vtables, protocol

examples/modules/allocators.sx

@@ -1,47 +1,34 @@
 #import "std.sx";
 
-// --- Allocator protocol ---
+// --- Allocator protocol (inline: ctx + fn-ptrs, no vtable indirection) ---
 
-Allocator :: struct {
-    ctx: *void;
-    alloc_fn: (*void, s64) -> *void;
-    free_fn: (*void, *void) -> void;
+Allocator :: protocol #inline {
+    alloc :: (size: s64) -> *void;
+    dealloc :: (ptr: *void);
 }
 
-allocator_alloc :: (a: Allocator, size: s64) -> *void {
-    a.alloc_fn(a.ctx, size);
-}
-
-allocator_dealloc :: (a: Allocator, ptr: *void) {
-    a.free_fn(a.ctx, ptr);
-}
-
-alloc :: ufcs allocator_alloc;
-dealloc :: ufcs allocator_dealloc;
-
 // --- GPA: general purpose allocator (malloc/free wrapper) ---
 
 GPA :: struct {
     alloc_count: s64;
+
+    create :: (gpa: *GPA) -> Allocator {
+        xx gpa;
+    }
 }
 
-gpa_alloc :: (ctx: *void, size: s64) -> *void {
-    gpa : *GPA = xx ctx;
-    gpa.alloc_count += 1;
-    malloc(size);
+impl Allocator for GPA {
+    alloc :: (self: *GPA, size: s64) -> *void {
+        self.alloc_count += 1;
+        malloc(size);
+    }
+    dealloc :: (self: *GPA, ptr: *void) {
+        self.alloc_count -= 1;
+        free(ptr);
+    }
 }
 
-gpa_free :: (ctx: *void, ptr: *void) {
-    gpa : *GPA = xx ctx;
-    gpa.alloc_count -= 1;
-    free(ptr);
-}
-
-gpa_create :: (gpa: *GPA) -> Allocator {
-    Allocator.{ ctx = gpa, alloc_fn = gpa_alloc, free_fn = gpa_free };
-}
-
-// --- Arena: multi-chunk bump allocator (Zig-inspired) ---
+// --- Arena: multi-chunk bump allocator ---
 
 ArenaChunk :: struct {
     next: *ArenaChunk;
@@ -52,73 +39,71 @@ Arena :: struct {
     first: *ArenaChunk;
     end_index: s64;
     parent: Allocator;
-}
 
-arena_add_chunk :: (a: *Arena, min_size: s64) {
-    prev_cap := if a.first != null then a.first.cap else 0;
-    needed := min_size + 16 + 16;
-    len := (prev_cap + needed) * 3 / 2;
-    raw := a.parent.alloc(len);
-    chunk : *ArenaChunk = xx raw;
-    chunk.next = a.first;
-    chunk.cap = len;
-    a.first = chunk;
-    a.end_index = 0;
-}
-
-arena_alloc :: (ctx: *void, size: s64) -> *void {
-    a : *Arena = xx ctx;
-    aligned := (size + 7) & (0 - 8);
-    if a.first != null {
-        usable := a.first.cap - 16;
-        if a.end_index + aligned <= usable {
-            buf : [*]u8 = xx a.first;
-            ptr := @buf[16 + a.end_index];
-            a.end_index = a.end_index + aligned;
-            return ptr;
-        }
+    add_chunk :: (a: *Arena, min_size: s64) {
+        prev_cap := if a.first != null then a.first.cap else 0;
+        needed := min_size + 16 + 16;
+        len := (prev_cap + needed) * 3 / 2;
+        raw := a.parent.alloc(len);
+        chunk : *ArenaChunk = xx raw;
+        chunk.next = a.first;
+        chunk.cap = len;
+        a.first = chunk;
+        a.end_index = 0;
     }
-    arena_add_chunk(a, aligned);
-    buf : [*]u8 = xx a.first;
-    ptr := @buf[16 + a.end_index];
-    a.end_index = a.end_index + aligned;
-    ptr;
-}
 
