Add angle data type 📐

src/geom/angle.rs

@@ -0,0 +1,172 @@
+use std::f64::consts::PI;
+
+use super::*;
+
+/// An angle.
+#[derive(Default, Copy, Clone, PartialEq, PartialOrd)]
+pub struct Angle {
+    /// The angle in raw units.
+    raw: f64,
+}
+
+impl Angle {
+    /// The zero angle.
+    pub const ZERO: Self = Self { raw: 0.0 };
+
+    /// Create an angle from a number of radians.
+    pub fn rad(rad: f64) -> Self {
+        Self::with_unit(rad, AngularUnit::Rad)
+    }
+
+    /// Create an angle from a number of degrees.
+    pub fn deg(deg: f64) -> Self {
+        Self::with_unit(deg, AngularUnit::Deg)
+    }
+
+    /// Create an angle from a number of raw units.
+    pub fn raw(raw: f64) -> Self {
+        Self { raw }
+    }
+
+    /// Convert this to a number of radians.
+    pub fn to_rad(self) -> f64 {
+        self.to_unit(AngularUnit::Rad)
+    }
+
+    /// Convert this to a number of degrees.
+    pub fn to_deg(self) -> f64 {
+        self.to_unit(AngularUnit::Deg)
+    }
+
+    /// Get the value of this angle in raw units.
+    pub fn to_raw(self) -> f64 {
+        self.raw
+    }
+
+    /// Create an angle from a value in a unit.
+    pub fn with_unit(val: f64, unit: AngularUnit) -> Self {
+        Self { raw: val * unit.raw_scale() }
+    }
+
+    /// Get the value of this length in unit.
+    pub fn to_unit(self, unit: AngularUnit) -> f64 {
+        self.raw / unit.raw_scale()
+    }
+}
+
+impl Display for Angle {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{}{}", self.to_deg(), AngularUnit::Deg)
+    }
+}
+
+impl Debug for Angle {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        Display::fmt(self, f)
+    }
+}
+
+impl Neg for Angle {
+    type Output = Self;
+
+    fn neg(self) -> Self {
+        Self { raw: -self.raw }
+    }
+}
+
+impl Add for Angle {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self {
+        Self { raw: self.raw + other.raw }
+    }
+}
+
+sub_impl!(Angle - Angle -> Angle);
+
+impl Mul<f64> for Angle {
+    type Output = Self;
+
+    fn mul(self, other: f64) -> Self {
+        Self { raw: self.raw * other }
+    }
+}
+
+impl Mul<Angle> for f64 {
+    type Output = Angle;
+
+    fn mul(self, other: Angle) -> Angle {
+        other * self
+    }
+}
+
+impl Div<f64> for Angle {
+    type Output = Self;
+
+    fn div(self, other: f64) -> Self {
+        Self { raw: self.raw / other }
+    }
+}
+
+impl Div for Angle {
+    type Output = f64;
+
+    fn div(self, other: Self) -> f64 {
+        self.raw / other.raw
+    }
+}
+
+assign_impl!(Angle += Angle);
+assign_impl!(Angle -= Angle);
+assign_impl!(Angle *= f64);
+assign_impl!(Angle /= f64);
+
+impl Sum for Angle {
+    fn sum<I: Iterator<Item = Angle>>(iter: I) -> Self {
+        iter.fold(Angle::ZERO, Add::add)
+    }
+}
+/// Different units of angular measurement.
+#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
+pub enum AngularUnit {
+    /// Radians.
+    Rad,
+    /// Degrees.
+    Deg,
+}
+
+impl AngularUnit {
+    /// How many raw units correspond to a value of `1.0` in this unit.
+    fn raw_scale(self) -> f64 {
+        match self {
+            Self::Rad => 1.0,
+            Self::Deg => PI / 180.0,
+        }
+    }
+}
+
+impl Display for AngularUnit {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.pad(match self {
+            Self::Rad => "rad",
+            Self::Deg => "deg",
+        })
+    }
+}
+
+impl Debug for AngularUnit {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        Display::fmt(self, f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_angle_unit_conversion() {
+        assert!((Angle::rad(2.0 * PI).to_deg() - 360.0) < 1e-4);
+        assert!((Angle::deg(45.0).to_rad() - 0.7854) < 1e-4);
+    }
+}

src/geom/length.rs

@@ -13,22 +13,22 @@ impl Length {
 
     /// Create a length from a number of points.
     pub fn pt(pt: f64) -> Self {
-        Self::with_unit(pt, Unit::Pt)
+        Self::with_unit(pt, LengthUnit::Pt)
     }
 
     /// Create a length from a number of millimeters.
     pub fn mm(mm: f64) -> Self {
-        Self::with_unit(mm, Unit::Mm)
+        Self::with_unit(mm, LengthUnit::Mm)
     }
 
