api(strutil.h): Strutil::string_is_identifier() (#4333)

Signed-off-by: Larry Gritz <[email protected]>
AcademySoftwareFoundation · Jul 16, 2024 · 6a3503a · 6a3503a
1 parent 48f7efa
commit 6a3503a
Show file tree

Hide file tree

Showing 2 changed files with 18 additions and 0 deletions.
diff --git a/src/include/OpenImageIO/strutil.h b/src/include/OpenImageIO/strutil.h
@@ -1116,6 +1116,14 @@ string_view OIIO_UTIL_API parse_line(string_view& str, bool eat = true) noexcept
 /// match.
 string_view OIIO_UTIL_API parse_nested (string_view &str, bool eat=true) noexcept;
 
+/// Does the string follow the lexical rule of a C identifier?
+inline bool
+string_is_identifier(string_view str)
+{
+    // If a leading identifier is the entirety of str, it's an ident.
+    string_view ident = parse_identifier(str);
+    return (!ident.empty() && str.empty());
+}
 
 /// Look within `str` for the pattern:
 ///     head nonwhitespace_chars whitespace

diff --git a/src/libutil/strutil_test.cpp b/src/libutil/strutil_test.cpp
@@ -1498,6 +1498,16 @@ void test_parse ()
     OIIO_CHECK_EQUAL (ss, ""); OIIO_CHECK_EQUAL (s, "");
     s = "(blah"; ss = parse_nested (s);
     OIIO_CHECK_EQUAL (ss, ""); OIIO_CHECK_EQUAL (s, "(blah");
+
+    OIIO_CHECK_EQUAL(string_is_identifier("valid"), true);
+    OIIO_CHECK_EQUAL(string_is_identifier("_underscore"), true);
+    OIIO_CHECK_EQUAL(string_is_identifier("with123numbers"), true);
+    OIIO_CHECK_EQUAL(string_is_identifier("123invalidStart"), false);
+    OIIO_CHECK_EQUAL(string_is_identifier("invalid-char"), false);
+    OIIO_CHECK_EQUAL(string_is_identifier(""), false);
+    OIIO_CHECK_EQUAL(string_is_identifier("a"), true);
+    OIIO_CHECK_EQUAL(string_is_identifier("_"), true);
+    OIIO_CHECK_EQUAL(string_is_identifier("1"), false);
 }