Implemented string_view type

include/stdbigos/string_view.h

@@ -0,0 +1,160 @@
+#ifndef STDBIGOS_STRING_VIEW
+#define STDBIGOS_STRING_VIEW
+
+#include <stddef.h>
+
+typedef struct {
+	const char* data;
+	size_t count;
+} string_view;
+
+static inline string_view strv_init(const char* str) {
+	if (!str)
+		return (string_view){NULL, 0};
+	string_view ret;
+	ret.data = str;
+
+	const char* i = str;
+	while (*i) {
+		i++;
+	}
+
+	ret.count = (size_t)(i - str);
+	return ret;
+}
+
+static inline size_t strvlen(string_view strv) {
+	return strv.count;
+}
+
+static inline size_t strvnlen(string_view strv, size_t maxlen) {
+	return strv.count < maxlen ? strv.count : maxlen;
+}
+
+static inline string_view strv_pop_front(string_view strv) {
+	if (strv.count == 0)
+		return strv;
+	strv.data++;
+	strv.count--;
+	return strv;
+}
+
+static inline string_view strv_pop_back(string_view strv) {
+	if (strv.count == 0)
+		return strv;
+	strv.count--;
+	return strv;
+}
+
+static inline int strvcmp(string_view a, string_view b) {
+	size_t min = a.count < b.count ? a.count : b.count;
+
+	for (size_t i = 0; i < min; i++) {
+		unsigned char ca = (unsigned char)a.data[i];
+		unsigned char cb = (unsigned char)b.data[i];
+
+		if (ca < cb)
+			return -1;
+		if (ca > cb)
+			return 1;
+	}
+
+	if (a.count < b.count)
+		return -1;
+	if (a.count > b.count)
+		return 1;
+	return 0;
+}
+
+static inline int strvncmp(string_view a, string_view b, size_t n) {
+	size_t min = a.count < b.count ? a.count : b.count;
+	if (min > n)
+		min = n;
+
+	for (size_t i = 0; i < min; i++) {
+		unsigned char ca = (unsigned char)a.data[i];
+		unsigned char cb = (unsigned char)b.data[i];
+
+		if (ca < cb)
+			return -1;
+		if (ca > cb)
+			return 1;
+	}
+
+	if (a.count < n && a.count < b.count)
+		return -1;
+	if (b.count < n && b.count < a.count)
+		return 1;
+	return 0;
+}
+
+static inline string_view strvchr(string_view strv, int c) {
+	if (!strv.data)
+		return (string_view){NULL, 0};
+	unsigned char ch = (unsigned char)c;
+	while (strv.count > 0 && (unsigned char)strv.data[0] != ch) {
+		strv = strv_pop_front(strv);
+	}
+	return strv;
+}
+
+static inline string_view strvtok(string_view strv, string_view delim) {
+	if (!strv.data)
+		return (string_view){NULL, 0};
+	string_view ret;
+	ret.data = strv.data;
+	ret.count = 0;
+	while (strv.count > 0 && strvchr(delim, *strv.data).count == 0) {
+		strv = strv_pop_front(strv);
+		ret.count++;
+	}
+	return ret;
+}
+
+static inline size_t strvspn(string_view strv, string_view chars) {
+	if (!strv.data)
+		return 0;
+	for (size_t i = 0; i < strv.count; i++) {
+		if (strvchr(chars, strv.data[i]).count == 0)
+			return i;
+	}
+	return strv.count;
+}
+
+static inline size_t strvcspn(string_view strv, string_view chars) {
+	if (!strv.data)
+		return 0;
+	for (size_t i = 0; i < strv.count; i++) {
+		if (strvchr(chars, strv.data[i]).count > 0)
+			return i;
+	}
+	return strv.count;
+}
+
+static inline string_view strvpbrk(string_view strv, string_view breakset) {
+	if (!strv.data)
+		return (string_view){NULL, 0};
+	while (strv.count > 0 && strvchr(breakset, strv.data[0]).count == 0) {
+		strv = strv_pop_front(strv);
+	}
+	return strv;
+}
+
+static inline string_view strvstrv(string_view strv, string_view substrv) {
+	if (!strv.data)
+		return (string_view){NULL, 0};
+	if (substrv.count == 0)
+		return (string_view){strv.data, 0};
+	if (!substrv.data || strv.count < substrv.count)
+		return (string_view){NULL, 0};
+	size_t count = strv.count;
+	strv.count = substrv.count;
+	for (size_t i = 0; i <= count - substrv.count; i++) {
+		if (strvcmp(strv, substrv) == 0)
+			return strv;
+		strv.data++;
+	}
+	return (string_view){NULL, 0};
+}
+
+#endif // !STDBIGOS_STRING_VIEW