Cargo.lock

@@ -922,12 +922,21 @@ dependencies = [
  "peg",
  "pretty_assertions",
  "radix_trie",
+ "schala-lang-codegen",
  "schala-repl",
  "stopwatch",
  "take_mut",
  "test-case",
 ]
 
+[[package]]
+name = "schala-lang-codegen"
+version = "0.1.0"
+dependencies = [
+ "quote 0.6.13",
+ "syn 0.15.44",
+]
+
 [[package]]
 name = "schala-repl"
 version = "0.1.0"

Cargo.toml

@@ -9,7 +9,7 @@ resolver = "2"
 getopts = "0.2.21"
 
 schala-repl = { path = "schala-repl" }
-schala-lang = { path = "schala-lang" }
+schala-lang = { path = "schala-lang/language" }
 # maaru-lang = { path = "maaru" }
 # rukka-lang = { path = "rukka" }
 # robo-lang = { path = "robo" }

schala-lang/codegen/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "schala-lang-codegen"
+version = "0.1.0"
+authors = ["greg <greg.shuflin@protonmail.com>"]
+edition = "2018"
+resolver = "2"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = { version = "0.15.12", features = ["full", "extra-traits", "fold"] }
+quote = "0.6.8"

schala-lang/codegen/src/lib.rs

@@ -0,0 +1,53 @@
+#![feature(box_patterns)]
+#![recursion_limit="128"]
+extern crate proc_macro;
+#[macro_use]
+extern crate quote;
+#[macro_use]
+extern crate syn;
+
+use self::proc_macro::TokenStream;
+use self::syn::fold::Fold;
+
+struct RecursiveDescentFn {
+}
+
+impl Fold for RecursiveDescentFn {
+  fn fold_item_fn(&mut self, mut i: syn::ItemFn) -> syn::ItemFn {
+    let box block = i.block;
+    let ident = &i.ident;
+
+    let new_block: syn::Block = parse_quote! {
+      {
+        let next_token_before_parse = self.token_handler.peek();
+        let record = ParseRecord {
+          production_name: stringify!(#ident).to_string(),
+          next_token: format!("{}", next_token_before_parse.to_string_with_metadata()),
+          level: self.parse_level,
+        };
+        self.parse_level += 1;
+        self.parse_record.push(record);
+        let result = { #block };
+
+        if self.parse_level != 0 {
+          self.parse_level -= 1;
+        }
+
+        result.map_err(|mut parse_error: ParseError| {
+          parse_error
+        })
+      }
+    };
+    i.block = Box::new(new_block);
+    i
+  }
+}
+
+#[proc_macro_attribute]
+pub fn recursive_descent_method(_attr: TokenStream, item: TokenStream) -> TokenStream {
+
+  let input: syn::ItemFn = parse_macro_input!(item as syn::ItemFn);
+  let mut folder = RecursiveDescentFn {};
+  let output = folder.fold_item_fn(input);
+  TokenStream::from(quote!(#output))
+}

schala-lang/language/Cargo.toml

@@ -18,7 +18,8 @@ assert_matches = "1.5"
 peg = { git = "https://github.com/kevinmehall/rust-peg", rev = "960222580c8da25b17d32c2aae6f52f902728b62" }
 
 
-schala-repl = { path = "../schala-repl" }
+schala-lang-codegen = { path = "../codegen" }
+schala-repl = { path = "../../schala-repl" }
 
 [dev-dependencies]
 test-case = "1.2.0"

schala-lang/language/src/lib.rs

@@ -7,6 +7,7 @@
 //! `ProgrammingLanguageInterface` and the chain of compiler passes for it.
 
 extern crate derivative;
+extern crate schala_lang_codegen;
 extern crate schala_repl;
 
 #[macro_use]