diff --git a/examples/hello.ry b/examples/hello.ry
index 62bfab3..40e69a4 100644
--- a/examples/hello.ry
+++ b/examples/hello.ry
@@ -30,5 +30,5 @@ fn add(a: i32, b: i32) i32 {
 }
 
 fn main() i32 {
-    return 1;
+    return 123;
 }
diff --git a/src/analysis.zig b/src/analysis.zig
index c3363a5..bc35d32 100644
--- a/src/analysis.zig
+++ b/src/analysis.zig
@@ -25,7 +25,7 @@ pub const Analyzer = struct {
         };
     }
 
-    fn setErrContext(self: *@This(), comptime fmt: ?[]const u8, args: ...) void {
+    fn setErrContext(self: *@This(), comptime fmt: ?[]const u8, args: var) void {
         if (fmt == null) {
             self.err_ctx = null;
             return;
@@ -42,21 +42,21 @@ pub const Analyzer = struct {
         self.err_tok = tok;
     }
 
-    fn doError(self: *@This(), comptime fmt: []const u8, args: ...) void {
+    fn doError(self: *@This(), comptime fmt: []const u8, args: var) void {
         self.hadError = true;
 
-        std.debug.warn("analysis error");
+        std.debug.warn("analysis error", .{});
         if (self.err_tok) |tok| {
-            std.debug.warn(" at line {}", tok.line);
+            std.debug.warn(" at line {}", .{tok.line});
         }
 
         if (self.err_ctx) |ctx| {
-            std.debug.warn(" on {}", ctx);
+            std.debug.warn(" on {}", .{ctx});
         }
 
-        std.debug.warn("\n\t");
+        std.debug.warn("\n\t", .{});
         std.debug.warn(fmt, args);
-        std.debug.warn("\n");
+        std.debug.warn("\n", .{});
     }
 
     /// Resolve a type in global scope
@@ -76,7 +76,7 @@ pub const Analyzer = struct {
                 var sym = ctx.symbol_table.get(val);
 
                 if (sym == null) {
-                    self.doError("Unknown type: '{}'", val);
+                    self.doError("Unknown type: '{}'", .{val});
                     return null;
                 }
 
@@ -85,11 +85,10 @@ pub const Analyzer = struct {
                     .Enum => SymbolUnderlyingType{ .Enum = val },
 
                     else => blk: {
-                        self.doError(
-                            "expected struct or enum for '{}', got {}",
+                        self.doError("expected struct or enum for '{}', got {}", .{
                             val,
                             @tagName(@as(comp.SymbolType, sym.?.value.*)),
-                        );
+                        });
                         break :blk null;
                     },
                 };
@@ -108,7 +107,7 @@ pub const Analyzer = struct {
     ) !void {
         var actual_enum = @as(comp.SymbolUnderlyingTypeEnum, symbol_type);
         if (actual_enum != wanted_type_enum) {
-            std.debug.warn("Expected {}, got {}\n", wanted_type_enum, actual_enum);
+            std.debug.warn("Expected {}, got {}\n", .{ wanted_type_enum, actual_enum });
             return CompileError.TypeError;
         }
     }
@@ -122,7 +121,7 @@ pub const Analyzer = struct {
             .Integer32, .Integer64, .Double => {},
             else => {
                 var actual_enum = @as(comp.SymbolUnderlyingTypeEnum, symbol_type);
-                std.debug.warn("Expected numeric, got {}\n", actual_enum);
+                std.debug.warn("Expected numeric, got {}\n", .{actual_enum});
                 return CompileError.TypeError;
             },
         }
@@ -136,12 +135,11 @@ pub const Analyzer = struct {
         expected_ident: []const u8,
     ) !void {
         if (!std.mem.eql(u8, sym_ident, expected_ident)) {
-            self.doError(
-                "Expected {} {}, got {}",
+            self.doError("Expected {} {}, got {}", .{
                 @tagName(typ_enum),
                 expected_ident,
                 sym_ident,
-            );
+            });
 
             return CompileError.TypeError;
         }
@@ -158,7 +156,7 @@ pub const Analyzer = struct {
         const expected_enum = @as(comp.SymbolUnderlyingTypeEnum, expected_type);
 
         if (symbol_enum != expected_enum) {
-            std.debug.warn("Expected {}, got {}\n", expected_enum, symbol_enum);
+            std.debug.warn("Expected {}, got {}\n", .{ expected_enum, symbol_enum });
             return CompileError.TypeError;
         }
 
@@ -244,7 +242,7 @@ pub const Analyzer = struct {
                 const name = struc.name.lexeme;
                 var typ = self.resolveGlobalType(ctx, name);
                 if (typ == null) {
-                    self.doError("Unknown struct name '{}'\n", name);
+                    self.doError("Unknown struct name '{}'\n", .{name});
                     return CompileError.TypeError;
                 }
 
@@ -267,12 +265,11 @@ pub const Analyzer = struct {
                         const param_type_val = @as(comp.SymbolUnderlyingTypeEnum, param_type);
                         const arg_type_val = @as(comp.SymbolUnderlyingTypeEnum, arg_type);
 
-                        self.doError(
-                            "Expected parameter {} to be {}, got {}",
+                        self.doError("Expected parameter {} to be {}, got {}", .{
                             idx,
                             @tagName(param_type_val),
                             @tagName(arg_type_val),
-                        );
+                        });
 
                         return CompileError.TypeError;
                     };
@@ -292,7 +289,7 @@ pub const Analyzer = struct {
                 var target = get.target.*;
                 const target_type = @as(ast.ExprType, target);
                 if (target_type != .Variable) {
-                    std.debug.warn("Expected Variable as get target, got {}\n", target_type);
+                    std.debug.warn("Expected Variable as get target, got {}\n", .{target_type});
                     return CompileError.TypeError;
                 }
 
@@ -322,11 +319,10 @@ pub const Analyzer = struct {
 
                         var kv = map.get(name);
                         if (kv == null) {
-                            self.doError(
-                                "Field {} not found in enum {}",
+                            self.doError("Field {} not found in enum {}", .{
                                 name,
                                 lexeme,
-                            );
+                            });
                             return CompileError.TypeError;
                         }
 
@@ -334,10 +330,9 @@ pub const Analyzer = struct {
                     },
 
                     else => {
-                        self.doError(
-                            "Expected Struct/Enum as get target, got {}",
+                        self.doError("Expected Struct/Enum as get target, got {}", .{
                             @as(comp.SymbolUnderlyingTypeEnum, global_typ),
-                        );
+                        });
 
                         return CompileError.TypeError;
                     },
@@ -346,7 +341,7 @@ pub const Analyzer = struct {
 
             .Assign => |assign| {
                 if (ctx.current_scope == null) {
-                    self.doError("Can't assign without a scope");
+                    self.doError("Can't assign without a scope", .{});
                     return CompileError.Invalid;
                 }
 
@@ -355,7 +350,7 @@ pub const Analyzer = struct {
                 );
 
                 if (var_type == null) {
-                    self.doError("Assign target variable not found");
+                    self.doError("Assign target variable not found", .{});
                     return CompileError.Invalid;
                 }
 
