1 files changed, 108 insertions, 0 deletions
diff --git a/const_strings.h b/const_strings.h
new file mode 100644
index 0000000..3f13b95
--- /dev/null
+++ b/const_strings.h
@@ -0,0 +1,108 @@
+#ifndef CONST_STRINGS_H_
+#define CONST_STRINGS_H_
+
+#include <string.h>
+#include <stdio.h>
+#include <stdbool.h>
+
+typedef struct {
+  char* data;
+  int len;
+} const_string;
+
+
+const_string cs_from_parts(char* data, int len);
+const_string cs_from_cstr(char* cstr);
+const_string cs_slice(const_string src, int from, int to);
+const_string cs_chop_delim(const_string *src, char delim);
+int cs_find_delim(const_string str, char delim);
+void cs_print(char *format, const_string str);
+
+#define CS(cstr) cs_from_parts(cstr, sizeof(cstr) - 1)
+#define CS_STATIC(cstr) {.data = cstr, .len = sizeof(cstr) - 1}
+
+#endif // STRINGS_H_
+
+
+#ifdef CONST_STRINGS_IMPLEMENTATION
+
+const_string cs_from_parts(char* data, int len) {
+  const_string str;
+  str.data = data;
+  str.len = len;
+  
+  return str;
+}
+
+const_string cs_from_cstr(char* cstr) {
+  return cs_from_parts(cstr, strlen(cstr));
+}
+
+char* cs_to_cstr(const_string str) {
+  str.data[str.len] = '\0';
+  return str.data;
+}
+
+const_string cs_slice(const_string src, int from, int to) {
+  if (from > src.len) {
+	return src;
+  }
+
+  int new_from;
+  if (from <= 0) {
+	new_from = 1;
+  } 
+  new_from -= 1;
+
+  int new_len;
+  if (to > src.len) {
+	new_len = src.len;
+  } else {
+	new_len = to;
+  }
+
+  return cs_from_parts(src.data + new_from, new_len);
+}
+
+const_string cs_chop_delim(const_string *str, char delim) {
+  int n;
+  for (n = 0; n < str->len && str->data[n] != delim; n++) {}
+
+  const_string result = cs_from_parts(str->data, n);
+
+  if (n < str->len) {
+	str->len -= n + 1;
+	str->data += n + 1;
+  } else {
+	str->len -= n;
+	str->data += n;
+  }
+  
+  return result;
+}
+
+int cs_find_delim(const_string str, char delim) {
+  int n;
+  for (n = 0; n < str.len && str.data[n] != delim; n++) {}
+
+  if (n < str.len) {
+	return n;
+  }
+  return -1;
+}
+
+bool cs_eq(const_string str1, const_string str2) {
+  if (str1.len != str2.len) {
+	return false;
+  }
+  return memcmp(str1.data, str2.data, str1.len) == 0;
+}
+
+void cs_print(char *format, const_string str) {
+  char buf[str.len + 1];
+  memcpy(buf, str.data, str.len);
+  buf[str.len] = '\0';
+  printf(format, buf);
+}
+
+#endif // STRINGS_IMPLEMENTATION