Adding proc macro for codegen

This should hopefully make the compiler pass thing I want to do possible

Cargo.toml

@@ -6,6 +6,7 @@ authors = ["greg <greg.shuflin@protonmail.com>"]
 [dependencies]
 
 schala-repl = { path = "schala-repl" }
+schala-codegen = { path = "schala-codegen" }
 maaru-lang = { path = "maaru" }
 rukka-lang = { path = "rukka" }
 robo-lang = { path = "robo" }

TODO.md

@@ -1,6 +1,15 @@
 
 # TODO Items
 
+
+- sketch of an idea for the REPL:
+        -each compiler pass should be a (procedural?) macro like
+        compiler_pass!("parse", dataproducts: ["ast", "parse_tree"], {
+         match parsing::parse(INPUT) {
+           Ok(
+                PASS.add_artifact(
+        }
+
 -should have an Idris-like `cast To From` function
 
 - REPL:

schala-codegen/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "schala-codegen"
+version = "0.1.0"
+authors = ["greg <greg.shuflin@protonmail.com>"]
+
+[dependencies]
+
+[lib]
+proc-macro = true

schala-codegen/src/lib.rs

@@ -0,0 +1,16 @@
+#![feature(proc_macro)]
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn print_a_thing(_input: TokenStream) -> TokenStream {
+  "println!(\"Invoked from a proc macro\");".parse().unwrap()
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}

schala-lang/Cargo.toml

@@ -10,3 +10,4 @@ maplit = "*"
 lazy_static = "0.2.8"
 
 schala-repl = { path = "../schala-repl" }
+schala-codegen = { path = "../schala-codegen" }

schala-lang/src/lib.rs

@@ -1,4 +1,5 @@
 #![feature(slice_patterns, box_patterns, box_syntax)]
+#![feature(proc_macro)]
 extern crate itertools;
 #[macro_use]
 extern crate lazy_static;
@@ -6,6 +7,7 @@ extern crate lazy_static;
 extern crate maplit;
 
 extern crate schala_repl;
+extern crate schala_codegen;
 
 use itertools::Itertools;
 use schala_repl::{ProgrammingLanguageInterface, EvalOptions, TraceArtifact, UnfinishedComputation, FinishedComputation};
@@ -47,6 +49,8 @@ impl ProgrammingLanguageInterface for Schala {
   }
 
   fn execute(&mut self, input: &str, options: &EvalOptions) -> FinishedComputation {
+    schala_codegen::print_a_thing!();
+
     let mut evaluation = UnfinishedComputation::default();
 
     //tokenzing