@@ -393,7 +388,7 @@ pub const Analyzer = struct {
                 var var_type = try self.resolveExprType(ctx, vardecl.value);
 
                 if (ctx.current_scope == null) {
-                    self.doError("Can't declare without a scope");
+                    self.doError("Can't declare without a scope", .{});
                     return CompileError.Invalid;
                 }
 
@@ -462,7 +457,7 @@ pub const Analyzer = struct {
         node: *ast.Node,
     ) !void {
         self.setErrToken(null);
-        self.setErrContext(null);
+        self.setErrContext(null, .{});
 
         // always reset the contexts' current function
         ctx.cur_function = null;
@@ -472,10 +467,13 @@ pub const Analyzer = struct {
             .FnDecl => |decl| {
                 self.setErrToken(decl.return_type);
                 const name = decl.func_name.lexeme;
-                self.setErrContext("function {}", name);
+                self.setErrContext("function {}", .{name});
                 var ret_type = self.resolveGlobalType(ctx, decl.return_type.lexeme);
 
-                std.debug.warn("start analysis of fn {}, ret type: {}\n", decl.func_name.lexeme, ret_type);
+                std.debug.warn("start analysis of fn {}, ret type: {}\n", .{
+                    decl.func_name.lexeme,
+                    ret_type,
+                });
 
                 var parameters = comp.TypeList.init(self.allocator);
                 for (decl.params.toSlice()) |param| {
@@ -496,10 +494,10 @@ pub const Analyzer = struct {
                     try ctx.insertFn(decl, ret_type.?, parameters, scope);
                 } else {
                     if (ret_type != null)
-                        self.doError("Return type was not fully resolved");
+                        self.doError("Return type was not fully resolved", .{});
 
                     if (parameters.len != decl.params.len)
-                        self.doError("Fully analyzed {} parameters, wanted {}", parameters.len, decl.params.len);
+                        self.doError("Fully analyzed {} parameters, wanted {}", .{ parameters.len, decl.params.len });
 
                     return CompileError.TypeError;
                 }
@@ -520,7 +518,7 @@ pub const Analyzer = struct {
 
             .Struct => |struc| {
                 self.setErrToken(struc.name);
-                self.setErrContext("struct {}", struc.name.lexeme);
+                self.setErrContext("struct {}", .{struc.name.lexeme});
 
                 var types = comp.TypeList.init(self.allocator);
 
@@ -543,7 +541,7 @@ pub const Analyzer = struct {
             // TODO change enums to u32
             .Enum => |enu| {
                 self.setErrToken(enu.name);
-                self.setErrContext("enum {}", enu.name.lexeme);
+                self.setErrContext("enum {}", .{enu.name.lexeme});
 
                 try ctx.insertEnum(enu);
             },
@@ -551,7 +549,7 @@ pub const Analyzer = struct {
             .ConstDecl => |constlist| {
                 for (constlist.toSlice()) |constdecl| {
                     self.setErrToken(constdecl.name);
-                    self.setErrContext("const {}", constdecl.name.lexeme);
+                    self.setErrContext("const {}", .{constdecl.name.lexeme});
 
                     var expr_type = try self.resolveExprType(ctx, constdecl.expr);
                     try ctx.insertConst(constdecl, expr_type);
@@ -559,7 +557,7 @@ pub const Analyzer = struct {
             },
 
             .Block => {
-                self.doError("Block can't be found at root");
+                self.doError("Block can't be found at root", .{});
                 return CompileError.Invalid;
             },
         }
diff --git a/src/ast_printer.zig b/src/ast_printer.zig
index 36bd72a..328f880 100644
--- a/src/ast_printer.zig
+++ b/src/ast_printer.zig
@@ -10,28 +10,28 @@ const warn = std.debug.warn;
 fn printIdent(ident: usize) void {
     var i: usize = 0;
     while (i < ident) : (i += 1) {
-        std.debug.warn("\t");
+        std.debug.warn("\t", .{});
     }
 }
 
-fn print(ident: usize, comptime fmt: []const u8, args: ...) void {
+fn print(ident: usize, comptime fmt: []const u8, args: var) void {
     printIdent(ident);
     std.debug.warn(fmt, args);
 }
 
 fn printBlock(ident: usize, block: var, endNewline: bool) void {
-    std.debug.warn("(\n");
+    std.debug.warn("(\n", .{});
 
     for (block.toSlice()) |stmt| {
         printIdent(ident);
         printStmt(ident, &stmt);
-        std.debug.warn("\n");
+        std.debug.warn("\n", .{});
     }
 
     if (endNewline) {
-        print(ident - 1, ")\n");
+        print(ident - 1, ")\n", .{});
     } else {
-        print(ident - 1, ")");
+        print(ident - 1, ")", .{});
     }
 }
 
@@ -48,49 +48,45 @@ pub fn printNode(node: *const Node, ident: usize) void {
                 const vari = method.variable.lexeme;
                 const typ = method.typ.lexeme;
 
-                warn("(method {} {} {} {} (", vari, typ, name, ret_type);
+                warn("(method {} {} {} {} (", .{ vari, typ, name, ret_type });
             } else {
-                warn("(fn {} {} (", name, ret_type);
+                warn("(fn {} {} (", .{ name, ret_type });
             }
 
             for (decl.params.toSlice()) |param| {
-                warn(" ({} {})", param.name.lexeme, param.typ.lexeme);
+                warn(" ({} {})", .{ param.name.lexeme, param.typ.lexeme });
             }
-            warn(") ");
+            warn(") ", .{});
 
             printBlock(ident + 1, decl.body, false);
-            warn("\n");
+            warn("\n", .{});
         },
 
         .ConstDecl => |consts| {
-            print(ident, "(const (\n");
+            print(ident, "(const (\n", .{});
 
             for (consts.toSlice()) |const_decl| {
-                print(
-                    ident + 1,
-                    "({} ",
+                print(ident + 1, "({} ", .{
                     const_decl.name.lexeme,
-                );
+                });
 
                 printExpr(const_decl.expr);
-                std.debug.warn(")\n");
+                std.debug.warn(")\n", .{});
             }
 
-            print(ident, "))\n");
+            print(ident, "))\n", .{});
         },
 
         .Enum => |decl| {
-            print(ident, "(enum {} (\n", decl.name.lexeme);
+            print(ident, "(enum {} (\n", .{decl.name.lexeme});
 
             for (decl.fields.toSlice()) |field| {
-                print(
-                    ident + 1,
-                    "{}\n",
+                print(ident + 1, "{}\n", .{
                     field.lexeme,
-                );
+                });
             }
 
-            print(ident, "))\n");
+            print(ident, "))\n", .{});
         },
 
         .Root => {
@@ -100,34 +96,34 @@ pub fn printNode(node: *const Node, ident: usize) void {
         },
 
         .Struct => |struc| {
-            print(ident, "(struct {} (\n", struc.name.lexeme);
+            print(ident, "(struct {} (\n", .{struc.name.lexeme});
             for (struc.fields.toSlice()) |field| {
-                print(ident + 1, "({} {})\n", field.name.lexeme, field.typ.lexeme);
+                print(ident + 1, "({} {})\n", .{ field.name.lexeme, field.typ.lexeme });
             }
-            print(ident, "))\n");
+            print(ident, "))\n", .{});
         },
 
         else => {
-            print(ident, "unknown node: {}\n", node);
+            print(ident, "unknown node: {}\n", .{node});
         },
     }
 }
 
 fn parenthetize(name: []const u8, exprs: []const Expr) void {
-    std.debug.warn("({}", name);
+    std.debug.warn("({}", .{name});
 
     for (exprs) |expr| {
-        std.debug.warn(" ");
+        std.debug.warn(" ", .{});
         printExpr(&expr);
     }
 
