EXPAND:  PROC(STRING,COMPRESS_CHAR);

/* THIS ROUTINE DECOMPRESSES A STRING BY EXPANDING PATTERNS OF COMPRESSION
   CHARACTERS DETECTED WHEN A COMPRESSION CHARACTER FOLLOWED BY A COUNT 
   IS FOUND. */

DCL STRING CHAR(*) VARYING;
DCL (I,J,K,LENGTH_STRING) FIXED BINARY(31);
DCL (COMPRESS_CHAR,TEST_CHAR) CHAR(1);
DCL OUT_STRING CHAR(LENGTH(STRING)*2) BASED(P);
DCL P POINTER;
ALLOC OUT_STRING SET(P);

LENGTH_STRING=LENGTH(STRING);
I=1;
J=1;

DO WHILE(I<=LENGTH_STRING);
  TEST_CHAR=SUBSTR(STRING,I,1);
  IF TEST_CHAR=COMPRESS_CHAR & I<LENGTH_STRING THEN DO;
    K=RANK(SUBSTR(STRING,I+1,1));
    SUBSTR(OUT_STRING,J,K)=COPY(COMPRESS_CHAR,K);
    J=J+K;
    I=I+2;    
  END;
  ELSE DO;
    SUBSTR(OUT_STRING,J,1)=TEST_CHAR;
    J=J+1;
    I=I+1;
  END;
END;

STRING=SUBSTR(OUT_STRING,1,J-1);
FREE OUT_STRING;
RETURN;

END EXPAND;