From a3b37ae6032a1cac9794f35ca1c264cb8199cf88 Mon Sep 17 00:00:00 2001
From: Huzaifa Raghav <huzaifaraghav2000@gmail.com>
Date: Thu, 11 Apr 2024 23:59:36 +0800
Subject: [PATCH] Add if-else data (WIP)

---
 compiler/oxidate/src/compiler.rs |  1 +
 src/parser/src/if_else.rs        | 39 +++++++++++++++++++++++++++++---
 src/parser/src/seq.rs            |  2 +-
 src/parser/src/structs.rs        | 30 ++++++++++++++++++++++++
 src/types/src/type_checker.rs    |  1 +
 5 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/compiler/oxidate/src/compiler.rs b/compiler/oxidate/src/compiler.rs
index e7f2a1c..f1c12d7 100644
--- a/compiler/oxidate/src/compiler.rs
+++ b/compiler/oxidate/src/compiler.rs
@@ -86,6 +86,7 @@ impl Compiler {
             Expr::BlockExpr(blk) => {
                 Compiler::compile_block(blk, arr)?;
             }
+            _ => todo!(),
         }
 
         Ok(())
diff --git a/src/parser/src/if_else.rs b/src/parser/src/if_else.rs
index 944f901..7e9e8df 100644
--- a/src/parser/src/if_else.rs
+++ b/src/parser/src/if_else.rs
@@ -1,6 +1,7 @@
 use crate::Decl;
 // use crate::Decl::*;
 use crate::Expr;
+use crate::IfElseData;
 use crate::ParseError;
 use crate::Parser;
 // use crate::{BinOpType, UnOpType};
@@ -15,11 +16,33 @@ impl<'inp> Parser<'inp> {
         self.consume_token_type(Token::OpenParen, "Expected open parenthesis")?;
         dbg!("OK", &self.prev_tok);
 
-        let cond = self.parse_expr(min_bp);
+        let cond = self.parse_expr(min_bp)?.to_expr()?;
         dbg!(&cond); // got cond
 
         dbg!("peek after:", &self.lexer.peek()); // OpenBrace
-        Ok(Decl::ExprStmt(Expr::Bool(true)))
+
+        // go past OpenBrace, put in prev_tok
+        self.consume_token_type(
+            Token::OpenBrace,
+            &format!("Expected {} for if block", Token::OpenBrace),
+        )?;
+
+        let if_blk = self.parse_blk(min_bp)?.to_block()?;
+
+        dbg!("after parse_blk", &if_blk);
+
+        dbg!("peek after parse_blk", &self.lexer.peek());
+
+        let stmt = IfElseData {
+            cond,
+            if_blk,
+            else_blk: None,
+        };
+
+        let expr = Expr::IfElseExpr(Box::new(stmt));
+
+        // parse else blk if avail
+        Ok(Decl::ExprStmt(expr))
     }
 }
 
@@ -31,9 +54,19 @@ mod tests {
     fn parse_if_basic() {
         let t = r"
         if (true) {
-
+            30;
+            40;
         }
         ";
         // test_parse(t, "");
+
+        // let t = r"
+        // if (true) {
+        //     30;
+        // } else {
+        //     40;
+        // }
+        // ";
+        // test_parse(t, "");
     }
 }
diff --git a/src/parser/src/seq.rs b/src/parser/src/seq.rs
index 45021b8..664d2b7 100644
--- a/src/parser/src/seq.rs
+++ b/src/parser/src/seq.rs
@@ -22,7 +22,7 @@ impl<'inp> Parser<'inp> {
             // dbg!("prev_tok:", &self.prev_tok);
 
             let expr = self.parse_decl()?;
-            // dbg!("Got expr:", &expr);
+            dbg!("Got expr:", &expr);
             // dbg!("Peek:", &self.lexer.peek());
 
             // end of block: lexer empty OR curly brace (TODO add curly later)
diff --git a/src/parser/src/structs.rs b/src/parser/src/structs.rs
index 0865443..101e206 100644
--- a/src/parser/src/structs.rs
+++ b/src/parser/src/structs.rs
@@ -65,6 +65,7 @@ pub enum Expr {
     UnOpExpr(UnOpType, Box<Expr>),
     BinOpExpr(BinOpType, Box<Expr>, Box<Expr>),
     BlockExpr(BlockSeq), // expr can be a block
+    IfElseExpr(Box<IfElseData>),
 }
 
 impl Display for Expr {
@@ -81,6 +82,8 @@ impl Display for Expr {
             }
             Expr::Symbol(val) => val.to_string(),
             Expr::BlockExpr(seq) => format!("{{ {} }}", seq),
+            // Expr::BlockExpr(seq) => seq.to_string(),
+            Expr::IfElseExpr(expr) => expr.to_string(),
         };
 
         write!(f, "{}", string)
@@ -118,6 +121,24 @@ impl Display for AssignStmt {
     }
 }
 
+#[derive(Debug, Clone)]
+pub struct IfElseData {
+    pub cond: Expr,
+    pub if_blk: BlockSeq,
+    pub else_blk: Option<BlockSeq>,
+}
+
+impl Display for IfElseData {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut s = format!("if {} {}", self.cond, self.if_blk);
+        if let Some(ref else_blk) = self.else_blk {
+            s.push(' ');
+            s.push_str(&format!("else {}", else_blk));
+        }
+
+        write!(f, "{}", s)
+    }
+}
 // Later: LetStmt, IfStmt, FnDef, etc.
 #[derive(Debug, Clone)]
 pub enum Decl {
@@ -140,6 +161,15 @@ impl Decl {
             Self::ExprStmt(expr) => Ok(expr.clone()),
         }
     }
+
+    pub fn to_block(&self) -> Result<BlockSeq, ParseError> {
+        if let Self::ExprStmt(Expr::BlockExpr(seq)) = &self {
+            return Ok(seq.clone());
+        }
+
+        let e = format!("Expected block but got '{}'", self);
+        Err(ParseError::new(&e))
+    }
 }
 
 impl Display for Decl {
diff --git a/src/types/src/type_checker.rs b/src/types/src/type_checker.rs
index 3cea2f5..fcafd8a 100644
--- a/src/types/src/type_checker.rs
+++ b/src/types/src/type_checker.rs
@@ -184,6 +184,7 @@ impl<'prog> TypeChecker<'prog> {
                 return self.check_binop(op, lhs, rhs);
             }
             Expr::BlockExpr(blk) => self.check_block(blk)?,
+            _ => todo!(),
         };
 
         if local_errs.is_ok() {