Implement If expression supportdev-easy

I forgor

1 files changed, 30 insertions, 3 deletions

diff --git a/compiler/src/ast/parser.rs b/compiler/src/ast/parser.rs
index 12a6f0d..88ba8c7 100644
--- a/compiler/src/ast/parser.rs
+++ b/compiler/src/ast/parser.rs
@@ -244,14 +244,40 @@ where
         Ok(Spanned::new(let_vars, span))
     }
 
+    fn parse_if(&mut self, open_span: Span) -> Result<Spanned<Expr>, Spanned<Error>> {
+        self.consume()?;
+
+        let condition = self.parse_expr()?.map(Into::into);
+        let then_expr = self.parse_expr()?.map(Into::into);
+        let else_expr = match self.peek_token()?.inner {
+            Token::RightPar => {
+                self.consume()?;
+                None
+            }
+            _ => {
+                let expr = self.parse_expr()?.map(Into::into);
+                self.require_right_par()?;
+                Some(expr)
+            }
+        };
+
+        let if_stmt = Expr::If {
+            condition,
+            then_expr,
+            else_expr,
+        };
+        let span = Span::new(open_span.start, self.last_token_span.end);
+        Ok(Spanned::new(if_stmt, span))
+    }
+
     fn parse_for(&mut self, open_span: Span) -> Result<Spanned<Expr>, Spanned<Error>> {
         self.consume()?;
 
         let loop_var = self.parse_sym()?.map(Into::into);
         self.require_sym("from")?;
-        let from = self.parse_expr()?.map(Box::new);
+        let from = self.parse_expr()?.map(Into::into);
         self.require_sym("to")?;
-        let to = self.parse_expr()?.map(Box::new);
+        let to = self.parse_expr()?.map(Into::into);
         let body = self.parse_body(open_span, true)?;
 
         let for_loop = Expr::For {
@@ -268,7 +294,7 @@ where
         self.consume()?;
 
         let target_var = self.parse_sym()?.map(Into::into);
-        let expr = self.parse_expr()?.map(Box::new);
+        let expr = self.parse_expr()?.map(Into::into);
         self.require_right_par()?;
 
         let set = Expr::Set { target_var, expr };
@@ -312,6 +338,7 @@ where
             "fn" => self.parse_fn(open_span),
             "const" => self.parse_const(open_span),
             "let" => self.parse_let(open_span),
+            "if" => self.parse_if(open_span),
             "for" => self.parse_for(open_span),
             "set" => self.parse_set(open_span),
             "do" => self.parse_do(open_span),