1 files changed, 124 insertions, 0 deletions
diff --git a/stdlib/metamethods.c b/stdlib/metamethods.c
new file mode 100644
index 00000000..9b0560ab
--- /dev/null
+++ b/stdlib/metamethods.c
@@ -0,0 +1,124 @@
+// Metamethods are methods that all types share for hashing, equality, comparison, and textifying
+
+#include <stdint.h>
+#include <string.h>
+
+#include "arrays.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"
+
+
+PUREFUNC public uint64_t generic_hash(const void *obj, const TypeInfo *type)
+{
+    switch (type->tag) {
+    case TextInfo: return Text$hash((void*)obj);
+    case ArrayInfo: return Array$hash(obj, type);
+    case ChannelInfo: return Channel$hash((Channel_t**)obj, type);
+    case TableInfo: return Table$hash(obj, type);
+    case OptionalInfo: return is_null(obj, type->OptionalInfo.type) ? 0 : generic_hash(obj, type->OptionalInfo.type);
+    case EmptyStructInfo: return 0;
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
+        if (!type->CustomInfo.hash)
+            goto hash_data;
+        return type->CustomInfo.hash(obj, type);
+    case PointerInfo: case FunctionInfo: case TypeInfoInfo: case OpaqueInfo: default: {
+      hash_data:;
+        return siphash24((void*)obj, (size_t)(type->size));
+    }
+    }
+}
+
+PUREFUNC public int32_t generic_compare(const void *x, const void *y, const TypeInfo *type)
+{
+    if (x == y) return 0;
+
+    switch (type->tag) {
+    case PointerInfo: case FunctionInfo: return Pointer$compare(x, y, type);
+    case TextInfo: return Text$compare(x, y);
+    case ArrayInfo: return Array$compare(x, y, type);
+    case ChannelInfo: return Channel$compare((Channel_t**)x, (Channel_t**)y, type);
+    case TableInfo: return Table$compare(x, y, type);
+    case OptionalInfo: {
+        bool x_is_null = is_null(x, type->OptionalInfo.type);
+        bool y_is_null = is_null(y, type->OptionalInfo.type);
+        if (x_is_null && y_is_null) return 0;
+        else if (x_is_null != y_is_null) return (int32_t)y_is_null - (int32_t)x_is_null;
+        else return generic_compare(x, y, type->OptionalInfo.type);
+    }
+    case EmptyStructInfo: return 0;
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
+        if (!type->CustomInfo.compare)
+            goto compare_data;
+        return type->CustomInfo.compare(x, y, type);
+    case TypeInfoInfo: case OpaqueInfo: default:
+      compare_data:
+        return (int32_t)memcmp((void*)x, (void*)y, (size_t)(type->size));
+    }
+}
+
+PUREFUNC public bool generic_equal(const void *x, const void *y, const TypeInfo *type)
+{
+    if (x == y) return true;
+
+    switch (type->tag) {
+    case PointerInfo: case FunctionInfo: return Pointer$equal(x, y, type);
+    case TextInfo: return Text$equal(x, y);
+    case ArrayInfo: return Array$equal(x, y, type);
+    case ChannelInfo: return Channel$equal((Channel_t**)x, (Channel_t**)y, type);
+    case TableInfo: return Table$equal(x, y, type);
+    case EmptyStructInfo: return true;
+    case OptionalInfo: {
+        bool x_is_null = is_null(x, type->OptionalInfo.type);
+        bool y_is_null = is_null(y, type->OptionalInfo.type);
+        if (x_is_null && y_is_null) return true;
+        else if (x_is_null != y_is_null) return false;
+        else return generic_equal(x, y, type->OptionalInfo.type);
+    }
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
+        if (!type->CustomInfo.equal)
+            goto use_generic_compare;
+        return type->CustomInfo.equal(x, y, type);
+    case TypeInfoInfo: case OpaqueInfo: default:
+      use_generic_compare:
+        return (generic_compare(x, y, type) == 0);
+    }
+}
+
+public Text_t generic_as_text(const void *obj, bool colorize, const TypeInfo *type)
+{
+    switch (type->tag) {
+    case PointerInfo: return Pointer$as_text(obj, colorize, type);
+    case FunctionInfo: return Func$as_text(obj, colorize, type);
+    case TextInfo: return Text$as_text(obj, colorize, type);
+    case ArrayInfo: return Array$as_text(obj, colorize, type);
+    case ChannelInfo: return Channel$as_text((Channel_t**)obj, colorize, type);
+    case TableInfo: return Table$as_text(obj, colorize, type);
+    case TypeInfoInfo: return Type$as_text(obj, colorize, type);
+    case OptionalInfo: return Optional$as_text(obj, colorize, type);
+    case EmptyStructInfo: return colorize ?
+                      Text$concat(Text("\x1b[0;1m"), Text$from_str(type->EmptyStructInfo.name), Text("\x1b[m()"))
+                          : Text$concat(Text$from_str(type->EmptyStructInfo.name), Text("()"));
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
+        if (!type->CustomInfo.as_text)
+            fail("No text function provided for type!\n");
+        return type->CustomInfo.as_text(obj, colorize, type);
+    case OpaqueInfo: return Text("???");
+    default: errx(1, "Invalid type tag: %d", type->tag);
+    }
+}
+
+public int generic_print(const void *obj, bool colorize, const TypeInfo *type)
+{
+    Text_t text = generic_as_text(obj, colorize, type);
+    return Text$print(stdout, text) + printf("\n");
+}
+
+
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0