From b81e250fab7f54838a9b205e51a49bd5b932c618 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Edvard=20Th=C3=B6rnros?= <edvard.thornros@gmail.com>
Date: Mon, 11 Jan 2021 15:08:35 +0100
Subject: If-statements

---
 src/compiler.rs  | 29 ++++++++++++++++++++++++-----
 src/tokenizer.rs |  5 +++++
 2 files changed, 29 insertions(+), 5 deletions(-)

(limited to 'src')

diff --git a/src/compiler.rs b/src/compiler.rs
index 8275618..4bd519d 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -347,6 +347,29 @@ impl Compiler {
         expect!(self, Token::RightBrace, "Expected '}' at end of block.");
     }
 
+    fn if_statment(&mut self, block: &mut Block) {
+        expect!(self, Token::If, "Expected 'if' at start of if-statement.");
+        self.expression(block);
+        let jump = block.add(Op::Illegal, self.line());
+        self.scope(block);
+
+        if Token::Else == self.peek() {
+            let else_jmp = block.add(Op::Illegal, self.line());
+            block.patch(Op::JmpFalse(block.curr()), jump);
+
+            self.eat();
+            match self.peek() {
+                Token::If => self.if_statment(block),
+                Token::LeftBrace => self.scope(block),
+                _ => error!(self, "Epected 'if' or '{' after else."),
+            }
+            block.patch(Op::Jmp(block.curr()), else_jmp);
+        } else {
+            block.patch(Op::JmpFalse(block.curr()), jump);
+        }
+
+    }
+
     fn statement(&mut self, block: &mut Block) {
         self.clear_panic();
 
@@ -381,11 +404,7 @@ impl Compiler {
             }
 
             (Token::If, _, _, _) => {
-                self.eat();
-                self.expression(block);
-                let jump = block.add(Op::Illegal, self.line());
-                self.scope(block);
-                block.patch(Op::JmpFalse(block.curr()), jump);
+                self.if_statment(block);
             }
 
             (Token::LeftBrace, _, _, _) => {
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index 18e1aa1..8778430 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -20,6 +20,8 @@ pub enum Token {
 
     #[token("if")]
     If,
+    #[token("else")]
+    Else,
     #[token("for")]
     For,
     #[token("in")]
@@ -64,8 +66,11 @@ pub enum Token {
     EqualEqual,
     #[token("!=")]
     NotEqual,
+
     #[token("<=>")]
     AssertEqual,
+    #[token("<!>")]
+    Unreachable,
 
     #[token("(")]
     LeftParen,
-- 
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