-    std.debug.warn(")");
+    std.debug.warn(")", .{});
 }
 
 fn printTwoExprs(expr_a: *const Expr, expr_b: *const Expr) void {
-    std.debug.warn(" ");
+    std.debug.warn(" ", .{});
     printExpr(expr_a);
-    std.debug.warn(" ");
+    std.debug.warn(" ", .{});
     printExpr(expr_b);
 }
 
@@ -161,9 +157,9 @@ fn binOpToStr(op: BinaryOperator) ?[]const u8 {
 }
 
 fn printBinOp(inner: var) void {
-    std.debug.warn("({}", binOpToStr(inner.op));
+    std.debug.warn("({}", .{binOpToStr(inner.op)});
     printTwoExprs(inner.left, inner.right);
-    std.debug.warn(")");
+    std.debug.warn(")", .{});
 }
 
 const unary_operator_tokens = [_][]const u8{
@@ -187,9 +183,9 @@ fn printSingleOp(op: UnaryOperator, applied: *const Expr) void {
 }
 
 fn printSimpleOp(op: ?[]const u8, applied: *const Expr) void {
-    std.debug.warn("({}", op);
+    std.debug.warn("({}", .{op});
     printExpr(applied);
-    std.debug.warn(")");
+    std.debug.warn(")", .{});
 }
 
 pub fn printExpr(expr: *const Expr) void {
@@ -201,66 +197,66 @@ pub fn printExpr(expr: *const Expr) void {
 
         .Literal => |literal| {
             switch (literal) {
-                .Bool => |val| std.debug.warn("{}", val),
-                .Integer32 => |val| std.debug.warn("{}", val),
-                .Integer64 => |val| std.debug.warn("{}", val),
-                .Float => |val| std.debug.warn("{}", val),
-                .String => |val| std.debug.warn("'{}'", val),
+                .Bool => |val| std.debug.warn("{}", .{val}),
+                .Integer32 => |val| std.debug.warn("{}", .{val}),
+                .Integer64 => |val| std.debug.warn("{}", .{val}),
+                .Float => |val| std.debug.warn("{}", .{val}),
+                .String => |val| std.debug.warn("'{}'", .{val}),
                 .Array => |exprs| {
                     parenthetize("array", exprs.toSlice());
                 },
-                else => |typ| std.debug.warn("UnknownLiteral-{}", typ),
+                else => |typ| std.debug.warn("UnknownLiteral-{}", .{typ}),
             }
         },
 
-        .Variable => |token| std.debug.warn("{}", token.lexeme),
+        .Variable => |token| std.debug.warn("{}", .{token.lexeme}),
 
         .Assign => |assign| {
-            std.debug.warn("(set ");
-            std.debug.warn("{} ", assign.name.lexeme);
+            std.debug.warn("(set ", .{});
+            std.debug.warn("{} ", .{assign.name.lexeme});
             printExpr(assign.value);
-            std.debug.warn(")");
+            std.debug.warn(")", .{});
         },
 
         .Call => |call| {
-            std.debug.warn("(");
+            std.debug.warn("(", .{});
             printExpr(call.callee);
 
             for (call.arguments.toSlice()) |arg| {
-                std.debug.warn(" ");
+                std.debug.warn(" ", .{});
                 printExpr(&arg);
             }
 
-            std.debug.warn(")");
+            std.debug.warn(")", .{});
         },
 
         .Struct => |val| {
-            std.debug.warn("({} (", val.name.lexeme);
+            std.debug.warn("({} (", .{val.name.lexeme});
 
             for (val.inits.toSlice()) |init| {
-                std.debug.warn(" ({} ", init.field.lexeme);
+                std.debug.warn(" ({} ", .{init.field.lexeme});
                 printExpr(init.expr);
-                std.debug.warn(")");
+                std.debug.warn(")", .{});
             }
 
-            std.debug.warn("))");
+            std.debug.warn("))", .{});
         },
 
         .Get => |get| {
-            warn("(");
+            warn("(", .{});
             printExpr(get.target);
-            warn(".{})", get.name.lexeme);
+            warn(".{})", .{get.name.lexeme});
         },
 
         .Set => |set| {
-            warn("(set ");
+            warn("(set ", .{});
             printExpr(set.struc);
-            warn(" {} ", set.field.lexeme);
+            warn(" {} ", .{set.field.lexeme});
             printExpr(set.value);
-            warn(")");
+            warn(")", .{});
         },
 
-        else => std.debug.warn("UnknownExpr-{}", @tagName(expr.*)),
+        else => std.debug.warn("UnknownExpr-{}", .{@tagName(expr.*)}),
     }
 }
 
@@ -270,67 +266,67 @@ pub fn printStmt(ident: usize, stmt: *const Stmt) void {
         .Expr => |expr| printExpr(expr),
 
         .VarDecl => |decl| {
-            std.debug.warn("(let {} ", decl.name.lexeme);
+            std.debug.warn("(let {} ", .{decl.name.lexeme});
             printExpr(decl.value);
-            std.debug.warn(")");
+            std.debug.warn(")", .{});
         },
 
         .If => |ifstmt| {
-            std.debug.warn("(if ");
+            std.debug.warn("(if ", .{});
             printExpr(ifstmt.condition);
-            std.debug.warn(" ");
+            std.debug.warn(" ", .{});
 
             printBlock(ident + 1, ifstmt.then_branch, false);
             if (ifstmt.else_branch) |else_branch| {
-                std.debug.warn(" else ");
+                std.debug.warn(" else ", .{});
                 printBlock(ident + 1, else_branch, false);
             }
 
-            std.debug.warn(")\n");
+            std.debug.warn(")\n", .{});
         },
 
         .Loop => |loop| {
-            std.debug.warn("(loop ");
+            std.debug.warn("(loop ", .{});
             if (loop.condition) |cond| {
                 printExpr(cond);
             } else {
-                std.debug.warn("true");
+                std.debug.warn("true", .{});
             }
-            std.debug.warn(" ");
+            std.debug.warn(" ", .{});
 
             printBlock(ident + 1, loop.then_branch, false);
-            std.debug.warn(")\n");
+            std.debug.warn(")\n", .{});
         },
 
         .For => |forstmt| {
-            std.debug.warn("(for ");
+            std.debug.warn("(for ", .{});
 
             if (forstmt.index) |index| {
-                std.debug.warn("({} {}) ", index.lexeme, forstmt.value.lexeme);
+                std.debug.warn("({} {}) ", .{ index.lexeme, forstmt.value.lexeme });
             } else {
-                std.debug.warn("{} ", forstmt.value.lexeme);
+                std.debug.warn("{} ", .{forstmt.value.lexeme});
             }
 
