Starting basic type stuff

TODO.md

@@ -5,6 +5,17 @@
 
 * idea for Schala - scoped types - be able to define a quick enum type scoped to a function ro something, that only is meant to be used as a quick bespoke interface between two other things
 
+* another idea, allow:
+type enum {
+  type enum MySubVariant {
+    SubVariant1, SubVariant2, etc.
+    }
+ Variant1(MySubVariant),
+ Variant2(...),
+ }
+
+
+
 * idea for Schala: both currying *and* default arguments!
         ex. fn a(b: Int, c:Int, d:Int = 1) -> Int
             a(1,2) : Int

src/schala_lang/typechecking.rs

@@ -4,9 +4,14 @@ use schala_lang::parsing;
 
 pub struct TypeContext { }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 pub enum Type {
   Unit,
+  Int,
+  Float,
+  StringT,
+  Bool,
+  Custom(Rc<String>),
   Void
 }
 
@@ -25,9 +30,11 @@ impl TypeContext {
     Ok(ret_type)
   }
   fn type_check_statement(&mut self, statement: &parsing::Statement) -> TypeResult<Type> {
+    println!("statement should be: {:?}", statement);
+
     use self::parsing::Statement::*;
     match statement {
-      &ExpressionStatement(ref expr) => self.type_check_expression(expr),
+      &ExpressionStatement(ref expr) => self.type_infer(expr),
       &Declaration(ref decl) => self.type_check_declaration(decl),
     }
   }
@@ -35,9 +42,24 @@ impl TypeContext {
     use self::Type::*;
     Ok(Unit)
   }
-  fn type_check_expression(&mut self, expr: &parsing::Expression) -> TypeResult<Type> {
+  fn type_infer(&mut self, expr: &parsing::Expression) -> TypeResult<Type> {
+    use self::parsing::Expression;
+    use self::parsing::ExpressionType::*;
     use self::Type::*;
-    Ok(Void)
+    match expr {
+      &Expression(ref e, Some(ref ty)) => Err(format!("Anno not implemented")),
+      &Expression(ref e, None) => match e {
+        &IntLiteral(_) => Ok(Int),
+        &FloatLiteral(_) => Ok(Float),
+        &StringLiteral(_) => Ok(StringT),
+        &BoolLiteral(_) => Ok(Bool),
+        _ => Err(format!("Type not yet implemented"))
+      }
+    }
+  }
+  fn unify(&mut self, t1: Type, t2: Type) -> TypeResult<Type> {
+    use self::Type::*;
+    Ok(Unit)
   }
 }