feat(sv): add string view lib

app/strings.c

@@ -0,0 +1,49 @@
+#include "c-libs/dyn-arr.h"
+#include "c-libs/string-view.h"
+#include <ctype.h>
+
+int main() {
+  StringView sv = sv_new("Hello World\n");
+
+  sv_puts(sv);
+  sv_puts(sv_drop(sv_shrink(sv, 3), 2));
+  sv_puts(sv_drop(sv_shrink(sv, 5), 9));
+
+  StringView sv2 = sv_new("AAA Test BBB");
+  sv_puts(sv2);
+  puts("");
+  sv2 = sv_seek(sv2, ' ');
+  sv_puts(sv2);
+  puts("");
+  sv2 = sv_seek_back(sv2, ' ');
+  sv_puts(sv2);
+  puts("");
+
+  StringView csv = sv_new("  100 ,  2000,   10  ,1,871");
+
+  StringView *values = NULL;
+  darr_init(values, 0);
+
+  while (sv_len(csv)) {
+    StringView item = sv_split_at(&csv, ',');
+    darr_push(values, sv_trim(item, isspace));
+  }
+
+  char *all = sv_concat_with_sep(values, darr_size(values), sv_new("::"));
+  puts(all);
+
+  darr_clear(values);
+
+  StringView ccsv = sv_new(all);
+  while (sv_len(ccsv)) {
+    StringView item = sv_split_at_sv(&ccsv, sv_new("::"));
+    darr_push(values, sv_trim(item, isspace));
+  }
+
+  char *all2 = sv_concat_with_sep(values, darr_size(values), sv_new("-+-"));
+  puts(all2);
+
+  free(all);
+  free(all2);
+  darr_free(values);
+}