2 files changed, 169 insertions, 2 deletions

diff --git a/src/string.c b/src/string.c
index 6e1ba40..dce00f3 100644
--- a/src/string.c
+++ b/src/string.c
@@ -1,11 +1,156 @@
 #include "config.h"
 
+#include <assert.h>
+#include <errno.h>
 #include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "logerr.h"
+#include "math.h"
+#include "util.h"
 
 #include "string.h"
 
 
+
 struct String {
-	char *bytes;
-	size_t length;
+	const size_t length;
+	const uint8_t *const bytes;
 };
+
+
+
+int
+string_new_with(
+	const char *const string,
+	const size_t length,
+	const struct String **const out
+) {
+	int rc = -1;
+
+	const struct String *ret = NULL;
+	const uint8_t *bytes = NULL;
+
+	ret = malloc(sizeof(*ret));
+	if (ret == NULL) {
+		logerr("malloc(): %s", strerror(errno));
+		goto out;
+	}
+
+	bytes = malloc(length + NULL_TERMINATOR);
+	if (bytes == NULL) {
+		logerr("malloc(): %s", strerror(errno));
+		goto out;
+	}
+
+	memcpy((void *)bytes, string, length);
+	memcpy((void *)(bytes + length), "", NULL_TERMINATOR);
+	memcpy((void *)ret, &(struct String) {
+		.length = length,
+		.bytes  = bytes,
+	}, sizeof(*ret));
+	*out = ret;
+	rc = 0;
+out:
+	if (rc) {
+		if (bytes != NULL) {
+			free((void *)bytes);
+			ret = NULL;
+		}
+		if (ret != NULL) {
+			free((void *)ret);
+			ret = NULL;
+		}
+	}
+	return rc;
+}
+
+int
+string_new(const char *const string, const struct String **const out) {
+	return string_new_with(string, strlen(string), out);
+}
+
+void
+string_free(const struct String **const s) {
+	free((void *)(*s)->bytes);
+	free((void *)(*s));
+	*s = NULL;
+}
+
+const char *
+cstr(const struct String *s) {
+	return (const char *)s->bytes;
+}
+
+enum Comparison
+string_equal(const struct String *const s1, const struct String *const s2) {
+	if (s1->length < s2->length) {
+		return Comparison_LT;
+	} else if (s1->length > s2->length) {
+		return Comparison_GT;
+	} else {
+		const int ret = strcmp((const char *)s1->bytes, (const char *)s2->bytes);
+		if (ret < 0) {
+			return Comparison_LT;
+		} else if (ret > 0) {
+			return Comparison_GT;
+		} else {
+			return Comparison_EQ;
+		}
+	}
+}
+
+int
+string_append(
+	const struct String *const s1,
+	const struct String *const s2,
+	const struct String **const out
+) {
+	int rc = -1;
+
+	const struct String *ret = NULL;
+	const uint8_t *bytes = NULL;
+
+	size_t length;
+	if (add_size(s1->length, s2->length, &length)) {
+		logerr("add_size()");
+		goto out;
+	}
+
+	ret = malloc(sizeof(*ret));
+	if (ret == NULL) {
+		logerr("malloc(): %s", strerror(errno));
+		goto out;
+	}
+
+	bytes = malloc(length + NULL_TERMINATOR);
+	if (bytes == NULL) {
+		logerr("malloc(): %s", strerror(errno));
+		goto out;
+	}
+
+	memcpy((void *)bytes, s1->bytes, s1->length);
+	memcpy((void *)(bytes + s1->length), s2->bytes, s2->length);
+	memcpy((void *)(bytes + length), "", NULL_TERMINATOR);
+	memcpy((void *)ret, &(struct String) {
+		.length = length,
+		.bytes  = bytes,
+	}, sizeof(*ret));
+	*out = ret;
+	rc = 0;
+out:
+	if (rc) {
+		if (bytes != NULL) {
+			free((void *)bytes);
+			bytes = NULL;
+		}
+		if (ret != NULL) {
+			free((void *)ret);
+			ret = NULL;
+		}
+	}
+	return rc;
+}
diff --git a/src/string.h b/src/string.h
index 2a60e26..e945b40 100644
--- a/src/string.h
+++ b/src/string.h
@@ -1 +1,23 @@
 struct String;
+
+enum Comparison {
+	Comparison_LT,
+	Comparison_EQ,
+	Comparison_GT,
+};
+
+int
+string_new(const char *const string, const struct String **out);
+
+void
+string_free(const struct String **const s);
+
+enum Comparison
+string_equal(const struct String *const s1, const struct String *const s2);
+
+int
+string_append(
+	const struct String *const s1,
+	const struct String *const s2,
+	const struct String **const out
+);