap;
 use std::convert::TryInto;
 
 use num_bigint::BigInt;
-use num_rational::BigRational;
 
 use super::Builtin;
 use crate::color::Color;
@@ -17,7 +16,23 @@ pub(crate) fn register(f: &mut BTreeMap<String, Builtin>) {
             let red: u16 = arg!(args, 0, "red").clone().try_into().unwrap();
             let green: u16 = arg!(args, 1, "green").clone().try_into().unwrap();
             let blue: u16 = arg!(args, 2, "blue").clone().try_into().unwrap();
-            Some(Value::Color(Color::from_values(red, green, blue, 1)))
+            Some(Value::Color(Color::from_values(red, green, blue, Number::from(1))))
+        } else {
+            todo!("channels variable in `rgb`")
+        }
+    });
+    decl!(f "rgba", |args, _| {
+        let channels = args.get("channels").unwrap_or(&Value::Null);
+        if channels.is_null() {
+            let red: u16 = arg!(args, 0, "red").clone().try_into().unwrap();
+            let green: u16 = arg!(args, 1, "green").clone().try_into().unwrap();
+            let blue: u16 = arg!(args, 2, "blue").clone().try_into().unwrap();
+            let alpha = match arg!(args, 3, "alpha").clone().eval() {
+                Value::Dimension(n, Unit::None) => n,
+                Value::Dimension(n, Unit::Percent) => n / Number::from(100),
+                _ => todo!("expected either unitless or % number for alpha"),
+            };
+            Some(Value::Color(Color::from_values(red, green, blue, alpha)))
         } else {
             todo!("channels variable in `rgb`")
         }
@@ -42,14 +57,14 @@ pub(crate) fn register(f: &mut BTreeMap<String, Builtin>) {
     });
     decl!(f "opacity", |args, _| {
         match arg!(args, 0, "color") {
-            Value::Color(c) => Some(Value::Dimension(Number::new(BigRational::new(BigInt::from(c.alpha()), BigInt::from(255))), Unit::None)),
+            Value::Color(c) => Some(Value::Dimension(c.alpha() / Number::from(255), Unit::None)),
             Value::Dimension(num, unit) => Some(Value::Ident(format!("opacity({}{})", num , unit), QuoteKind::None)),
             _ => todo!("non-color given to builtin function `opacity()`")
         }
     });
     decl!(f "alpha", |args, _| {
         match arg!(args, 0, "color") {
-            Value::Color(c) => Some(Value::Dimension(Number::new(BigRational::new(BigInt::from(c.alpha()), BigInt::from(255))), Unit::None)),
+            Value::Color(c) => Some(Value::Dimension(c.alpha() / Number::from(255), Unit::None)),
             _ => todo!("non-color given to builtin function `alpha()`")
         }
     });

src/color/mod.rs

@@ -1,6 +1,7 @@
 use std::fmt::{self, Display};
 
 pub(crate) use name::ColorName;
+use crate::value::{Number, Value};
 
 mod name;
 
@@ -9,17 +10,17 @@ pub(crate) struct Color {
     red: u16,
     green: u16,
     blue: u16,
-    alpha: u16,
+    alpha: Number,
     repr: String,
 }
 
 impl Color {
-    pub const fn new(red: u16, green: u16, blue: u16, alpha: u16, repr: String) -> Self {
+    pub fn new(red: u16, green: u16, blue: u16, alpha: u16, repr: String) -> Self {
         Color {
             red,
             green,
             blue,
-            alpha,
+            alpha: alpha.into(),
             repr,
         }
     }
@@ -36,15 +37,15 @@ impl Color {
         self.green
     }
 
-    pub const fn alpha(&self) -> u16 {
+    pub fn alpha(&self) -> Number {
-        self.alpha
+        self.alpha.clone()
     }
 