-arena_free :: (ctx: *void, ptr: *void) {
-}
+    create :: (a: *Arena, parent: Allocator, size: s64) -> Allocator {
+        a.first = null;
+        a.end_index = 0;
+        a.parent = parent;
+        a.add_chunk(size);
+        xx a;
+    }
 
-arena_create :: (a: *Arena, parent: Allocator, size: s64) -> Allocator {
-    a.first = null;
-    a.end_index = 0;
-    a.parent = parent;
-    arena_add_chunk(a, size);
-    Allocator.{ ctx = a, alloc_fn = arena_alloc, free_fn = arena_free };
-}
+    reset :: (a: *Arena) {
+        if a.first != null {
+            it := a.first.next;
+            while it != null {
+                next := it.next;
+                a.parent.dealloc(it);
+                it = next;
+            }
+            a.first.next = null;
+        }
+        a.end_index = 0;
+    }
 
-arena_reset :: (a: *Arena) {
-    // Keep first chunk (newest/largest), free the rest
-    if a.first != null {
-        it := a.first.next;
+    deinit :: (a: *Arena) {
+        it := a.first;
         while it != null {
             next := it.next;
             a.parent.dealloc(it);
             it = next;
         }
-        a.first.next = null;
+        a.first = null;
+        a.end_index = 0;
     }
-    a.end_index = 0;
 }
 
-arena_deinit :: (a: *Arena) {
-    it := a.first;
-    while it != null {
-        next := it.next;
-        a.parent.dealloc(it);
-        it = next;
+impl Allocator for Arena {
+    alloc :: (self: *Arena, size: s64) -> *void {
+        aligned := (size + 7) & (0 - 8);
+        if self.first != null {
+            usable := self.first.cap - 16;
+            if self.end_index + aligned <= usable {
+                buf : [*]u8 = xx self.first;
+                ptr := @buf[16 + self.end_index];
+                self.end_index = self.end_index + aligned;
+                return ptr;
+            }
+        }
+        self.add_chunk(aligned);
+        buf : [*]u8 = xx self.first;
+        ptr := @buf[16 + self.end_index];
+        self.end_index = self.end_index + aligned;
+        ptr;
     }
-    a.first = null;
-    a.end_index = 0;
+    dealloc :: (self: *Arena, ptr: *void) {}
 }
 
 // --- BufAlloc: bump allocator backed by a user-provided slice ---
@@ -127,29 +112,28 @@ BufAlloc :: struct {
     buf: [*]u8;
     len: s64;
     pos: s64;
-}
 
-buf_alloc :: (ctx: *void, size: s64) -> *void {
-    b : *BufAlloc = xx ctx;
-    aligned := (size + 7) & (0 - 8);
-    if b.pos + aligned > b.len {
-        return null;
+    create :: (b: *BufAlloc, buf: [*]u8, len: s64) -> Allocator {
+        b.buf = buf;
+        b.len = len;
+        b.pos = 0;
+        xx b;
+    }
+
+    reset :: (b: *BufAlloc) {
+        b.pos = 0;
     }
-    ptr := @b.buf[b.pos];
-    b.pos = b.pos + aligned;
-    ptr;
 }
 
-buf_free :: (ctx: *void, ptr: *void) {
-}
-
-buf_create :: (b: *BufAlloc, buf: [*]u8, len: s64) -> Allocator {
-    b.buf = buf;
-    b.len = len;
-    b.pos = 0;
-    Allocator.{ ctx = b, alloc_fn = buf_alloc, free_fn = buf_free };
-}
-
-buf_reset :: (b: *BufAlloc) {
-    b.pos = 0;
+impl Allocator for BufAlloc {
+    alloc :: (self: *BufAlloc, size: s64) -> *void {
+        aligned := (size + 7) & (0 - 8);
+        if self.pos + aligned > self.len {
+            return null;
+        }
+        ptr := @self.buf[self.pos];
+        self.pos = self.pos + aligned;
+        ptr;
+    }
+    dealloc :: (self: *BufAlloc, ptr: *void) {}
 }