Change how types handle metamethods

1 files changed, 13 insertions, 221 deletions

diff --git a/stdlib/metamethods.c b/stdlib/metamethods.c
index 6c8583f3..28d97730 100644
--- a/stdlib/metamethods.c
+++ b/stdlib/metamethods.c
@@ -15,247 +15,40 @@
 #include "text.h"
 #include "util.h"
 
-
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wstack-protector"
 PUREFUNC public uint64_t generic_hash(const void *obj, const TypeInfo_t *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 StructInfo: {
-        if (type->StructInfo.num_fields == 0) {
-            return 0;
-        } else if (type->StructInfo.num_fields == 1) {
-            return generic_hash(obj, type->StructInfo.fields[0].type);
-        } else {
-            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));
-        }
-    }
-    case EnumInfo: {
-        int32_t tag = *(int32_t*)obj;
-        uint32_t components[2] = {(uint32_t)tag, 0};
-
-        const TypeInfo_t *value = type->EnumInfo.tags[tag-1].type;
-        if (value && value->size > 0) {
-            ptrdiff_t byte_offset = sizeof(int32_t);
-            if (value->align && byte_offset % value->align > 0)
-                byte_offset += value->align - (byte_offset % value->align);
-            components[1] = generic_hash(obj + byte_offset, value);
-        }
-        return siphash24((void*)components, sizeof(components));
+    if (type->metamethods.hash)
+        return type->metamethods.hash(obj, type);
 
-    }
-    case CustomInfo: 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));
-    }
-    }
+    return siphash24((void*)obj, (size_t)(type->size));
 }
-#pragma GCC diagnostic pop
 
 PUREFUNC public int32_t generic_compare(const void *x, const void *y, const TypeInfo_t *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$compare(x, y, type);
-    case OptionalInfo: {
-        bool x_is_null = is_null(x, type->OptionalInfo.type);
-        bool y_is_null = is_null(y, type->OptionalInfo.type);
-        if (x_is_null && y_is_null) return 0;
-        else if (x_is_null != y_is_null) return (int32_t)y_is_null - (int32_t)x_is_null;
-        else return generic_compare(x, y, type->OptionalInfo.type);
-    }
-    case StructInfo: {
-        ptrdiff_t byte_offset = 0;
-        ptrdiff_t bit_offset = 0;
-        for (int i = 0; i < type->StructInfo.num_fields; i++) {
-            NamedType_t field = type->StructInfo.fields[i];
-            if (field.type == &Bool$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;
-    }
-    case EnumInfo: {
-        int32_t x_tag = *(int32_t*)x;
-        int32_t y_tag = *(int32_t*)y;
-        if (x_tag != y_tag)
-            return x_tag > y_tag ? 1 : -1;
+    if (type->metamethods.compare)
+        return type->metamethods.compare(x, y, type);
 
-        const TypeInfo_t *value = type->EnumInfo.tags[x_tag-1].type;
-        if (value && value->size > 0) {
-            ptrdiff_t byte_offset = sizeof(int32_t);
-            if (value->align && byte_offset % value->align > 0)
-                byte_offset += value->align - (byte_offset % value->align);
-            return generic_compare(x + byte_offset, y + byte_offset, value);
-        }
-        return 0;
-    }
-    case CustomInfo: 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));
-    }
+    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_t *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 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 StructInfo: case EnumInfo: 
-        return (generic_compare(x, y, type) == 0);
-    case CustomInfo: 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);
-    }
+    if (type->metamethods.equal)
+        return type->metamethods.equal(x, y, type);
+
+    return (generic_compare(x, y, type) == 0);
 }
 
 public Text_t generic_as_text(const void *obj, bool colorize, const TypeInfo_t *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 StructInfo: {
-        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->metamethods.as_text)
+        fail("No text metamethod provided for type!");
 
-            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$concat(text, Text(")"));
-    }
-    case EnumInfo: {
-        if (!obj) return Text$from_str(type->EnumInfo.name);
-
-        int32_t tag = *(int32_t*)obj;
-        NamedType_t value = type->EnumInfo.tags[tag-1];
-        if (!value.type || value.type->size == 0)
-            return Text$format(colorize ? "\x1b[36;1m%s\x1b[m.\x1b[1m%s\x1b[m" : "%s.%s", type->EnumInfo.name, value.name);
-
-        ptrdiff_t byte_offset = sizeof(int32_t);
-        if (value.type->align && byte_offset % value.type->align > 0)
-            byte_offset += value.type->align - (byte_offset % value.type->align);
-        return Text$concat(Text$format(colorize ? "\x1b[36;1m%s\x1b[m." : "%s.", type->EnumInfo.name),
-                           generic_as_text(obj + byte_offset, colorize, value.type));
-    }
-    case CustomInfo: 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: fail("Invalid type tag: %d", type->tag);
-    }
+    return type->metamethods.as_text(obj, colorize, type);
 }
 
 public int generic_print(const void *obj, bool colorize, const TypeInfo_t *type)
@@ -264,5 +57,4 @@ public int generic_print(const void *obj, bool colorize, const TypeInfo_t *type)
     return Text$print(stdout, text) + printf("\n");
 }
 
-
 // vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0