DEFINITION MODULE Strings;
(* Bounded string operations over descriptor strings (classic
   Modula-2 form). Sources are [0..] indexed; destinations are
   truncated to fit (never overrun). *)

PROCEDURE Length(VAR s : ARRAY OF CHAR) : INTEGER;
(* Number of characters in s. *)

PROCEDURE Assign(VAR src, dst : ARRAY OF CHAR);
(* Copies src into dst (truncated to dst's capacity). *)

PROCEDURE Concat(VAR s1, s2 : ARRAY OF CHAR; VAR dst : ARRAY OF CHAR);
(* dst := s1 followed by s2 (truncated to fit). *)

PROCEDURE Compare(VAR s1, s2 : ARRAY OF CHAR) : INTEGER;
(* <0, 0 or >0 as s1 is less than, equal to, or greater than s2. *)

PROCEDURE Copy(VAR src, dst : ARRAY OF CHAR);
(* Alias for Assign, ISO-style name. *)

END Strings.