Standard library improvements

docs/stdlib/string.md

@@ -0,0 +1,25 @@
+[< back to index](../index.md)
+
+## string
+
+The `string` module automatically imports the `err` module.  
+
+#### `byte strzlen(pointer str)`
+
+Calculates the length of a null-terminated string.  
+If the string is longer than 255 bytes, then the behaviour is undefined (might even crash).
+
+#### `sbyte strzcmp(pointer str1, pointer str2)`
+
+Compares two strings. Returns 0 if equal, non-0 if not equal.
+If any of the strings is longer than 255 bytes, then the behaviour is undefined (might even crash).
+
+#### `void strzcopy(pointer dest, pointer src)`
+
+Copies the source null-terminated string into the destination buffer.
+If the source string is longer than 255 bytes, then the behaviour is undefined (might even crash).
+
+#### `word strz2word(pointer str)`
+
+Converts a null-terminated string to a number.
+Sets `errno`.