wip: fix(dsl): maybe getting somewhere?

proc/src/proc_command.rs

@@ -84,7 +84,7 @@ impl ToTokens for CommandDef {
                         let mut out = TokenStream2::new();
                         for (arg, _ty) in arm.args() {
                             write_quote_to(&mut out, quote! {
-                                #arg: Dsl::try_provide(self, words)?,
+                                #arg: DslFrom::dsl_from(self, words, ||"command error")?,
                             });
                         }
                         out
@@ -93,7 +93,7 @@ impl ToTokens for CommandDef {
                 out
             };
             write_quote(quote! {
-                Some(::tengri::dsl::Token { value: ::tengri::dsl::Value::Key(#key), .. }) => {
+                Some(::tengri::dsl::Token { value: ::tengri::dsl::DslVal::Key(#key), .. }) => {
                     let mut words = words.clone();
                     Some(#command_enum::#variant)
                 },
@@ -149,10 +149,12 @@ impl ToTokens for CommandDef {
                 }
             }
             /// Generated by [tengri_proc::command].
-            impl ::tengri::dsl::Dsl<#state> for #command_enum {
-                fn try_provide (state: &#state, mut words: ::tengri::dsl::Ast) -> Perhaps<Self> {
-                    let mut words = words.clone();
-                    let token = words.next();
+            impl ::tengri::dsl::DslFrom<#state> for #command_enum {
+                fn try_dsl_from (
+                    state: &#state,
+                    value: &impl ::tengri::dsl::Dsl
+                ) -> Perhaps<Self> {
+                    use ::tengri::dsl::DslVal::*;
                     todo!()//Ok(match token { #(#matchers)* _ => None })
                 }
             }

proc/src/proc_expose.rs

@@ -63,8 +63,8 @@ impl ToTokens for ExposeImpl {
             let formatted_type = format!("{}", quote! { #t }); 
             let predefined = match formatted_type.as_str() {
                 "bool" => quote! {
-                    Some(::tengri::dsl::Value::Sym(":true"))  => true,
-                    Some(::tengri::dsl::Value::Sym(":false")) => false,
+                    Some(::tengri::dsl::DslVal::Sym(":true"))  => true,
+                    Some(::tengri::dsl::DslVal::Sym(":false")) => false,
                 },
                 "u8" | "u16" | "u32" | "u64" | "usize" |
                 "i8" | "i16" | "i32" | "i64" | "isize" => {
@@ -73,7 +73,7 @@ impl ToTokens for ExposeImpl {
                         Span::call_site()
                     );
                     quote! {
-                        Some(::tengri::dsl::Value::Num(n)) => TryInto::<#t>::try_into(n)
+                        Some(::tengri::dsl::DslVal::Num(n)) => TryInto::<#t>::try_into(*n)
                             .unwrap_or_else(|_|panic!(#num_err)),
                     }
                 },
@@ -81,17 +81,13 @@ impl ToTokens for ExposeImpl {
             };
             let values = variants.iter().map(|(key, value)|{
                 let key = LitStr::new(&key, Span::call_site());
-                quote! { Some(::tengri::dsl::Value::Sym(#key)) => state.#value(), }
+                quote! { Some(::tengri::dsl::DslVal::Sym(#key)) => state.#value(), }
             });
             write_quote_to(out, quote! {
                 /// Generated by [tengri_proc::expose].
-                impl ::tengri::dsl::Dsl<#state> for #t {
-                    fn try_provide (state: &#state, mut words: ::tengri::dsl::Ast) -> Perhaps<Self> {
-                        Ok(Some(match words.next().map(|x|x.value) {
-                            #predefined
-                            #(#values)*
-                            _ => return Ok(None)
-                        }))
+                impl ::tengri::dsl::DslFrom<#state> for #t {
+                    fn try_dsl_from (state: &#state, value: &impl Dsl) -> Perhaps<Self> {
+                        Ok(Some(match value { #predefined #(#values)* _ => return Ok(None) }))
                     }
                 }
             });

proc/src/proc_view.rs

@@ -44,15 +44,16 @@ impl ToTokens for ViewDef {
         // Expressions are handled by built-in functions
         // that operate over constants and symbols.
         let builtin = builtins_with_boxes_output(quote! { #output }).map(|builtin|quote! {
-            ::tengri::dsl::Value::Exp(_, expr) => return Ok(Some(
-                #builtin::try_provide(state, expr, ||"failed to load builtin")?.boxed()
+            ::tengri::dsl::DslVal::Exp(_, expr) => return Ok(Some(
+                #builtin::dsl_from(self, expr, ||Box::new("failed to load builtin".into()))?
+                    .boxed()
             )),
         });
         // Symbols are handled by user-taked functions
         // that take no parameters but `&self`.
         let exposed = exposed.iter().map(|(key, value)|write_quote(quote! {
-            ::tengri::dsl::Value::Sym(#key) => return Ok(Some(
-                state.#value().boxed()
+            ::tengri::dsl::DslVal::Sym(#key) => return Ok(Some(
+                self.#value().boxed()
             )),
         }));
         write_quote_to(out, quote! {
@@ -63,15 +64,14 @@ impl ToTokens for ViewDef {
             /// Makes [#self_ty] able to construct the [Render]able
             /// which might correspond to a given [TokenStream],
             /// while taking [#self_ty]'s state into consideration.
-            impl<'state> ::tengri::dsl::Dsl<Box<dyn Render<#output> + 'state>> for #self_ty {
-                fn try_provide (state: &'state #self_ty, mut words: ::tengri::dsl::Ast) ->
-                    Perhaps<Box<dyn Render<#output> + 'state>>
+            impl<'state> ::tengri::dsl::DslInto<
+                Box<dyn ::tengri::output::Render<#output> + 'state>
+            > for #self_ty {
+                fn try_dsl_into (&self, dsl: &impl ::tengri::dsl::Dsl)
+                    -> Perhaps<Box<dyn ::tengri::output::Render<#output> + 'state>>
                 {
-                    Ok(if let Some(::tengri::dsl::Token { value, .. }) = words.peek() {
-                        match value { #(#builtin)* #(#exposed)* _ => None }
-                    } else {
-                        None
-                    })
+                    use ::tengri::dsl::DslVal::*;
+                    Ok(match dsl.val() { #(#builtin)* #(#exposed)* _ => return Ok(None) })
                 }
             }
         })