-            std.debug.warn("{} ", forstmt.array.lexeme);
+            std.debug.warn("{} ", .{forstmt.array.lexeme});
 
             printBlock(ident + 1, forstmt.block, false);
-            std.debug.warn(")\n");
+            std.debug.warn(")\n", .{});
         },
 
         .Return => |ret| {
-            std.debug.warn("(return ");
+            std.debug.warn("(return ", .{});
             printExpr(ret.value);
-            std.debug.warn(")\n");
+            std.debug.warn(")\n", .{});
         },
 
-        else => std.debug.warn("UnknownStmt-{}", @tagName(stmt.*)),
+        else => std.debug.warn("UnknownStmt-{}", .{@tagName(stmt.*)}),
     }
 }
 
 // very bad but be like that
 fn retWithName(prefix: []const u8, inner: []const u8) []const u8 {
-    var ret_nam_buf = std.heap.direct_allocator.alloc(u8, 256) catch unreachable;
-    return std.fmt.bufPrint(ret_nam_buf[0..], "{}({})", prefix, inner) catch unreachable;
+    var ret_nam_buf = std.heap.page_allocator.alloc(u8, 256) catch unreachable;
+    return std.fmt.bufPrint(ret_nam_buf[0..], "{}({})", .{ prefix, inner }) catch unreachable;
 }
 
 fn prettyType(typ: SymbolUnderlyingType) []const u8 {
@@ -347,11 +343,11 @@ fn prettyType(typ: SymbolUnderlyingType) []const u8 {
 }
 
 pub fn printScope(scope: *Scope, ident: usize) void {
-    print(ident, "scope '{}' at addr {}\n", scope.id, @ptrToInt(scope));
+    print(ident, "scope '{}' at addr {}\n", .{ scope.id, @ptrToInt(scope) });
 
     var it = scope.env.iterator();
     while (it.next()) |kv| {
-        print(ident + 1, "sym: {}, typ: {}\n", kv.key, prettyType(kv.value));
+        print(ident + 1, "sym: {}, typ: {}\n", .{ kv.key, prettyType(kv.value) });
     }
 
     for (scope.children.toSlice()) |child| {
@@ -365,60 +361,56 @@ pub fn printContext(ctx: CompilationContext) void {
     while (it.next()) |kv| {
         switch (kv.value.*) {
             .Function => |fn_sym| {
-                std.debug.warn(
-                    "function {} returns {}\n",
+                std.debug.warn("function {} returns {}\n", .{
                     kv.key,
                     prettyType(fn_sym.return_type),
-                );
+                });
 
                 for (fn_sym.decl.params.toSlice()) |param| {
                     var param_kv = fn_sym.parameters.get(param.name.lexeme).?;
-                    std.debug.warn(
-                        "\tparameter {} typ {}\n",
+                    std.debug.warn("\tparameter {} typ {}\n", .{
                         param_kv.key,
                         prettyType(param_kv.value.typ),
-                    );
+                    });
                 }
 
                 // go through scopes
-                std.debug.warn("scope info:\n");
+                std.debug.warn("scope info:\n", .{});
                 printScope(fn_sym.scope, 1);
             },
 
             .Struct => |typemap| {
-                std.debug.warn("struct '{}'\n", kv.key);
+                std.debug.warn("struct '{}'\n", .{kv.key});
                 var map_it = typemap.iterator();
                 while (map_it.next()) |map_kv| {
-                    std.debug.warn(
-                        "\tfield {} type {}\n",
+                    std.debug.warn("\tfield {} type {}\n", .{
                         map_kv.key,
                         prettyType(map_kv.value),
-                    );
+                    });
                 }
             },
 
-            .Variable => std.debug.warn(
-                "variable {} type {}\n",
+            .Variable => std.debug.warn("variable {} type {}\n", .{
                 kv.key,
                 kv.value,
-            ),
+            }),
 
             .Enum => |identmap| {
-                std.debug.warn("enum {}:", kv.key);
+                std.debug.warn("enum {}:", .{kv.key});
 
                 var mapit = identmap.iterator();
 
                 while (mapit.next()) |field_kv| {
-                    std.debug.warn("\t{} => {}\n", field_kv.key, field_kv.value);
+                    std.debug.warn("\t{} => {}\n", .{ field_kv.key, field_kv.value });
                 }
             },
 
             .Const => |typ| {
-                std.debug.warn("const '{}', typ={}\n", kv.key, prettyType(typ));
+                std.debug.warn("const '{}', typ={}\n", .{ kv.key, prettyType(typ) });
             },
 
             else => {
-                std.debug.warn("TODO handle print of {}\n", kv.value);
+                std.debug.warn("TODO handle print of {}\n", .{kv.value});
                 unreachable;
             },
         }
diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 6da6f82..ff2d6f6 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -4,9 +4,8 @@ const llvm = @import("../llvm.zig");
 const comp = @import("../comp_ctx.zig");
 const CompileError = @import("../codegen.zig").CompileError;
 
-fn sliceify(non_slice: ?[*]const u8) []const u8 {
-    if (non_slice == null) return "";
-    return non_slice.?[0..std.mem.len(u8, non_slice.?)];
+fn sliceify(non_slice: ?[*:0]const u8) []const u8 {
+    return non_slice.?[0..std.mem.len(non_slice.?)];
 }
 
 fn mkLLVMBool(val: bool) llvm.LLVMValueRef {
@@ -42,7 +41,7 @@ pub const Codegen = struct {
             .Bool => llvm.LLVMInt1Type(),
 
             .OpaqueType => |val| {
-                std.debug.warn("Invalid return type: {}\n", val);
+                std.debug.warn("Invalid return type: {}\n", .{val});
                 return CompileError.TypeError;
             },
 
@@ -52,14 +51,14 @@ pub const Codegen = struct {
                     .Struct => unreachable,
                     .Enum => llvm.LLVMInt32Type(),
                     else => {
-                        std.debug.warn("Function {} is not a type\n", lex);
+                        std.debug.warn("Function {} is not a type\n", .{lex});
                         return CompileError.TypeError;
                     },
                 };
             },
 
             else => {
-                std.debug.warn("TODO handle {}\n", typ);
+                std.debug.warn("TODO handle {}\n", .{typ});
                 return CompileError.TypeError;
             },
         };
@@ -72,18 +71,17 @@ pub const Codegen = struct {
             .Enum => |map| {
                 var val = map.get(get.name.lexeme);
                 if (val == null) {
-                    std.debug.warn(
-                        "enum {} does not have field {}\n",
+                    std.debug.warn("enum {} does not have field {}\n", .{
                         vari.lexeme,
                         get.name.lexeme,
-                    );
+                    });
                 }
                 return llvm.LLVMConstInt(llvm.LLVMInt32Type(), val.?.value, 1);
             },
 
             .Struct => @panic("TODO handle struct"),
             else => {
-                std.debug.warn("Invalid get target: {}\n", @as(comp.SymbolType, sym.*));
+                std.debug.warn("Invalid get target: {}\n", .{@as(comp.SymbolType, sym.*)});
                 return CompileError.EmitError;
             },
         }
@@ -126,8 +124,8 @@ pub const Codegen = struct {
                 var right = try self.emitExpr(builder, unary.right);
 
                 return switch (unary.op) {
-                    .Negate => llvm.LLVMBuildNeg(builder, right, c"neg_tmp"),
-                    .Not => llvm.LLVMBuildNot(builder, right, c"neg_tmp"),
+                    .Negate => llvm.LLVMBuildNeg(builder, right, "neg_tmp"),
+                    .Not => llvm.LLVMBuildNot(builder, right, "neg_tmp"),
                 };
             },
 
