add basics of virtual machine object list

- object: move functions to accept VM pointer, not Allocator

src/compiler.zig

@@ -121,6 +121,7 @@ pub const Compiler = struct {
     scanr: Scanner = undefined,
     chunk: *chunks.Chunk,
     debug_flag: bool = false,
+    vmach: *vm.VM,
 
     pub fn init(
         allocator: *Allocator,
@@ -128,6 +129,7 @@ pub const Compiler = struct {
         stdout: vm.StdOut,
         source: []const u8,
         debug_flag: bool,
+        vmach: *vm.VM,
     ) Compiler {
         return Compiler{
             .src = source,
@@ -136,6 +138,7 @@ pub const Compiler = struct {
             .stdout = stdout,
             .parser = Parser{},
             .debug_flag = debug_flag,
+            .vmach = vmach,
         };
     }
 
@@ -231,8 +234,9 @@ pub const Compiler = struct {
 
     fn string(self: *Compiler) !void {
         const lexeme_len = self.parser.previous.lexeme.len;
+
         try self.emitConstant(values.ObjVal(try objects.copyString(
-            self.allocator,
+            self.vmach,
             self.parser.previous.lexeme[1 .. lexeme_len - 1],
         )));
     }

src/object.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const vm = @import("vm.zig");
 
 const Allocator = std.mem.Allocator;
 
@@ -13,25 +14,36 @@ pub const ObjValue = struct {
 pub const Object = struct {
     otype: ObjType,
     value: ObjValue,
+    next: ?*Object = null,
 };
 
-fn createString(allocator: *Allocator, data: []u8) !*Object {
-    var obj = try allocator.create(Object);
-    obj.otype = ObjType.String;
-    obj.value = ObjValue{ .String = data };
+pub fn allocateObject(
+    vmach: *vm.VM,
+    otype: ObjType,
+    value: ObjValue,
+) !*Object {
+    var obj = try vmach.allocator.create(Object);
+    obj.otype = otype;
+    obj.value = value;
+
+    obj.next = vmach.objs;
+    vmach.objs = obj;
     return obj;
 }
 
-pub fn copyString(allocator: *Allocator, data: []const u8) !*Object {
-    var str = try allocator.alloc(u8, data.len);
-    std.mem.copy(u8, str, data);
+fn createString(vmach: *vm.VM, data: []u8) !*Object {
+    return allocateObject(vmach, ObjType.String, ObjValue{ .String = data });
+}
 
-    return try createString(allocator, str);
+pub fn copyString(vmach: *vm.VM, data: []const u8) !*Object {
+    var str = try vmach.allocator.alloc(u8, data.len);
+    std.mem.copy(u8, str, data);
+    return try createString(vmach, str);
 }
 
 /// Assumes it can take ownership of the given data.
-pub fn takeString(allocator: *Allocator, data: []u8) !*Object {
-    return try createString(allocator, data);
+pub fn takeString(vmach: *vm.VM, data: []u8) !*Object {
+    return try createString(vmach, data);
 }
 
 pub fn printObject(stdout: var, obj: Object) !void {

src/vm.zig

@@ -46,7 +46,9 @@ pub const VM = struct {
 
     stdout: StdOut,
     debug_flag: bool,
-    allocator: *std.mem.Allocator,
+    pub allocator: *std.mem.Allocator,
+
+    objs: ?*objects.Object = null,
 
     fn resetStack(self: *VM) void {
         self.stackTop = 0;
@@ -135,7 +137,7 @@ pub const VM = struct {
             [][]u8{ a, b },
         );
 
-        var val = values.ObjVal(try objects.takeString(self.allocator, res_str));
+        var val = values.ObjVal(try objects.takeString(self, res_str));
         try self.push(val);
     }
 
@@ -273,6 +275,7 @@ pub const VM = struct {
             self.stdout,
             self.src,
             self.debug_flag,
+            self,
         );
         if (!try cmpr.compile(&chk)) {
             return InterpretResult.CompileError;