feat: (str) str_new_*, str_free

lib/inc/str.h

@@ -0,0 +1,19 @@
+#ifndef CUTILS_STR_H_
+#define CUTILS_STR_H_
+
+#include <stddef.h>
+
+typedef struct
+{
+    char *str;
+    size_t len;
+    size_t cap;
+} str_t;
+
+void str_new (str_t *str);
+void str_new_cap (str_t *str, size_t want_cap);
+void str_new_from (str_t *str, const char *src);
+void str_new_from_len (str_t *str, const char *src, size_t len);
+void str_free (str_t *str);
+
+#endif // CUTILS_STR_H_

lib/str.c

@@ -0,0 +1,49 @@
+#include "str.h"
+#include <stdlib.h>
+#include <string.h>
+#include "common.h"
+
+#define STR_MIN_ALLOC 64
+
+void
+str_new (str_t *str)
+{
+    str->str = smalloc (STR_MIN_ALLOC * sizeof (char));
+    str->len = 0;
+    str->cap = STR_MIN_ALLOC;
+}
+
+void
+str_new_cap (str_t *str, size_t want_cap)
+{
+    size_t cap;
+
+    cap = max (next_pow_of_two (want_cap), STR_MIN_ALLOC);
+    str->str = smalloc (cap);
+    str->len = 0;
+    str->cap = cap;
+}
+
+inline void
+str_new_from (str_t *str, const char *src)
+{
+    str_new_from_len (str, src, strlen (src));
+}
+
+void
+str_new_from_len (str_t *str, const char *src, size_t len)
+{
+    size_t cap;
+
+    cap = max (next_pow_of_two (len + 1), STR_MIN_ALLOC);
+    str->str = smalloc (cap * sizeof (char));
+    str->len = len;
+    str->cap = cap;
+    strcpy (str->str, src);
+}
+
+inline void
+str_free (str_t *str)
+{
+    free (str->str);
+}