@@ -136,16 +134,16 @@ pub const Codegen = struct {
                 var right = try self.emitExpr(builder, binary.right);
 
                 return switch (binary.op) {
-                    .Add => llvm.LLVMBuildAdd(builder, left, right, c"addtmp"),
-                    .Sub => llvm.LLVMBuildSub(builder, left, right, c"subtmp"),
-                    .Mul => llvm.LLVMBuildMul(builder, left, right, c"multmp"),
+                    .Add => llvm.LLVMBuildAdd(builder, left, right, "addtmp"),
+                    .Sub => llvm.LLVMBuildSub(builder, left, right, "subtmp"),
+                    .Mul => llvm.LLVMBuildMul(builder, left, right, "multmp"),
 
-                    //.Div => llvm.LLVMBuildDiv(builder, left, right, c"divtmp"),
-                    .And => llvm.LLVMBuildAnd(builder, left, right, c"andtmp"),
-                    .Or => llvm.LLVMBuildOr(builder, left, right, c"ortmp"),
+                    //.Div => llvm.LLVMBuildDiv(builder, left, right, "divtmp"),
+                    .And => llvm.LLVMBuildAnd(builder, left, right, "andtmp"),
+                    .Or => llvm.LLVMBuildOr(builder, left, right, "ortmp"),
 
                     else => {
-                        std.debug.warn("Unexpected binary operator: '{}'\n", binary.op);
+                        std.debug.warn("Unexpected binary operator: '{}'\n", .{binary.op});
                         return CompileError.EmitError;
                     },
                 };
@@ -169,7 +167,7 @@ pub const Codegen = struct {
                     },
 
                     else => {
-                        std.debug.warn("Invalid get target: {}\n", @as(ast.ExprType, target));
+                        std.debug.warn("Invalid get target: {}\n", .{@as(ast.ExprType, target)});
                         return CompileError.EmitError;
                     },
                 }
@@ -180,7 +178,7 @@ pub const Codegen = struct {
 
                 var llvm_func = self.llvm_table.get(name);
                 if (llvm_func == null) {
-                    std.debug.warn("Function '{}' not found\n", name);
+                    std.debug.warn("Function '{}' not found\n", .{name});
                     return CompileError.EmitError;
                 }
 
@@ -199,7 +197,7 @@ pub const Codegen = struct {
                     llvm_func.?.value,
                     args_slice.ptr,
                     @intCast(c_uint, args_slice.len),
-                    c"call",
+                    "call",
                 );
             },
 
@@ -219,7 +217,7 @@ pub const Codegen = struct {
                 var kv_opt = self.ctx.current_scope.?.meta_map.get(vari.lexeme);
 
                 if (kv_opt == null) {
-                    std.debug.warn("variable {} not fully analyzed\n", vari.lexeme);
+                    std.debug.warn("variable {} not fully analyzed\n", .{vari.lexeme});
                     return CompileError.EmitError;
                 }
 
@@ -227,12 +225,12 @@ pub const Codegen = struct {
                 // is coming from the scope or from the function
 
                 var metadata = kv_opt.?.value;
-                std.debug.warn("!! LOAD FROM VAR META {}\n", @ptrToInt(metadata));
+                std.debug.warn("!! LOAD FROM VAR META {}\n", .{@ptrToInt(metadata)});
 
                 var buf = try self.allocator.alloc(u8, 512);
                 errdefer self.allocator.free(buf);
 
-                var load_str = try std.fmt.bufPrint(buf, "{}_loaded", vari.lexeme);
+                var load_str = try std.fmt.bufPrint(buf, "{}_loaded", .{vari.lexeme});
 
                 var load_cstr = try std.cstr.addNullByte(self.allocator, load_str);
                 errdefer self.allocator.free(load_cstr);
@@ -256,14 +254,14 @@ pub const Codegen = struct {
             },
 
             else => {
-                std.debug.warn("Got unexpected expr {}\n", @as(ast.ExprType, expr.*));
+                std.debug.warn("Got unexpected expr {}\n", .{@as(ast.ExprType, expr.*)});
                 return CompileError.EmitError;
             },
         };
     }
 
     fn emitStmt(self: *Codegen, builder: var, stmt: *ast.Stmt) anyerror!void {
-        std.debug.warn("cgen: emitting stmt {}\n", @as(ast.StmtType, stmt.*));
+        std.debug.warn("cgen: emitting stmt {}\n", .{@as(ast.StmtType, stmt.*)});
 
         switch (stmt.*) {
             .Expr => |expr| _ = try self.emitExpr(builder, expr),
@@ -276,14 +274,14 @@ pub const Codegen = struct {
             .If => |ifstmt| {
                 var cond = try self.emitExpr(builder, ifstmt.condition);
                 var zero = mkLLVMBool(false);
-                var icmp = llvm.LLVMBuildICmp(builder, llvm.LLVMIntPredicate.LLVMIntNE, cond, zero, c"ifcond");
+                var icmp = llvm.LLVMBuildICmp(builder, llvm.LLVMIntPredicate.LLVMIntNE, cond, zero, "ifcond");
 
                 var insert = llvm.LLVMGetInsertBlock(builder);
                 var function = llvm.LLVMGetBasicBlockParent(insert);
 
-                var then_bb = llvm.LLVMAppendBasicBlock(function, c"then");
-                var else_bb = llvm.LLVMAppendBasicBlock(function, c"else");
-                var merge_bb = llvm.LLVMAppendBasicBlock(function, c"ifcont");
+                var then_bb = llvm.LLVMAppendBasicBlock(function, "then");
+                var else_bb = llvm.LLVMAppendBasicBlock(function, "else");
+                var merge_bb = llvm.LLVMAppendBasicBlock(function, "ifcont");
 
                 var condbr = llvm.LLVMBuildCondBr(builder, icmp, then_bb, else_bb);
 
@@ -380,14 +378,14 @@ pub const Codegen = struct {
 
                 var_metadata.*.llvm_alloca = variable;
 
-                std.debug.warn("!! DECL VAR {} => {}\n", @ptrToInt(var_metadata), variable);
+                std.debug.warn("!! DECL VAR {} => {}\n", .{ @ptrToInt(var_metadata), variable });
 
                 var llvm_expr = try self.emitExpr(builder, vardecl.value);
                 _ = llvm.LLVMBuildStore(builder, llvm_expr, variable);
             },
 
             else => {
-                std.debug.warn("Got unexpected stmt {}\n", stmt.*);
+                std.debug.warn("Got unexpected stmt {}\n", .{stmt.*});
                 return CompileError.EmitError;
             },
         }
@@ -410,7 +408,7 @@ pub const Codegen = struct {
             .FnDecl => |decl| {
                 const name = decl.func_name.lexeme;
                 self.current_function_name = name;
-                std.debug.warn("cgen: genning function '{}'\n", name);
+                std.debug.warn("cgen: genning function '{}'\n", .{name});
 
                 var fn_sym = self.getFnSymbol(name);
 
