Show default values in documentation

Fixes #169
Fixes #1102

3 files changed, 9 insertions, 1 deletions

diff --git a/src/eval/cast.rs b/src/eval/cast.rs
index b85d6e76..7ef2f1d0 100644
--- a/src/eval/cast.rs
+++ b/src/eval/cast.rs
@@ -230,6 +230,12 @@ impl<T: Cast> Cast for Option<T> {
     }
 }
 
+impl<T: Into<Value>> From<Spanned<T>> for Value {
+    fn from(spanned: Spanned<T>) -> Self {
+        spanned.v.into()
+    }
+}
+
 impl<T: Into<Value>> From<Option<T>> for Value {
     fn from(v: Option<T>) -> Self {
         match v {
diff --git a/src/eval/func.rs b/src/eval/func.rs
index 75231fc9..a224c5b8 100644
--- a/src/eval/func.rs
+++ b/src/eval/func.rs
@@ -279,6 +279,8 @@ pub struct ParamInfo {
     pub docs: &'static str,
     /// Valid values for the parameter.
     pub cast: CastInfo,
+    /// Creates an instance of the parameter's default value.
+    pub default: Option<fn() -> Value>,
     /// Is the parameter positional?
     pub positional: bool,
     /// Is the parameter named?
diff --git a/src/eval/value.rs b/src/eval/value.rs
index bd612cce..36cda80b 100644
--- a/src/eval/value.rs
+++ b/src/eval/value.rs
@@ -54,7 +54,7 @@ pub enum Value {
     Styles(Styles),
     /// An array of values: `(1, "hi", 12cm)`.
     Array(Array),
-    /// A dictionary value: `(color: #f79143, pattern: dashed)`.
+    /// A dictionary value: `(a: 1, b: "hi")`.
     Dict(Dict),
     /// An executable function.
     Func(Func),