remove View; allow rendering Result

dsl/src/dsl_provide.rs

@@ -16,19 +16,35 @@ use crate::*;
 
 /// Maps a sequencer of EDN tokens to parameters of supported types
 /// for a given context.
-pub trait Dsl<U>: Sized {
-    fn take <'state, 'source> (
-        &'state self,
-        _: &mut TokenIter<'source>
-    ) -> Perhaps<U> {
+pub trait Dsl<Value>: Sized {
+    fn take <'state, 'source> (&'state self, _: &mut TokenIter<'source>) -> Perhaps<Value> {
         unimplemented!()
     }
     fn take_or_fail <'state, 'source> (
         &'state self,
         token: &mut TokenIter<'source>,
         error: impl Into<Box<dyn std::error::Error>>
-    ) -> Usually<U> {
-        if let Some(value) = Dsl::<U>::take(self, token)? {
+    ) -> Usually<Value> {
+        if let Some(value) = Dsl::<Value>::take(self, token)? {
+            Ok(value)
+        } else {
+            Result::Err(error.into())
+        }
+    }
+}
+
+pub trait FromDsl<'state, State>: Sized {
+    fn take_from <'source: 'state> (state: &'state State, _token: &mut TokenIter<'source>)
+        -> Perhaps<Self>
+    {
+        unimplemented!()
+    }
+    fn take_from_or_fail <'source: 'state> (
+        state: &'state State,
+        token: &mut TokenIter<'source>,
+        error: impl Into<Box<dyn std::error::Error>>
+    ) -> Usually<Self> {
+        if let Some(value) = FromDsl::<State>::take_from(state, token)? {
             Ok(value)
         } else {
             Result::Err(error.into())
@@ -53,23 +69,3 @@ impl<'state, X, Y> Dsl<X> for Y where Y: FromDsl<'state, X> {
 
 //impl<T, U: FromDsl<T>> Dsl<U> for T {
 //}
-
-pub trait FromDsl<'state, T>: Sized {
-    fn take_from <'source: 'state> (
-        state: &'state T,
-        _token: &mut TokenIter<'source>
-    ) -> Perhaps<Self> {
-        unimplemented!()
-    }
-    fn take_from_or_fail <'source: 'state> (
-        state: &'state T,
-        token: &mut TokenIter<'source>,
-        error: impl Into<Box<dyn std::error::Error>>
-    ) -> Usually<Self> {
-        if let Some(value) = FromDsl::<T>::take_from(state, token)? {
-            Ok(value)
-        } else {
-            Result::Err(error.into())
-        }
-    }
-}