Established length-based strings

include/lenstr.h

@@ -0,0 +1,22 @@
+#ifndef LENSTR_H
+#define LENSTR_H
+/* Length-based strings
+ * and methods to go with them. */
+
+#define PrintStr(str) printf("%.*s\n", str.length, str.chars)
+#define StrLit(s) (string) {s, sizeof(s)-1}
+
+typedef struct {
+    char *chars;
+    size_t length;
+} string;
+
+string CStyleToLengthString_Assign(char *cstr); // StrLit(s) macro but in function form.
+string CStyleToLengthString_Copy(char *cstr);
+
+string StringCopy(string str);
+
+string StringSlice_Index(string str, size_t starti, size_t endi);
+string StringSlice_Length(string str, size_t starti, size_t length);
+
+#endif // LENSTR_H

src/lenstr.c

@@ -0,0 +1,57 @@
+#include "../include/lenstr.h"
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+string CStyleToLengthString_Assign(char *cstr)
+{
+    string x;
+    x.chars = cstr;
+    x.length = strlen(x.chars);
+    return x;
+}
+
+string CStyleToLengthString_Copy(char *cstr)
+{
+    string x;
+    x.length = strlen(cstr);
+    x.chars = malloc(sizeof(char) * x.length); // Should I add +1 here for null terminator?
+    char *d = x.chars;
+    char *s = cstr;
+    while (*d++ = *s++);
+    return x;
+}
+
+// Research and implement memory arenas before implementing this
+// char *LengthStringToCStyle(string str)
+// {
+//     char *cstr;
+//     cstr = malloc
+// }
+
+string StringCopy(string str)
+{
+    string x;
+    x.length = str.length;
+    x.chars = malloc(sizeof(char) * x.length);
+    for (int i = 0; i < x.length; i++) {
+        x.chars[i] = str.chars[i];
+    }
+    return x;
+}
+
+string StringSlice_Index(string str, size_t starti, size_t endi)
+{
+    string x;
+    x.chars = &str.chars[starti];
+    x.length = (endi - starti);
+    return x;
+}
+
+string StringSlice_Length(string str, size_t starti, size_t length)
+{
+    string x;
+    x.chars = &str.chars[starti];
+    x.length = length;
+    return x;
+}

src/main.c

@@ -1,7 +1,45 @@
+#include "../include/lenstr.h"
+#include <string.h>
+#include <stdlib.h>
 #include <stdio.h>
 
-int main()
+int main(void)
 {
-    printf("hello world\n");
+    // C-style to string
+    string a;
+    a.chars = "Manual transformation of C-style to String";
+    a.length = strlen(a.chars);
+    PrintStr(a);
+
+    // Automatic c-style to string
+    string b = CStyleToLengthString_Assign("Function transformation of C-style to String");
+    PrintStr(b);
+
+    // String assigning (shallow copy) and copying (deep copy)
+    char xx[] = "String Assign Copy";
+    char yy[] = "String Deep Copy";
+    string x = CStyleToLengthString_Assign(xx);
+    string y = CStyleToLengthString_Assign(yy);
+    string c = x;
+    PrintStr(c);
+    string d = StringCopy(y);
+    PrintStr(d);
+    x.chars[3] = '!';
+    y.chars[3] = '!';
+    PrintStr(c);
+    PrintStr(d);
+
+    // Manual string slicing
+    string e;
+    e.chars = &a.chars[7];
+    e.length = 14;
+    PrintStr(e);
+
+    // Automatic string slicing (by length or by index range)
+    string f = StringSlice_Length(a, 7, 14);
+    string g = StringSlice_Index(a, 7, 21);
+    PrintStr(f);
+    PrintStr(g);
+
     return 0;
 }