Change how types handle metamethods

1 files changed, 170 insertions, 0 deletions

diff --git a/stdlib/structs.c b/stdlib/structs.c
new file mode 100644
index 00000000..c23e4b7b
--- /dev/null
+++ b/stdlib/structs.c
@@ -0,0 +1,170 @@
+// Metamethods for structs
+
+#include <stdint.h>
+#include <string.h>
+
+#include "arrays.h"
+#include "bools.h"
+#include "channels.h"
+#include "functiontype.h"
+#include "metamethods.h"
+#include "optionals.h"
+#include "pointers.h"
+#include "siphash.h"
+#include "tables.h"
+#include "text.h"
+#include "util.h"
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstack-protector"
+PUREFUNC public uint64_t Struct$hash(const void *obj, const TypeInfo_t *type)
+{
+    if (type->StructInfo.num_fields == 0)
+        return 0;
+
+    if (type->StructInfo.num_fields == 1)
+        return generic_hash(obj, type->StructInfo.fields[0].type);
+
+    uint32_t field_hashes[type->StructInfo.num_fields] = {};
+    ptrdiff_t byte_offset = 0;
+    ptrdiff_t bit_offset = 0;
+    for (int i = 0; i < type->StructInfo.num_fields; i++) {
+        NamedType_t field = type->StructInfo.fields[i];
+        if (field.type == &Bool$info) {
+            bool b = ((*(char*)(obj + byte_offset)) >> bit_offset) & 0x1;
+            field_hashes[i] = (uint32_t)b;
+            bit_offset += 1;
+            if (bit_offset >= 8) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+        } else {
+            if (bit_offset > 0) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+            if (field.type->align && byte_offset % field.type->align > 0)
+                byte_offset += field.type->align - (byte_offset % field.type->align);
+            field_hashes[i] = generic_hash(obj + byte_offset, field.type);
+            byte_offset += field.type->size;
+        }
+    }
+    return siphash24((void*)field_hashes, sizeof(field_hashes));
+}
+#pragma GCC diagnostic pop
+
+PUREFUNC public int32_t Struct$compare(const void *x, const void *y, const TypeInfo_t *type)
+{
+    if (x == y)
+        return 0;
+
+    ptrdiff_t byte_offset = 0;
+    ptrdiff_t bit_offset = 0;
+    for (int i = 0; i < type->StructInfo.num_fields; i++) {
+        NamedType_t field = type->StructInfo.fields[i];
+        if (field.type == &Bool$info) {
+            bool bx = ((*(char*)(x + byte_offset)) >> bit_offset) & 0x1;
+            bool by = ((*(char*)(y + byte_offset)) >> bit_offset) & 0x1;
+            if (bx != by)
+                return (int32_t)bx - (int32_t)by;
+            bit_offset += 1;
+            if (bit_offset >= 8) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+        } else {
+            if (bit_offset > 0) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+            if (field.type->align && byte_offset % field.type->align > 0)
+                byte_offset += field.type->align - (byte_offset % field.type->align);
+            int32_t cmp = generic_compare(x + byte_offset, y + byte_offset, field.type);
+            if (cmp != 0)
+                return cmp;
+            byte_offset += field.type->size;
+        }
+    }
+    return 0;
+}
+
+PUREFUNC public bool Struct$equal(const void *x, const void *y, const TypeInfo_t *type)
+{
+    if (x == y)
+        return true;
+
+    ptrdiff_t byte_offset = 0;
+    ptrdiff_t bit_offset = 0;
+    for (int i = 0; i < type->StructInfo.num_fields; i++) {
+        NamedType_t field = type->StructInfo.fields[i];
+        if (field.type == &Bool$info) {
+            bool bx = ((*(char*)(x + byte_offset)) >> bit_offset) & 0x1;
+            bool by = ((*(char*)(y + byte_offset)) >> bit_offset) & 0x1;
+            if (bx != by)
+                return false;
+            bit_offset += 1;
+            if (bit_offset >= 8) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+        } else {
+            if (bit_offset > 0) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+            if (field.type->align && byte_offset % field.type->align > 0)
+                byte_offset += field.type->align - (byte_offset % field.type->align);
+            if (!generic_equal(x + byte_offset, y + byte_offset, field.type))
+                return false;
+            byte_offset += field.type->size;
+        }
+    }
+    return true;
+}
+
+PUREFUNC public Text_t Struct$as_text(const void *obj, bool colorize, const TypeInfo_t *type)
+{
+    if (!obj) return Text$from_str(type->StructInfo.name);
+
+    if (type->StructInfo.is_secret)
+        return Text$format(colorize ? "\x1b[0;1m%s\x1b[m(...)" : "%s(...)", type->StructInfo.name);
+
+    Text_t text = Text$format(colorize ? "\x1b[0;1m%s\x1b[m(" : "%s(", type->StructInfo.name);
+    ptrdiff_t byte_offset = 0;
+    ptrdiff_t bit_offset = 0;
+    for (int i = 0; i < type->StructInfo.num_fields; i++) {
+        NamedType_t field = type->StructInfo.fields[i];
+        if (i > 0)
+            text = Text$concat(text, Text(", "));
+
+        if (type->StructInfo.num_fields > 1)
+            text = Text$concat(text, Text$from_str(field.name), Text("="));
+
+        if (field.type == &Bool$info) {
+            bool b = ((*(char*)(obj + byte_offset)) >> bit_offset) & 0x1;
+            text = Text$concat(text, Text$from_str(colorize ? (b ? "\x1b[35myes\x1b[m" : "\x1b[35mno\x1b[m") : (b ? "yes" : "no")));
+            bit_offset += 1;
+            if (bit_offset >= 8) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+        } else {
+            if (bit_offset > 0) {
+                byte_offset += 1;
+                bit_offset = 0;
+            }
+            if (field.type->align && byte_offset % field.type->align > 0)
+                byte_offset += field.type->align - (byte_offset % field.type->align);
+            text = Text$concat(text, generic_as_text(obj + byte_offset, colorize, field.type));
+            byte_offset += field.type->size;
+        }
+    }
+    return Text$concat(text, Text(")"));
+}
+
+PUREFUNC public bool Struct$is_none(const void *obj, const TypeInfo_t *type)
+{
+    return *(bool*)(obj + type->size);
+}
+
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0