Add function calling syntax

1 files changed, 34 insertions, 6 deletions

diff --git a/src/com/craftinginterpreters/lox/Parser.java b/src/com/craftinginterpreters/lox/Parser.java
index 7d7b27a..df3ce3f 100644
--- a/src/com/craftinginterpreters/lox/Parser.java
+++ b/src/com/craftinginterpreters/lox/Parser.java
@@ -84,13 +84,11 @@ class Parser {
         Stmt body = statement();
 
         if (increment != null) {
-            body = new Stmt.Block(
-                                  Arrays.asList(
-                                                body,
-                            new Stmt.Expression(increment)));
+            body = new Stmt.Block(Arrays.asList(body, new Stmt.Expression(increment)));
         }
 
-        if (condition == null) condition = new Expr.Literal(true);
+        if (condition == null)
+            condition = new Expr.Literal(true);
         body = new Stmt.While(condition, body);
 
         if (initializer != null) {
@@ -255,7 +253,37 @@ class Parser {
             return new Expr.Unary(operator, right);
         }
 
-        return primary();
+        return call();
+    }
+
+    private Expr finishCall(Expr callee) {
+        List<Expr> arguments = new ArrayList<>();
+        if (!check(RIGHT_PAREN)) {
+            do {
+                if (arguments.size() >= 255) {
+                    error(peek(), "Can't have more than 255 arguments.");
+                }
+                arguments.add(expression());
+            } while (match(COMMA));
+        }
+
+        Token paren = consume(RIGHT_PAREN, "Expect ')' after arguments.");
+
+        return new Expr.Call(callee, paren, arguments);
+    }
+
+    private Expr call() {
+        Expr expr = primary();
+
+        while (true) {
+            if (match(LEFT_PAREN)) {
+                expr = finishCall(expr);
+            } else {
+                break;
+            }
+        }
+
+        return expr;
     }
 
     private Expr primary() {