Constraints (#31)

4 files changed, 38 insertions, 0 deletions

diff --git a/src/geom/gen.rs b/src/geom/gen.rs
index 075b7377..57dc277d 100644
--- a/src/geom/gen.rs
+++ b/src/geom/gen.rs
@@ -23,6 +23,14 @@ impl<T> Gen<T> {
         Self { cross: value.clone(), main: value }
     }
 
+    /// Maps the individual fields with `f`.
+    pub fn map<F, U>(self, mut f: F) -> Gen<U>
+    where
+        F: FnMut(T) -> U,
+    {
+        Gen { cross: f(self.cross), main: f(self.main) }
+    }
+
     /// Convert to the specific representation.
     pub fn to_spec(self, main: SpecAxis) -> Spec<T> {
         match main {
diff --git a/src/geom/linear.rs b/src/geom/linear.rs
index c3216b21..38d19b13 100644
--- a/src/geom/linear.rs
+++ b/src/geom/linear.rs
@@ -40,6 +40,11 @@ impl Linear {
     pub fn is_zero(self) -> bool {
         self.rel.is_zero() && self.abs.is_zero()
     }
+
+    /// Whether there is a linear component.
+    pub fn is_relative(&self) -> bool {
+        !self.rel.is_zero()
+    }
 }
 
 impl Display for Linear {
diff --git a/src/geom/size.rs b/src/geom/size.rs
index 4b94d0ae..7967dbdc 100644
--- a/src/geom/size.rs
+++ b/src/geom/size.rs
@@ -50,6 +50,11 @@ impl Size {
         Point::new(self.width, self.height)
     }
 
+    /// Convert to a Spec.
+    pub fn to_spec(self) -> Spec<Length> {
+        Spec::new(self.width, self.height)
+    }
+
     /// Convert to the generic representation.
     pub fn to_gen(self, main: SpecAxis) -> Gen<Length> {
         match main {
diff --git a/src/geom/spec.rs b/src/geom/spec.rs
index d0da3bca..f8f62f9f 100644
--- a/src/geom/spec.rs
+++ b/src/geom/spec.rs
@@ -26,6 +26,17 @@ impl<T> Spec<T> {
         }
     }
 
+    /// Maps the individual fields with `f`.
+    pub fn map<F, U>(self, mut f: F) -> Spec<U>
+    where
+        F: FnMut(T) -> U,
+    {
+        Spec {
+            horizontal: f(self.horizontal),
+            vertical: f(self.vertical),
+        }
+    }
+
     /// Convert to the generic representation.
     pub fn to_gen(self, main: SpecAxis) -> Gen<T> {
         match main {
@@ -33,6 +44,15 @@ impl<T> Spec<T> {
             SpecAxis::Vertical => Gen::new(self.horizontal, self.vertical),
         }
     }
+
+    /// Compare to whether two instances are equal when compared field-by-field
+    /// with `f`.
+    pub fn eq_by<U, F>(&self, other: &Spec<U>, eq: F) -> bool
+    where
+        F: Fn(&T, &U) -> bool,
+    {
+        eq(&self.vertical, &other.vertical) && eq(&self.horizontal, &other.horizontal)
+    }
 }
 
 impl Spec<Length> {