@@ -437,7 +435,7 @@ pub const Codegen = struct {
                 _ = try self.llvm_table.put(name, func);
 
                 var buf = try self.allocator.alloc(u8, 512);
-                var entry_lbl = try std.fmt.bufPrint(buf, "fn_{}_entry", name);
+                var entry_lbl = try std.fmt.bufPrint(buf, "fn_{}_entry", .{name});
                 var entry_lbl_cstr = try std.cstr.addNullByte(self.allocator, entry_lbl);
                 var entry = llvm.LLVMAppendBasicBlock(func, entry_lbl_cstr.ptr);
 
@@ -455,7 +453,7 @@ pub const Codegen = struct {
 
                     var alloca = llvm.LLVMBuildAlloca(builder, try self.typeToLLVM(param.typ), param_name_cstr.ptr);
 
-                    std.debug.warn("SET PARAM LLVM ALLOCA {} to {}\n", param_node.name.lexeme, alloca);
+                    std.debug.warn("SET PARAM LLVM ALLOCA {} to {}\n", .{ param_node.name.lexeme, alloca });
                     param.llvm_alloca = alloca;
 
                     _ = llvm.LLVMBuildStore(
@@ -475,7 +473,7 @@ pub const Codegen = struct {
                 }
 
                 self.ctx.dumpScope();
-                std.debug.warn("cgen: generated function '{}'\n", name);
+                std.debug.warn("cgen: generated function '{}'\n", .{name});
             },
 
             // NOTE: enums don't have specific llvm ir code generated for them
@@ -504,17 +502,17 @@ pub const Codegen = struct {
             },
 
             else => {
-                std.debug.warn("TODO handle node type {}\n", @tagName(node.*));
+                std.debug.warn("TODO handle node type {}\n", .{@tagName(node.*)});
                 return;
             },
         }
     }
 
     pub fn gen(self: *Codegen, root: *ast.Node) !void {
-        std.debug.warn("cgen: start gen\n");
+        std.debug.warn("cgen: start gen\n", .{});
         _ = llvm.LLVMInitializeNativeTarget();
 
-        var mod = llvm.LLVMModuleCreateWithName(c"awoo").?;
+        var mod = llvm.LLVMModuleCreateWithName("awoo").?;
         defer llvm.LLVMDisposeModule(mod);
 
         var root_slice = root.Root.toSlice();
@@ -522,20 +520,20 @@ pub const Codegen = struct {
             try self.genNode(mod, &root_slice[idx]);
         }
 
-        var err: ?[*]u8 = null;
+        var err: ?[*:0]u8 = null;
         defer llvm.LLVMDisposeMessage(err);
 
-        if (llvm.LLVMPrintModuleToFile(mod, c"output.ll", &err) != 0) {
-            std.debug.warn("error printing module to file: {}\n", sliceify(err));
+        if (llvm.LLVMPrintModuleToFile(mod, "output.ll", &err) != 0) {
+            std.debug.warn("error printing module to file: {}\n", .{sliceify(err)});
             return CompileError.BackendError;
         }
 
-        //if (llvm.LLVMWriteBitcodeToFile(mod, c"awoo.bc") != 0) {
-        //    std.debug.warn("error writing bitcode to file: {}\n", sliceify(err));
+        //if (llvm.LLVMWriteBitcodeToFile(mod, "awoo.bc") != 0) {
+        //    std.debug.warn("error writing bitcode to file: {}\n" , .{  sliceify(err) });
         //    return CompileError.BackendError;
         //}
 
-        std.debug.warn("cgen: verify llvm module\n");
+        std.debug.warn("cgen: verify llvm module\n", .{});
         _ = llvm.LLVMVerifyModule(
             mod,
             llvm.LLVMVerifierFailureAction.LLVMAbortProcessAction,
@@ -550,7 +548,7 @@ pub const Codegen = struct {
 
         var engine: llvm.LLVMExecutionEngineRef = undefined;
         if (llvm.LLVMCreateExecutionEngineForModule(&engine, mod, &err) != 0) {
-            std.debug.warn("failed to create execution engine: {}\n", sliceify(err));
+            std.debug.warn("failed to create execution engine: {}\n", .{sliceify(err)});
             return CompileError.BackendError;
         }
 
@@ -570,9 +568,9 @@ pub const Codegen = struct {
         var features = llvm.LLVMGetTargetMachineFeatureString(machine);
         var triple = llvm.LLVMGetTargetMachineTriple(machine);
 
-        std.debug.warn("target: {}\n", sliceify(desc));
-        std.debug.warn("triple: {}\n", sliceify(triple));
-        std.debug.warn("features: {}\n", sliceify(features));
+        std.debug.warn("target: {}\n", .{sliceify(desc)});
+        std.debug.warn("triple: {}\n", .{sliceify(triple)});
+        std.debug.warn("features: {}\n", .{sliceify(features)});
 
         //if (llvm.LLVMTargetMachineEmitToFile(
         //    machine,
@@ -581,7 +579,7 @@ pub const Codegen = struct {
         //    llvm.LLVMCodeGenFileType.LLVMAssemblyFile,
         //    &err,
         //) != 0) {
-        //    std.debug.warn("failed to emit to assembly file: {}\n", sliceify(err));
+        //    std.debug.warn("failed to emit to assembly file: {}\n" , .{  sliceify(err) });
         //    return CompileError.BackendError;
         //}
 
@@ -592,7 +590,7 @@ pub const Codegen = struct {
             llvm.LLVMCodeGenFileType.LLVMObjectFile,
             &err,
         ) != 0) {
-            std.debug.warn("failed to emit to file: {}\n", sliceify(err));
+            std.debug.warn("failed to emit to file: {}\n", .{sliceify(err)});
             return CompileError.BackendError;
         }
     }
diff --git a/src/comp_ctx.zig b/src/comp_ctx.zig
index fdbcaeb..44f377b 100644
--- a/src/comp_ctx.zig
+++ b/src/comp_ctx.zig
@@ -158,7 +158,7 @@ pub const VariableMetadata = struct {
         typ: SymbolUnderlyingType,
     ) !*VariableMetadata {
         var meta = try allocator.create(VariableMetadata);
-        std.debug.warn("VARMETA create from scope={}, meta={}\n", @ptrToInt(scope), @ptrToInt(meta));
+        std.debug.warn("VARMETA create from scope={}, meta={}\n", .{ @ptrToInt(scope), @ptrToInt(meta) });
         meta.* = VariableMetadata{ .typ = typ, .from_scope = scope, .using = .Scope };
         return meta;
     }
@@ -169,7 +169,7 @@ pub const VariableMetadata = struct {
         typ: SymbolUnderlyingType,
     ) !*VariableMetadata {
         var meta = try allocator.create(VariableMetadata);
-        std.debug.warn("VARMETA create from fndecl={}, meta={}\n", @ptrToInt(func), @ptrToInt(meta));
+        std.debug.warn("VARMETA create from fndecl={}, meta={}\n", .{ @ptrToInt(func), @ptrToInt(meta) });
         meta.* = VariableMetadata{ .typ = typ, .from_function = func, .using = .Function };
         return meta;
     }
@@ -204,7 +204,7 @@ pub const CompilationContext = struct {
             @panic("can't bump scope from null");
         }
 
