bstr: add bstr_eatstart()

2 files changed, 11 insertions, 0 deletions

diff --git a/bstr.c b/bstr.c
index 809b02e665..fcf73ca828 100644
--- a/bstr.c
+++ b/bstr.c
@@ -198,6 +198,14 @@ struct bstr bstr_getline(struct bstr str, struct bstr *rest)
     return str;
 }
 
+bool bstr_eatstart(struct bstr *s, struct bstr prefix)
+{
+    if (!bstr_startswith(*s, prefix))
+        return false;
+    *s = bstr_cut(*s, prefix.len);
+    return true;
+}
+
 void bstr_lower(struct bstr str)
 {
     for (int i = 0; i < str.len; i++)
diff --git a/bstr.h b/bstr.h
index 15ddf314f3..e8a34b4f2c 100644
--- a/bstr.h
+++ b/bstr.h
@@ -88,6 +88,9 @@ int bstr_parse_utf8_code_length(unsigned char b);
 // line breaks are stripped.
 struct bstr bstr_getline(struct bstr str, struct bstr *rest);
 
+// If s starts with prefix, return true and return the rest of the string in s.
+bool bstr_eatstart(struct bstr *s, struct bstr prefix);
+
 bool bstr_case_startswith(struct bstr s, struct bstr prefix);
 bool bstr_case_endswith(struct bstr s, struct bstr suffix);
 struct bstr bstr_strip_ext(struct bstr str);