add better ast printing

src/ast.zig

@@ -43,3 +43,28 @@ pub fn mkRoot(allocator: *std.mem.Allocator) !*Node {
     node.* = Node{ .Root = NodeList.init(allocator) };
     return node;
 }
+
+fn print(ident: usize, comptime fmt: []const u8, args: ...) void {
+    var i: usize = 0;
+    while (i < ident) : (i += 1) {
+        std.debug.warn("\t");
+    }
+
+    std.debug.warn(fmt, args);
+}
+
+pub fn printNode(node: *Node, ident: usize) void {
+    switch (node.*) {
+        .FnDecl => |proto| {
+            print(ident, "FnDecl name='{}'\n", proto.func_name.lexeme);
+        },
+        .Root => {
+            for (node.Root.toSlice()) |child| {
+                printNode(child, ident + 1);
+            }
+        },
+        else => {
+            print(ident, "unknown node: {}\n", node);
+        },
+    }
+}

src/parser.zig

@@ -233,6 +233,12 @@ pub const Parser = struct {
             .Fn => blk: {
                 _ = try self.consumeSingle(.Fn);
                 var name = try self.consumeSingle(.Identifier);
+                _ = try self.consumeSingle(.LeftParen);
+                // TODO paramlist
+                _ = try self.consumeSingle(.RightParen);
+                _ = try self.consumeSingle(.LeftBrace);
+                // TODO block
+                _ = try self.consumeSingle(.RightBrace);
                 std.debug.warn("!fn name: {}\n", name);
                 break :blk try self.mkFnDecl(
                     name,

src/runner.zig

@@ -48,9 +48,8 @@ pub const Runner = struct {
 
         var it = root.Root.iterator();
 
-        while (it.next()) |node| {
-            std.debug.warn("{}\n", node.*);
-        }
+        std.debug.warn("parse tree\n");
+        ast.printNode(root, 0);
 
         return Result.Ok;
     }