Introduce nvim namespace: Move files.

Move files from src/ to src/nvim/.
- src/nvim/ becomes the new root dir for nvim executable sources.
- src/libnvim/ is planned to become root dir of the neovim library.

src/nvim/map.c

@@ -0,0 +1,91 @@
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "map.h"
+#include "map_defs.h"
+#include "vim.h"
+#include "memory.h"
+
+#include "lib/khash.h"
+
+typedef struct {
+  void *ptr;
+} Value;
+
+KHASH_MAP_INIT_STR(Map, Value)
+
+struct map {
+  khash_t(Map) *table;
+};
+
+Map *map_new()
+{
+  Map *rv = xmalloc(sizeof(Map));
+  rv->table = kh_init(Map);
+  return rv;
+}
+
+void map_free(Map *map)
+{
+  kh_clear(Map, map->table);
+  kh_destroy(Map, map->table);
+  free(map);
+}
+
+void *map_get(Map *map, const char *key)
+{
+  khiter_t k;
+
+  if ((k = kh_get(Map, map->table, key)) == kh_end(map->table)) {
+    return NULL;
+  }
+
+  return kh_val(map->table, k).ptr;
+}
+
+bool map_has(Map *map, const char *key)
+{
+  return map_get(map, key) != NULL;
+}
+
+void *map_put(Map *map, const char *key, void *value)
+{
+  int ret;
+  void *rv = NULL;
+  khiter_t k = kh_put(Map, map->table, key, &ret);
+  Value val = {.ptr = value};
+
+  if (!ret) {
+    // key present, return the current value
+    rv = kh_val(map->table, k).ptr;
+    kh_del(Map, map->table, k);
+  }
+
+  kh_val(map->table, k) = val;
+
+  return rv;
+}
+
+void *map_del(Map *map, const char *key)
+{
+  void *rv = NULL;
+  khiter_t k;
+
+  if ((k = kh_get(Map, map->table, key)) != kh_end(map->table)) {
+    rv = kh_val(map->table, k).ptr;
+    kh_del(Map, map->table, k);
+  }
+
+  return rv;
+}
+
+void map_foreach(Map *map, key_value_cb cb)
+{
+  const char *key;
+  Value value;
+
+  kh_foreach(map->table, key, value, {
+    cb(map, (const char *)key, value.ptr);
+  });
+}
+