Separate out implementation to make looking at code files easier

1 files changed, 61 insertions, 0 deletions

diff --git a/symtable.c b/symtable.c
new file mode 100644
index 0000000..a159b69
--- /dev/null
+++ b/symtable.c
@@ -0,0 +1,61 @@
+/* Copyright (C) 2025 Aryadev Chavali
+
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the Unlicense for details.
+
+ * You may distribute and modify this code under the terms of the Unlicense,
+ * which you should have received a copy of along with this program.  If not,
+ * please go to <https://unlicense.org/>.
+
+ * Created: 2025-08-19
+ * Description: Symbol Table implementation
+ */
+
+#include "./base.h"
+
+#include <malloc.h>
+#include <string.h>
+
+u64 djb2(sv_t string)
+{
+  u64 hash = 5381;
+  for (u64 i = 0; i < string.size; ++i)
+    hash = string.data[i] + (hash + (hash << 5));
+  return hash;
+}
+
+void sym_table_init(sym_table_t *table)
+{
+  table->capacity = MAX(table->capacity, SYM_TABLE_INIT_SIZE);
+  table->count    = 0;
+  vec_make((void **)&table->entries, table->capacity * sizeof(*table->entries));
+}
+
+sv_t sym_table_find(sym_table_t *table, sv_t sv)
+{
+  // TODO: Deal with resizing this when table->count > table->size / 2
+  u64 index = djb2(sv) & (table->capacity - 1);
+
+  for (sv_t comp  = table->entries[index]; comp.data; index += 1,
+            index = index & (table->capacity - 1), comp = table->entries[index])
+    // Is it present in the table?
+    if (sv.size == comp.size && strncmp(sv.data, comp.data, sv.size) == 0)
+      return comp;
+
+  // Otherwise we need to duplicate and make it permanently interned
+  sv_t newsv            = sv_copy(sv);
+  table->entries[index] = newsv;
+  ++table->count;
+
+  return newsv;
+}
+
+void sym_table_cleanup(sym_table_t *table)
+{
+  for (u64 i = 0; i < table->capacity; ++i)
+    if (table->entries[i].data)
+      free(table->entries[i].data);
+  vec_free((void **)&table->entries);
+  memset(table, 0, sizeof(*table));
+}