From d16a0c9380a3972b4b168130ef92b74bdc9c4b4a Mon Sep 17 00:00:00 2001
From: greg <greg.shuflin@protonmail.com>
Date: Sun, 1 Oct 2017 12:55:28 -0700
Subject: [PATCH] Evaluation of literals

---
 src/schala_lang/eval.rs    | 49 ++++++++++++++++++++++++++++++++------
 src/schala_lang/parsing.rs |  6 ++---
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/src/schala_lang/eval.rs b/src/schala_lang/eval.rs
index 1c8c096..19b20ee 100644
--- a/src/schala_lang/eval.rs
+++ b/src/schala_lang/eval.rs
@@ -1,22 +1,57 @@
-use schala_lang::parsing::AST;
+use schala_lang::parsing::{AST, Statement, Declaration, Expression, ExpressionType};
 
 pub struct ReplState {
 }
 
-pub enum TypeCheck {
-  OK,
-  Error(String)
-}
-
 impl ReplState {
   pub fn new() -> ReplState {
     ReplState { }
   }
 
   pub fn evaluate(&mut self, ast: AST) -> String {
-    format!("Evaluated AST: {:?}", ast)
+    let mut acc = String::new();
+    for statement in ast.0 {
+      if let Some(output) = self.eval_statement(statement) {
+        acc.push_str(&output);
+        acc.push_str("\n");
+      }
+    }
+    format!("{}", acc)
+  }
+}
+
+impl ReplState {
+  fn eval_statement(&mut self, statement: Statement) -> Option<String> {
+    match statement {
+      Statement::ExpressionStatement(expr) => self.eval_expr(expr),
+      Statement::Declaration(decl) => self.eval_decl(decl),
+    }
   }
 
+  fn eval_decl(&mut self, decl: Declaration) -> Option<String> {
+    Some("UNIMPLEMENTED".to_string())
+  }
+
+  fn eval_expr(&mut self, expr: Expression) -> Option<String> {
+    use self::ExpressionType::*;
+
+    let expr_type = expr.0;
+    Some(match expr_type {
+      IntLiteral(n) => format!("{}", n),
+      FloatLiteral(f) => format!("{}", f),
+      StringLiteral(s) => format!("{}", s),
+      BoolLiteral(b) => format!("{}", b),
+      _ => format!("UNIMPLEMENTED"),
+    })
+  }
+}
+
+pub enum TypeCheck {
+  OK,
+  Error(String)
+}
+
+impl ReplState {
   pub fn type_check(&mut self, _ast: &AST) -> TypeCheck {
     //TypeCheck::Error("type lol".to_string())
     TypeCheck::OK
diff --git a/src/schala_lang/parsing.rs b/src/schala_lang/parsing.rs
index 3932873..092d6b2 100644
--- a/src/schala_lang/parsing.rs
+++ b/src/schala_lang/parsing.rs
@@ -383,7 +383,7 @@ macro_rules! expect {
 }
 
 #[derive(Debug, PartialEq)]
-pub struct AST(Vec<Statement>);
+pub struct AST(pub Vec<Statement>);
 
 #[derive(Debug, PartialEq)]
 pub enum Statement {
@@ -411,7 +411,7 @@ pub enum Declaration {
 }
 
 #[derive(Debug, PartialEq)]
-pub struct TypeBody(Vec<Variant>);
+pub struct TypeBody(pub Vec<Variant>);
 
 #[derive(Debug, PartialEq)]
 pub enum Variant {
@@ -421,7 +421,7 @@ pub enum Variant {
 }
 
 #[derive(Debug, PartialEq)]
-pub struct Expression(ExpressionType, Option<TypeAnno>);
+pub struct Expression(pub ExpressionType, pub Option<TypeAnno>);
 
 #[derive(Debug, PartialEq)]
 pub enum TypeAnno {