-        std.debug.warn("==scope bump== '{}'\n", scope_id);
+        std.debug.warn("==scope bump== '{}'\n", .{scope_id});
 
         var child = try self.current_scope.?.createChild(scope_id);
         self.current_scope = child;
@@ -212,7 +212,7 @@ pub const CompilationContext = struct {
 
     /// Set a given scope as the current scope.
     pub fn setScope(self: *@This(), scope: *Scope) void {
-        std.debug.warn("==set== set scope to {}\n", scope.id);
+        std.debug.warn("==set== set scope to {}\n", .{scope.id});
         self.current_scope = scope;
     }
 
@@ -224,11 +224,10 @@ pub const CompilationContext = struct {
 
         const parent_id: ?[]const u8 = if (self.current_scope.?.parent == null) null else self.current_scope.?.parent.?.id;
 
-        std.debug.warn(
-            "==scope dump== {} to {}\n",
+        std.debug.warn("==scope dump== {} to {}\n", .{
             self.current_scope.?.id,
             parent_id,
-        );
+        });
 
         self.current_scope = self.current_scope.?.parent;
     }
@@ -349,7 +348,7 @@ pub const CompilationContext = struct {
     ) !*SymbolData {
         var sym_kv = self.symbol_table.get(identifier);
         if (sym_kv == null) {
-            std.debug.warn("Unknown {} '{}'\n", typ, identifier);
+            std.debug.warn("Unknown {} '{}'\n", .{ typ, identifier });
             return CompilationError.TypeError;
         }
 
@@ -357,7 +356,7 @@ pub const CompilationContext = struct {
 
         var sym_typ = @as(SymbolType, value.*);
         if (sym_typ != typ) {
-            std.debug.warn("Expected {}, got {}\n", sym_typ, typ);
+            std.debug.warn("Expected {}, got {}\n", .{ sym_typ, typ });
             return CompilationError.TypeError;
         }
 
@@ -417,7 +416,7 @@ pub const CompilationContext = struct {
             }
         }
 
-        std.debug.warn("Unknown name {}\n", name);
+        std.debug.warn("Unknown name {}\n", .{name});
         return CompilationError.UnknownName;
     }
 
diff --git a/src/errors.zig b/src/errors.zig
index 9043f2e..88c05f1 100644
--- a/src/errors.zig
+++ b/src/errors.zig
@@ -2,9 +2,9 @@ const std = @import("std");
 
 pub fn report(line: usize, where: []const u8, ctx_opt: ?[]const u8, message: []const u8) void {
     if (ctx_opt) |ctx| {
-        std.debug.warn("[line {}] Error{} on {}: {}", line, where, ctx, message);
+        std.debug.warn("[line {}] Error{} on {}: {}", .{ line, where, ctx, message });
     } else {
-        std.debug.warn("[line {}] Error{}: {}", line, where, message);
+        std.debug.warn("[line {}] Error{}: {}", .{ line, where, message });
     }
 }
 
@@ -12,13 +12,13 @@ pub fn reportN(line: usize, message: []const u8) void {
     report(line, "", message);
 }
 
-pub fn reportFmt(line: usize, ctx_opt: ?[]const u8, comptime fmt: []const u8, args: ...) void {
+pub fn reportFmt(line: usize, ctx_opt: ?[]const u8, comptime fmt: []const u8, args: var) void {
     if (ctx_opt) |ctx| {
-        std.debug.warn("[line {}] Error on {}", line, ctx);
+        std.debug.warn("[line {}] Error on {}", .{ line, ctx });
     } else {
-        std.debug.warn("[line {}] Error", line);
+        std.debug.warn("[line {}] Error", .{line});
     }
 
     std.debug.warn(fmt, args);
-    std.debug.warn("\n");
+    std.debug.warn("\n", .{});
 }
diff --git a/src/main.zig b/src/main.zig
index 4dc9918..ba5d105 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -19,11 +19,10 @@ pub fn run(allocator: *std.mem.Allocator, slice: []const u8) !Result {
     // do a full scan pass, then reset, then do it again (with parser)
     while (true) {
         var tok_opt = scan.nextToken() catch |err| {
-            std.debug.warn(
-                "error at '{}': {}\n",
+            std.debug.warn("error at '{}': {}\n", .{
                 scan.currentLexeme(),
                 err,
-            );
+            });
 
             return Result.TokenizeError;
         };
@@ -32,7 +31,7 @@ pub fn run(allocator: *std.mem.Allocator, slice: []const u8) !Result {
             if (tok.typ == .EOF) break;
 
             // TODO remove
-            std.debug.warn("{x}\n", tok);
+            std.debug.warn("{x}\n", .{tok});
         }
     }
 
@@ -47,20 +46,20 @@ pub fn run(allocator: *std.mem.Allocator, slice: []const u8) !Result {
 
     var root = root_opt.?;
 
-    std.debug.warn("parse tree\n");
+    std.debug.warn("parse tree\n", .{});
     printer.printNode(root, 0);
 
     var solver = try analysis.Analyzer.init(allocator);
     var ctx = try solver.pass(root);
 
-    std.debug.warn("symbol table\n");
+    std.debug.warn("symbol table\n", .{});
     printer.printContext(ctx);
 
     var cgen = codegen.llvm.Codegen.init(allocator, &ctx);
     try cgen.gen(root);
 
     var child = try std.ChildProcess.init(
-        [_][]const u8{ "gcc", "src/entry.c", "outpath.o", "-o", "a.out" },
+        &[_][]const u8{ "gcc", "src/entry.c", "outpath.o", "-o", "a.out" },
         allocator,
     );
     try child.spawn();
@@ -70,13 +69,13 @@ pub fn run(allocator: *std.mem.Allocator, slice: []const u8) !Result {
 }
 
 pub fn main() anyerror!void {
-    const allocator = std.heap.direct_allocator;
+    const allocator = std.heap.page_allocator;
     var args_it = std.process.args();
     _ = args_it.skip();
 
     const filepath = try (args_it.next(allocator) orelse @panic("expected file path"));
 
-    var file = try std.fs.File.openRead(filepath);
+    var file = try std.fs.cwd().openFile(filepath, .{});
     defer file.close();
 
     const total_bytes = try file.getEndPos();
@@ -94,7 +93,7 @@ pub fn main() anyerror!void {
         .ParseError,
         .CompileError,
         => {
-            std.debug.warn("error: {}\n", result);
+            std.debug.warn("error: {}\n", .{result});
             std.os.exit(1);
         },
     }
diff --git a/src/parsers.zig b/src/parsers.zig
index dbf3722..391b48e 100644
--- a/src/parsers.zig
+++ b/src/parsers.zig
@@ -94,7 +94,7 @@ pub const Parser = struct {
         self.tokens.deinit();
     }
 
-    fn setErrContext(self: *Parser, comptime fmt: ?[]const u8, args: ...) void {
+    fn setErrContext(self: *Parser, comptime fmt: ?[]const u8, args: var) void {
         if (fmt == null) {
             self.err_ctx = null;
             return;
@@ -104,18 +104,18 @@ pub const Parser = struct {
         self.err_ctx = std.fmt.bufPrint(buf, fmt.?, args) catch unreachable;
     }
 