     /// Create a length from a number of centimeters.
     pub fn cm(cm: f64) -> Self {
-        Self::with_unit(cm, Unit::Cm)
+        Self::with_unit(cm, LengthUnit::Cm)
     }
 
     /// Create a length from a number of inches.
     pub fn inches(inches: f64) -> Self {
-        Self::with_unit(inches, Unit::In)
+        Self::with_unit(inches, LengthUnit::In)
     }
 
     /// Create a length from a number of raw units.
@@ -38,22 +38,22 @@ impl Length {
 
     /// Convert this to a number of points.
     pub fn to_pt(self) -> f64 {
-        self.to_unit(Unit::Pt)
+        self.to_unit(LengthUnit::Pt)
     }
 
     /// Convert this to a number of millimeters.
     pub fn to_mm(self) -> f64 {
-        self.to_unit(Unit::Mm)
+        self.to_unit(LengthUnit::Mm)
     }
 
     /// Convert this to a number of centimeters.
     pub fn to_cm(self) -> f64 {
-        self.to_unit(Unit::Cm)
+        self.to_unit(LengthUnit::Cm)
     }
 
     /// Convert this to a number of inches.
     pub fn to_inches(self) -> f64 {
-        self.to_unit(Unit::In)
+        self.to_unit(LengthUnit::In)
     }
 
     /// Get the value of this length in raw units.
@@ -62,12 +62,12 @@ impl Length {
     }
 
     /// Create a length from a value in a unit.
-    pub fn with_unit(val: f64, unit: Unit) -> Self {
+    pub fn with_unit(val: f64, unit: LengthUnit) -> Self {
         Self { raw: val * unit.raw_scale() }
     }
 
     /// Get the value of this length in unit.
-    pub fn to_unit(self, unit: Unit) -> f64 {
+    pub fn to_unit(self, unit: LengthUnit) -> f64 {
         self.raw / unit.raw_scale()
     }
 
@@ -86,9 +86,9 @@ impl Display for Length {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         // Format small lengths as points and large ones as centimeters.
         let (val, unit) = if self.to_pt().abs() < 25.0 {
-            (self.to_pt(), Unit::Pt)
+            (self.to_pt(), LengthUnit::Pt)
         } else {
-            (self.to_cm(), Unit::Cm)
+            (self.to_cm(), LengthUnit::Cm)
         };
         write!(f, "{}{}", (val * 100.0).round() / 100.0, unit)
     }
@@ -161,9 +161,9 @@ impl Sum for Length {
     }
 }
 
-/// Different units of measurement.
+/// Different units of length measurement.
 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
-pub enum Unit {
+pub enum LengthUnit {
     /// Points.
     Pt,
     /// Millimeters.
@@ -174,30 +174,30 @@ pub enum Unit {
     In,
 }
 
-impl Unit {
+impl LengthUnit {
     /// How many raw units correspond to a value of `1.0` in this unit.
     fn raw_scale(self) -> f64 {
         match self {
-            Unit::Pt => 1.0,
+            LengthUnit::Pt => 1.0,
-            Unit::Mm => 2.83465,
+            LengthUnit::Mm => 2.83465,
-            Unit::Cm => 28.3465,
+            LengthUnit::Cm => 28.3465,
-            Unit::In => 72.0,
+            LengthUnit::In => 72.0,
         }
     }
 }
 
-impl Display for Unit {
+impl Display for LengthUnit {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         f.pad(match self {
-            Unit::Mm => "mm",
+            LengthUnit::Mm => "mm",
-            Unit::Pt => "pt",
+            LengthUnit::Pt => "pt",
-            Unit::Cm => "cm",
+            LengthUnit::Cm => "cm",
-            Unit::In => "in",
+            LengthUnit::In => "in",
         })
     }
 }
 
-impl Debug for Unit {
+impl Debug for LengthUnit {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         Display::fmt(self, f)
     }

src/geom/mod.rs

@@ -3,6 +3,7 @@
 #[macro_use]
 mod macros;
 mod align;
+mod angle;
 mod dir;
 mod gen;
 mod length;
@@ -14,6 +15,7 @@ mod size;
 mod spec;
 
 pub use align::*;
+pub use angle::*;
 pub use dir::*;
 pub use gen::*;
 pub use length::*;

src/parse/tests.rs

@@ -5,7 +5,7 @@ use std::fmt::Debug;
 use super::parse;
 use crate::color::RgbaColor;
 use crate::diag::{Diag, Level, Pass};
-use crate::geom::Unit;
+use crate::geom::LengthUnit;
 use crate::syntax::*;
 
 use BinOp::*;
@@ -549,7 +549,7 @@ fn test_parse_expressions() {
     t!(r#"{"x"+"y"}"# Block(Binary(Str("x"), Add, Str("y"))));
     t!("{1-2}"        Block(Binary(Int(1), Sub, Int(2))));
     t!("{a * b}"      Block(Binary(Id("a"), Mul, Id("b"))));
-    t!("{12pt/.4}"    Block(Binary(Length(12.0, Unit::Pt), Div, Float(0.4))));
+    t!("{12pt/.4}"    Block(Binary(Length(12.0, LengthUnit::Pt), Div, Float(0.4))));
 
