dsl: reduce number of lifetime arguments

dsl/src/dsl_provide.rs

@@ -1,30 +1,29 @@
 use crate::*;
 
-pub trait Dsl<Other> {
-    fn take <'state, 'source: 'state> (
-        &'state self,
-        token: &mut TokenIter<'source>
-    )
-        -> Perhaps<Other>;
-    fn take_or_fail <'state, 'source: 'state> (
-        &'state self,
-        token: &mut TokenIter<'source>,
-        error: impl Into<Box<dyn std::error::Error>>
-    ) -> Usually<Other> {
-        if let Some(value) = Dsl::<Other>::take(self, token)? {
+pub trait Dsl<Type> {
+    fn take <'source> (&self, token: &mut TokenIter<'source>) -> Perhaps<Type>;
+    fn take_or_fail <'source> (
+        &self, token: &mut TokenIter<'source>, error: impl Into<Box<dyn std::error::Error>>
+    ) -> Usually<Type> {
+        if let Some(value) = Dsl::<Type>::take(self, token)? {
             Ok(value)
         } else {
             Result::Err(error.into())
         }
     }
 }
-pub trait Namespace<'source, State>: Sized {
-    fn take_from <'state> (state: &'state State, token: &mut TokenIter<'source>)
+
+impl<Type: Namespace<State>, State> Dsl<Type> for State {
+    fn take <'source> (&self, token: &mut TokenIter<'source>) -> Perhaps<Type> {
+        Namespace::take_from(self, token)
+    }
+}
+
+pub trait Namespace<State>: Sized {
+    fn take_from <'source> (state: &State, token: &mut TokenIter<'source>)
         -> Perhaps<Self>;
-    fn take_from_or_fail <'state> (
-        state: &'state State,
-        token: &mut TokenIter<'source>,
-        error: impl Into<Box<dyn std::error::Error>>
+    fn take_from_or_fail <'source> (
+        state: &State, token: &mut TokenIter<'source>, error: impl Into<Box<dyn std::error::Error>>
     ) -> Usually<Self> {
         if let Some(value) = Namespace::<State>::take_from(state, token)? {
             Ok(value)
@@ -33,6 +32,7 @@ pub trait Namespace<'source, State>: Sized {
         }
     }
 }
+
 //impl<State: Dsl<T>, T> Namespace<State> for T {
     //fn take_from <'state, 'source: 'state> (state: &'state State, token: &mut TokenIter<'source>)
         //-> Perhaps<Self>
@@ -45,9 +45,9 @@ pub trait Namespace<'source, State>: Sized {
 /// specifying two types and providing an expression.
 #[macro_export] macro_rules! from_dsl {
     (@a: $T:ty: |$state:ident, $words:ident|$expr:expr) => {
-        impl<'source, State: Dsl<A>, A> Namespace<'source, State> for $T {
-            fn take_from <'state> (
-                $state: &'state State,
+        impl<State: Dsl<A>, A> Namespace<State> for $T {
+            fn take_from <'source> (
+                $state: &State,
                 $words: &mut TokenIter<'source>,
             ) -> Perhaps<$T> {
                 $expr
@@ -55,9 +55,9 @@ pub trait Namespace<'source, State>: Sized {
         }
     };
     (@ab: $T:ty: |$state:ident, $words:ident|$expr:expr) => {
-        impl<'source, State: Dsl<A> + Dsl<B>, A, B> Namespace<'source, State> for $T {
-            fn take_from <'state> (
-                $state: &'state State,
+        impl<State: Dsl<A> + Dsl<B>, A, B> Namespace<State> for $T {
+            fn take_from <'source> (
+                $state: &State,
                 $words: &mut TokenIter<'source>,
             ) -> Perhaps<$T> {
                 $expr
@@ -65,9 +65,9 @@ pub trait Namespace<'source, State>: Sized {
         }
     };
     ($T:ty: |$state:ident:$S:ty, $words:ident|$expr:expr) => {
-        impl<'source> Namespace<'source, $S> for $T {
-            fn take_from <'state> (
-                $state: &'state $S,
+        impl Namespace<$S> for $T {
+            fn take_from <'source> (
+                $state: &$S,
                 $words: &mut TokenIter<'source>,
             ) -> Perhaps<$T> {
                 $expr