From 7ba3f96d49489aec9ff4a536c2df416287e49aca Mon Sep 17 00:00:00 2001
From: Greg Brown <gmb60@cam.ac.uk>
Date: Mon, 1 Mar 2021 13:36:55 +0000
Subject: Initial work on charsets

---
 src/lower/mod.rs | 56 ++++++++++++++++++++++++++++++--------------------------
 1 file changed, 30 insertions(+), 26 deletions(-)

(limited to 'src/lower')

diff --git a/src/lower/mod.rs b/src/lower/mod.rs
index dcd0f1f..45be7aa 100644
--- a/src/lower/mod.rs
+++ b/src/lower/mod.rs
@@ -300,17 +300,19 @@ impl Backend for RustBackend {
             .enumerate()
             .find(|(_, ty)| ty.nullable())
             .map(|(idx, _)| name_parts[idx].clone());
-        let (first_alts, firsts): (Vec<_>, Vec<_>) = tys
-            .iter()
-            .map(Type::first_set)
-            .cloned()
-            .enumerate()
-            .filter(|(_, fs)| !fs.is_empty())
-            .map(|(idx, fs)| {
-                let fs = fs.into_iter();
-                (name_parts[idx].clone(), quote! {#(Some(#fs))|*})
-            })
-            .unzip();
+        todo!();
+        // let (first_alts, firsts): (Vec<_>, Vec<_>) = tys
+        //     .iter()
+        //     .map(Type::first_set)
+        //     .cloned()
+        //     .enumerate()
+        //     .filter(|(_, fs)| !fs.is_empty())
+        //     .map(|(idx, fs)| {
+        //         let fs = fs.into_iter();
+        //         // (name_parts[idx].clone(), quote! {#(Some(#fs))|*})
+        //         todo!()
+        //     })
+        //     .unzip();
         let all_firsts = tys
             .iter()
             .map(Type::first_set)
@@ -336,25 +338,27 @@ impl Backend for RustBackend {
                 quote_spanned! {span=>
                     impl Parse for #name {
                         fn take<P: Parser + ?Sized>(input: &mut P) -> Result<Self, TakeError> {
-                            match input.peek() {
-                                #(#firsts => Ok(Self::#first_alts(input.take()?)),)*
-                                _ => Ok(Self::#nullable(input.take()?))
-                            }
+                            todo!()
+                            // match input.peek() {
+                            //     #(#firsts => Ok(Self::#first_alts(input.take()?)),)*
+                            //     _ => Ok(Self::#nullable(input.take()?))
+                            // }
                         }
                     }
                 }
             } else {
-                quote_spanned! {span=>
-                    impl Parse for #name {
-                        fn take<P: Parser + ?Sized>(input: &mut P) -> Result<Self, TakeError> {
-                            match input.peek() {
-                                #(#firsts => Ok(Self::#first_alts(input.take()?)),)*
-                                Some(c) => Err(TakeError::BadBranch(input.pos(), c, &[#(#all_firsts),*])),
-                                None => Err(TakeError::EndOfStream(input.pos()))
-                            }
-                        }
-                    }
-                }
+                todo!()
+                // quote_spanned! {span=>
+                //     impl Parse for #name {
+                //         fn take<P: Parser + ?Sized>(input: &mut P) -> Result<Self, TakeError> {
+                //             match input.peek() {
+                //                 #(#firsts => Ok(Self::#first_alts(input.take()?)),)*
+                //                 Some(c) => Err(TakeError::BadBranch(input.pos(), c, &[#(#all_firsts),*])),
+                //                 None => Err(TakeError::EndOfStream(input.pos()))
+                //             }
+                //         }
+                //     }
+                // }
             });
 
         if ids.iter().all(|id| self.can_char.contains(id)) {
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