From c0c93183cb693afc291320b4b1114476a2b1fe30 Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Sun, 25 Aug 2019 23:16:13 -0300
Subject: [PATCH] add return statements

---
 examples/hello.v |  2 ++
 src/ast.zig      | 25 +++++++++++++++++++++++++
 src/parser.zig   | 11 +++++++++--
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/examples/hello.v b/examples/hello.v
index 8d31672..9a3e886 100644
--- a/examples/hello.v
+++ b/examples/hello.v
@@ -32,4 +32,6 @@ fn main(a int) int {
 	}
 
 	cock_and_ball_torture('cbt', 1, 2, 3)
+
+	return 23
 }
diff --git a/src/ast.zig b/src/ast.zig
index 8dbe32d..73b77cf 100644
--- a/src/ast.zig
+++ b/src/ast.zig
@@ -125,6 +125,13 @@ pub const Stmt = union(enum) {
     If: IfStmt,
     Loop: LoopStmt,
 
+    Return: ReturnStmt,
+
+    pub const ReturnStmt = struct {
+        keyword: Token,
+        value: *Expr,
+    };
+
     pub fn mkPrintln(allocator: *std.mem.Allocator, expr: *Expr) !*Stmt {
         var stmt = try allocator.create(Stmt);
         stmt.* = Stmt{ .Println = expr };
@@ -164,6 +171,18 @@ pub const Stmt = union(enum) {
 
         return stmt;
     }
+
+    pub fn mkReturn(allocator: *std.mem.Allocator, tok: Token, value: *Expr) !*Stmt {
+        var stmt = try allocator.create(Stmt);
+        stmt.* = Stmt{
+            .Return = ReturnStmt{
+                .keyword = tok,
+                .value = value,
+            },
+        };
+
+        return stmt;
+    }
 };
 
 pub const Node = union(NodeType) {
@@ -361,6 +380,12 @@ pub fn printStmt(ident: usize, stmt: *Stmt) void {
             std.debug.warn(")\n");
         },
 
+        .Return => |ret| {
+            std.debug.warn("(return ");
+            printExpr(ret.value);
+            std.debug.warn(")\n");
+        },
+
         else => std.debug.warn("UnknownStmt-{}", @tagName(stmt.*)),
     }
 }
diff --git a/src/parser.zig b/src/parser.zig
index 40404dd..2a2bb7a 100644
--- a/src/parser.zig
+++ b/src/parser.zig
@@ -464,6 +464,7 @@ pub const Parser = struct {
             .If => try self.parseIfStmt(),
             .Loop => try self.parseLoop(),
             .Println => try self.parsePrintln(),
+            .Return => try self.parseReturn(),
 
             // TODO make newlines tokens and consume newline?
             else => try self.parseStmtExpr(),
@@ -525,14 +526,20 @@ pub const Parser = struct {
         return try Stmt.mkLoop(self.allocator, expr, body);
     }
 
+    fn parseReturn(self: *@This()) !*Stmt {
+        const tok = try self.consumeSingle(.Return);
+        const expr = (try self.parseExpr()).Expr;
+        return try Stmt.mkReturn(self.allocator, tok, expr);
+    }
+
     fn parsePrintln(self: *@This()) !*Stmt {
         _ = try self.consumeSingle(.Println);
 
         _ = try self.consumeSingle(.LeftParen);
-        var expr = try self.parseExpr();
+        var expr = (try self.parseExpr()).Expr;
         _ = try self.consumeSingle(.RightParen);
 
-        return try Stmt.mkPrintln(self.allocator, expr.Expr);
+        return try Stmt.mkPrintln(self.allocator, expr);
     }
 
     fn parseStmtExpr(self: *@This()) !*Stmt {