-    fn doError(self: *Parser, comptime fmt: []const u8, args: ...) ParseError {
+    fn doError(self: *Parser, comptime fmt: []const u8, args: var) ParseError {
         self.hadError = true;
 
-        std.debug.warn("parser error at line {}", self.scanner.line);
+        std.debug.warn("parser error at line {}", .{self.scanner.line});
         if (self.err_ctx) |ctx| {
-            std.debug.warn(" on {}", ctx);
+            std.debug.warn(" on {}", .{ctx});
         }
 
-        std.debug.warn("\n\t");
+        std.debug.warn("\n\t", .{});
 
         std.debug.warn(fmt, args);
-        std.debug.warn("\n");
+        std.debug.warn("\n", .{});
 
         return ParseError.CompileError;
     }
@@ -146,11 +146,14 @@ pub const Parser = struct {
     }
 
     fn tokenError(self: *Parser, token: Token, msg: []const u8) ParseError {
-        std.debug.warn("ctx: '{}'\n", self.err_ctx);
+        std.debug.warn("ctx: '{}'\n", .{self.err_ctx});
         if (token.typ == .EOF) {
             ereport.report(token.line, " at end", self.err_ctx, msg);
         } else {
-            ereport.reportFmt(token.line, self.err_ctx, " at '{}': {}", token.lexeme, msg);
+            ereport.reportFmt(token.line, self.err_ctx, " at '{}': {}", .{
+                token.lexeme,
+                msg,
+            });
         }
 
         return ParseError.CompileError;
@@ -177,7 +180,7 @@ pub const Parser = struct {
         }
 
         try self.tokens.append(token);
-        std.debug.warn("skip to {}\n", token);
+        std.debug.warn("skip to {}\n", .{token});
         return token;
     }
 
@@ -203,12 +206,10 @@ pub const Parser = struct {
 
         // TODO maybe this could be entirely comptime?
         var buf_main: [1000]u8 = undefined;
-        var buf = try std.fmt.bufPrint(
-            buf_main[0..],
-            "expected {}, got {}",
+        var buf = try std.fmt.bufPrint(&buf_main, "expected {}, got {}", .{
             ttype,
             self.peek().typ,
-        );
+        });
 
         return self.tokenError(self.peek(), buf);
     }
@@ -466,7 +467,7 @@ pub const Parser = struct {
             break :blk orig_name;
         };
 
-        self.setErrContext("function {}", name.lexeme);
+        self.setErrContext("function {}", .{name.lexeme});
 
         _ = try self.consumeSingle(.LeftParen);
 
@@ -529,14 +530,14 @@ pub const Parser = struct {
         var consts = ast.ConstList.init(self.allocator);
         errdefer consts.deinit();
 
-        self.setErrContext("const");
+        self.setErrContext("const", .{});
 
         _ = try self.consumeSingle(.Const);
         _ = try self.consumeSingle(.LeftParen);
 
         while (self.peek().typ != .RightParen) {
             const const_name = try self.consumeSingle(.Identifier);
-            self.setErrContext("const {}", const_name);
+            self.setErrContext("const {}", .{const_name});
 
             _ = try self.consumeSingle(.Equal);
 
@@ -558,18 +559,18 @@ pub const Parser = struct {
     fn parseStructDecl(self: *@This()) !*Node {
         var fields = ast.FieldList.init(self.allocator);
         errdefer fields.deinit();
-        self.setErrContext("struct");
+        self.setErrContext("struct", .{});
 
         _ = try self.consumeSingle(.Struct);
         var name = try self.consumeSingle(.Identifier);
 
-        self.setErrContext("struct {}", name);
+        self.setErrContext("struct {}", .{name});
 
         _ = try self.consumeSingle(.LeftBrace);
 
         while (!self.check(.RightBrace)) {
             const field_name = try self.consumeSingle(.Identifier);
-            self.setErrContext("struct {} field {}", name, field_name);
+            self.setErrContext("struct {} field {}", .{ name, field_name });
 
             const field_type = try self.consumeSingle(.Identifier);
             try fields.append(ast.StructField{
@@ -587,12 +588,12 @@ pub const Parser = struct {
         var fields = ast.TokenList.init(self.allocator);
         errdefer fields.deinit();
 
-        self.setErrContext("enum");
+        self.setErrContext("enum", .{});
 
         _ = try self.consumeSingle(.Enum);
         const name = try self.consumeSingle(.Identifier);
 
-        self.setErrContext("enum {}", name);
+        self.setErrContext("enum {}", .{name});
 
         _ = try self.consumeSingle(.LeftBrace);
 
@@ -606,7 +607,7 @@ pub const Parser = struct {
     }
 
     fn parseTopDecl(self: *@This()) !*Node {
-        self.setErrContext(null);
+        self.setErrContext(null, .{});
 
         return switch (self.peek().typ) {
             .Fn => try self.parseFnDecl(),
@@ -615,7 +616,7 @@ pub const Parser = struct {
             .Enum => try self.parseEnumDecl(),
 
             else => |typ| blk: {
-                return self.doError("expected Fn, Const, Struct, got {}\n", typ);
+                return self.doError("expected Fn, Const, Struct, got {}\n", .{typ});
             },
         };
     }
@@ -837,7 +838,7 @@ pub const Parser = struct {
                 switch (op_tok.typ) {
                     // TODO remove .ColonEqual from language
                     .ColonEqual => {
-                        return self.doError("can not initialize struct field");
+                        return self.doError("can not initialize struct field", .{});
                     },
 
                     .Equal => return try self.mkSet(get.target, get.name, value),
@@ -855,7 +856,7 @@ pub const Parser = struct {
             },
 
             else => |expr_typ| {
-                return self.doError("Invalid assignment target {}", expr_typ);
+                return self.doError("Invalid assignment target {}", .{expr_typ});
             },
         }
     }
@@ -1028,7 +1029,7 @@ pub const Parser = struct {
         // for this to work properly, <expr> must be Variable, since its a type.
         const expr_type = @as(ast.ExprType, expr.*);
         if (expr_type != .Variable) {
-            return self.doError("Expected variable for struct type, got {}", expr_type);
+            return self.doError("Expected variable for struct type, got {}", .{expr_type});
         }
 
         var inits = ast.StructInitList.init(self.allocator);
@@ -1065,11 +1066,10 @@ pub const Parser = struct {
                 // parseInt(i64) on the catch block of parseInt(i32)
                 var i32_num_opt: ?i32 = std.fmt.parseInt(i32, lexeme, 10) catch null;
                 var i64_num: i64 = std.fmt.parseInt(i64, lexeme, 10) catch |err| {
-                    return self.doError(
-                        "Invalid integer (not 32bit or 64bit) '{}': {}",
+                    return self.doError("Invalid integer (not 32bit or 64bit) '{}': {}", .{
                         lexeme,
                         err,
-                    );
+                    });
                 };
 
                 if (i32_num_opt) |i32_num| {
@@ -1124,7 +1124,7 @@ pub const Parser = struct {
             },
 
             else => blk: {
-                return self.doError("expected literal, got {}", curtype);
+                return self.doError("expected literal, got {}", .{curtype});
             },
         };