feat(String): Implement S_substr function

1 files changed, 17 insertions, 0 deletions

diff --git a/String.c b/String.c
index fb003d8..7723525 100644
--- a/String.c
+++ b/String.c
@@ -240,3 +240,20 @@ S_find(String s, char c) {
 
     return index;
 }
+
+String
+S_substr(MemoryManager *mm, String s, usize start, usize length) {
+    if (NULL == s)
+        return NULL;
+
+    struct StringMeta *sm = S_metadata(s);
+
+    if (start >= sm->length || 0 == length)
+        return S_newlen(mm, 0);
+
+    String result = S_newlen(mm, length);
+    strncpy(result, s + start, length);
+    result[length] = '\0';
+
+    return result;
+}