From 11f810a5f31cc94a9a146e8b228aae74a087af85 Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Mon, 1 Jul 2019 15:55:19 -0300
Subject: [PATCH] add basic parameter parsing

---
 examples/hello.v |  4 ++--
 src/ast.zig      | 10 ++++++++++
 src/parser.zig   | 47 ++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/examples/hello.v b/examples/hello.v
index 46cc8fd..93536f3 100644
--- a/examples/hello.v
+++ b/examples/hello.v
@@ -1,3 +1,3 @@
-fn main() {
-	println("hello world!");
+fn main(a int) {
+	// println("hello world!");
 }
diff --git a/src/ast.zig b/src/ast.zig
index a2b1834..365ef26 100644
--- a/src/ast.zig
+++ b/src/ast.zig
@@ -3,14 +3,24 @@ const tokens = @import("tokens.zig");
 const Token = tokens.Token;
 
 pub const NodeList = std.ArrayList(*Node);
+pub const ParamList = std.ArrayList(*ParamDecl);
 
 pub const NodeType = enum {
     Root,
     FnDecl,
 };
 
+pub const ParamDecl = struct {
+    param_name: Token,
+
+    // TODO types
+    param_type: Token,
+};
+
 pub const FnDecl = struct {
     func_name: Token,
+    params: ParamList,
+    body: NodeList,
 };
 
 pub const Node = union(NodeType) {
diff --git a/src/parser.zig b/src/parser.zig
index 76b8c59..cd15872 100644
--- a/src/parser.zig
+++ b/src/parser.zig
@@ -106,9 +106,17 @@ pub const Parser = struct {
         return Result.CompileError;
     }
 
-    fn mkFnDecl(self: *Parser, name: Token) !*ast.Node {
+    fn mkFnDecl(self: *Parser, name: Token, params: ast.ParamList) !*ast.Node {
         var node = try self.allocator.create(Node);
-        node.* = Node{ .FnDecl = ast.FnDecl{ .func_name = name } };
+        node.* = Node{
+            .FnDecl = ast.FnDecl{
+                .func_name = name,
+                .params = params,
+
+                // TODO replace by arg when statements work
+                .body = ast.NodeList.init(self.allocator),
+            },
+        };
         return node;
     }
 
@@ -117,7 +125,40 @@ pub const Parser = struct {
         var name = try self.consumeSingle(.Identifier);
         _ = try self.consumeSingle(.LeftParen);
 
-        return try self.mkFnDecl(name);
+        var param_list = ast.ParamList.init(self.allocator);
+
+        while (true) {
+            var tok = self.peek();
+
+            if (tok.ttype == .RightParen) break;
+            if (tok.ttype != .Identifier) {
+                try self.doError("expected identifier, got {}", tok.ttype);
+            }
+
+            var typetok = try self.nextToken();
+            if (typetok.ttype != .Identifier) {
+                try self.doError("expected identifier for type, got {}", typetok.ttype);
+            }
+
+            var param = try self.allocator.create(ast.ParamDecl);
+            param.* = ast.ParamDecl{ .param_name = tok, .param_type = typetok };
+
+            std.debug.warn("param! {}\n", param);
+            try param_list.append(param);
+        }
+
+        // function body
+        _ = try self.consumeSingle(.LeftBrace);
+        while (true) {
+            var tok = self.peek();
+            if (tok.ttype == .RightBrace) break;
+            // TODO statements?
+            //var node = self.processToken(tok);
+        }
+
+        _ = try self.consumeSingle(.RightBrace);
+
+        return try self.mkFnDecl(name, param_list);
     }
 
     fn processToken(self: *Parser, token: Token) !*ast.Node {