1 files changed, 58 insertions, 0 deletions
diff --git a/vendor/nunicode/src/libnu/tolower.c b/vendor/nunicode/src/libnu/tolower.c
new file mode 100644
index 0000000000..1ce229d370
--- /dev/null
+++ b/vendor/nunicode/src/libnu/tolower.c
@@ -0,0 +1,58 @@
+#include <assert.h>
+
+#include <libnu/casemap.h>
+
+#ifdef NU_WITH_TOLOWER
+
+#include <libnu/casemap_internal.h>
+#include "gen/_tolower.c"
+
+/* in nu_casemap_read (UTF-8), zero-terminated */
+static const char *__nu_final_sigma = "ς";
+
+const char* nu_tolower(uint32_t codepoint) {
+	return _nu_to_something(codepoint, NU_TOLOWER_G, NU_TOLOWER_G_SIZE,
+		NU_TOLOWER_VALUES_C, NU_TOLOWER_VALUES_I, NU_TOLOWER_COMBINED);
+}
+
+const char* _nu_tolower(const char *encoded, const char *limit, nu_read_iterator_t read,
+	uint32_t *u, const char **transform,
+	void *context) {
+
+	(void)(context);
+
+	uint32_t _u = 0;
+	const char *np = read(encoded, &_u);
+
+	if (u != 0) {
+		*u = _u;
+	}
+
+	/* handling of 0x03A3 ('Σ')
+	 *
+	 * this is the only language-independent exception described in
+	 * SpecialCasing.txt (Unicode 7.0) */
+
+	assert(nu_casemap_read == nu_utf8_read);
+
+	if (_u == 0x03A3) {
+		if (np >= limit) {
+			*transform = __nu_final_sigma;
+			return np;
+		}
+
+		uint32_t nu = 0;
+		read(np, &nu);
+
+		if (nu == 0) {
+			*transform = __nu_final_sigma;
+			return np;
+		}
+	}
+
+	*transform = nu_tolower(_u);
+
+	return np;
+}
+
+#endif /* NU_WITH_TOLOWER */