-    pub fn from_values(red: u16, green: u16, blue: u16, alpha: u16) -> Self {
+    pub fn from_values(red: u16, green: u16, blue: u16, alpha: Number) -> Self {
-        let repr = if alpha >= 1 {
+        let repr = if alpha >= Number::from(1) {
             format!("#{:0>2x}{:0>2x}{:0>2x}", red, green, blue)
         } else {
-            format!("#{:0>2x}{:0>2x}{:0>2x}{:0>2x}", red, green, blue, alpha)
+            format!("rgba({}, {}, {}, {})", red, green, blue, alpha)
         };
         Color {
             red,

src/lexer.rs

@@ -38,10 +38,24 @@ impl<'a> Iterator for Lexer<'a> {
             'a'..='z' | 'A'..='Z' | '-' | '_' => self.lex_ident(),
             '@' => self.lex_at_rule(),
             '0'..='9' => self.lex_num(),
+            '.' => {
+                self.buf.next();
+                self.pos.next_char();
+                match self.buf.peek().unwrap() {
+                    '0'..='9' => match self.lex_num() {
+                        TokenKind::Number(n) => {
+                            let mut s = String::from("0.");
+                            s.push_str(&n);
+                            TokenKind::Number(s)
+                        }
+                        _ => unsafe { std::hint::unreachable_unchecked() }
+                    }
+                    _ => TokenKind::Symbol(Symbol::Period)
+                }
+            }
             '$' => self.lex_variable(),
             ':' => symbol!(self, Colon),
             ',' => symbol!(self, Comma),
-            '.' => symbol!(self, Period),
             ';' => symbol!(self, SemiColon),
             '(' => symbol!(self, OpenParen),
             ')' => symbol!(self, CloseParen),

src/value/number.rs

@@ -1,6 +1,6 @@
 use std::convert::From;
 use std::fmt::{self, Display, Write};
-use std::ops::{Add, Sub};
+use std::ops::{Add, Sub, Mul, Div};
 
 use num_bigint::BigInt;
 use num_rational::BigRational;
@@ -30,6 +30,14 @@ impl From<BigInt> for Number {
     }
 }
 
+impl From<u16> for Number {
+    fn from(b: u16) -> Self {
+        Number {
+            val: BigRational::from_integer(BigInt::from(b)),
+        }
+    }
+}
+
 impl Display for Number {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{}", self.val.to_integer())?;
@@ -72,3 +80,23 @@ impl Sub for Number {
         }
     }
 }
+
+impl Mul for Number {
+    type Output = Self;
+
+    fn mul(self, other: Self) -> Self {
+        Number {
+            val: self.val * other.val,
+        }
+    }
+}
+
+impl Div for Number {
+    type Output = Self;
+
+    fn div(self, other: Self) -> Self {
+        Number {
+            val: self.val / other.val,
+        }
+    }
+}

src/value/parse.rs

@@ -1,6 +1,10 @@
 use std::convert::TryFrom;
 use std::iter::{Iterator, Peekable};
 
+use num_rational::BigRational;
+use num_bigint::BigInt;
+use num_traits::pow;
+
 use crate::args::eat_call_args;
 use crate::builtin::GLOBAL_FUNCTIONS;
 use crate::color::Color;
@@ -163,8 +167,29 @@ impl Value {
                 } else {
                     Unit::None
                 };
+                let n = match val.parse::<BigRational>() {
+                    // the number is an integer!
+                    Ok(v) => v,
+                    // the number is floating point
+                    Err(_) => {
+                        let mut num = String::new();
+                        let mut chars = val.chars().into_iter();
+                        let mut num_dec = 0;
+                        while let Some(c) = chars.next() {
+                            if c == '.' {
+                                break;
+                            }
+                            num.push(c);
+                        }
+                        for c in chars {
+                            num_dec += 1;
+                            num.push(c);
+                        }
+                        BigRational::new(num.parse().unwrap(), pow(BigInt::from(10), num_dec))
+                    }
+                };
                 Some(Value::Dimension(
-                    Number::new(val.parse().expect("error parsing integer")),
+                    Number::new(n),
                     unit,
                 ))
             }

tests/color.rs

@@ -64,3 +64,18 @@ test!(
     opacity_function_number_unit,
     "a {\n  color: opacity(1px);\n}\n"
 );
+test!(
+    rgba_opacity_over_1,
+    "a {\n  color: rgba(1, 2, 3, 3);\n}\n",
+    "a {\n  color: #010203;\n}\n"
+);
+test!(
+    rgba_opacity_decimal,
+    "a {\n  color: rgba(1, 2, 3, .6);\n}\n",
+    "a {\n  color: rgba(1, 2, 3, 0.6);\n}\n"
+);
+test!(
+    rgba_opacity_percent,
+    "a {\n  color: rgba(1, 2, 3, 50%);\n}\n",
+    "a {\n  color: rgba(1, 2, 3, 0.5);\n}\n"
+);