     // Associativity.
     t!("{1+2+3}" Block(Binary(Binary(Int(1), Add, Int(2)), Add, Int(3))));
@@ -593,8 +593,8 @@ fn test_parse_values() {
     t!("{1.0e-4}" Block(Float(1e-4)));
     t!("{3.15}"   Block(Float(3.15)));
     t!("{50%}"    Block(Percent(50.0)));
-    t!("{4.5cm}"  Block(Length(4.5, Unit::Cm)));
+    t!("{4.5cm}"  Block(Length(4.5, LengthUnit::Cm)));
-    t!("{12e1pt}" Block(Length(12e1, Unit::Pt)));
+    t!("{12e1pt}" Block(Length(12e1, LengthUnit::Pt)));
 
     // Strings.
     t!(r#"{"hi"}"#                     Block(Str("hi")));

src/parse/tokens.rs

@@ -1,7 +1,7 @@
 use std::fmt::{self, Debug, Formatter};
 
 use super::{is_newline, Scanner};
-use crate::geom::Unit;
+use crate::geom::LengthUnit;
 use crate::syntax::*;
 
 use TokenMode::*;
@@ -349,7 +349,7 @@ fn parse_percent(string: &str) -> Option<f64> {
     string.strip_suffix('%').and_then(|prefix| prefix.parse::<f64>().ok())
 }
 
-fn parse_length(string: &str) -> Option<(f64, Unit)> {
+fn parse_length(string: &str) -> Option<(f64, LengthUnit)> {
     let len = string.len();
 
     // We need at least some number and the unit.
@@ -362,10 +362,10 @@ fn parse_length(string: &str) -> Option<(f64, Unit)> {
     let split = len - 2;
     let bytes = string.as_bytes();
     let unit = match &bytes[split ..] {
-        b"pt" => Unit::Pt,
+        b"pt" => LengthUnit::Pt,
-        b"mm" => Unit::Mm,
+        b"mm" => LengthUnit::Mm,
-        b"cm" => Unit::Cm,
+        b"cm" => LengthUnit::Cm,
-        b"in" => Unit::In,
+        b"in" => LengthUnit::In,
         _ => return None,
     };
 
@@ -378,9 +378,9 @@ mod tests {
     use super::*;
     use crate::parse::tests::check;
 
+    use LengthUnit::*;
     use Option::None;
     use Token::{Ident, *};
-    use Unit::*;
 
     fn Raw(text: &str, backticks: usize, terminated: bool) -> Token {
         Token::Raw(TokenRaw { text, backticks, terminated })
@@ -737,7 +737,12 @@ mod tests {
         }
 
         // Test lengths.
-        for &unit in &[Unit::Mm, Unit::Pt, Unit::Cm, Unit::In] {
+        for &unit in &[
+            LengthUnit::Mm,
+            LengthUnit::Pt,
+            LengthUnit::Cm,
+            LengthUnit::In,
+        ] {
             for (s, v) in nums.clone() {
                 t!(Header[" /"]: format!("{}{}", s, unit) => Length(v, unit));
             }

src/syntax/expr.rs

@@ -1,6 +1,6 @@
 use super::*;
 use crate::color::RgbaColor;
-use crate::geom::Unit;
+use crate::geom::LengthUnit;
 
 /// An expression.
 #[derive(Debug, Clone, PartialEq)]
@@ -16,7 +16,7 @@ pub enum Expr {
     /// A floating-point literal: `1.2`, `10e-4`.
     Float(f64),
     /// A length literal: `12pt`, `3cm`.
-    Length(f64, Unit),
+    Length(f64, LengthUnit),
     /// A percent literal: `50%`.
     ///
     /// _Note_: `50%` is stored as `50.0` here, but as `0.5` in the

src/syntax/token.rs

@@ -1,4 +1,4 @@
-use crate::geom::Unit;
+use crate::geom::LengthUnit;
 
 /// A minimal semantic entity of source code.
 #[derive(Debug, Copy, Clone, PartialEq)]
@@ -70,7 +70,7 @@ pub enum Token<'s> {
     /// A floating-point number: `1.2`, `10e-4`.
     Float(f64),
     /// A length: `12pt`, `3cm`.
-    Length(f64, Unit),
+    Length(f64, LengthUnit),
     /// A percentage: `50%`.
     ///
     /// _Note_: `50%` is stored as `50.0` here, as in the corresponding