ISO Pascal reference manual

PROGRAM fail;
VAR p : PACKED ARRAY C1..5] OF char;
u : ARRAY [2..6] OF Boolean;
BEGIN
pack(u, 2, p); [boolean can't be assigned to char}
END.
*ERROR 142-- the type of this expression is not suitable as an
index into the unpacked array
This error indicates an attempt to use a value of an unsuitable type to index
the unpacked array in a PACK or UNPACK statement.
PROGRAM fail;
TYPE t1 = (a, b, c, d);
t2 = 0..3;
VAR p : PACKED ARRAY [t1] OF char;
u : ARRAY [t2] OF char;
BEGIN
pack(u, a, p); (a is not of type t2}
unpack(p, u, a); (ditto}
END.
*ERROR 143 -- this string contains more than 255 characters
The compiler limits the maximum number of characters in a string constant
to 255. It is unlikely that this message will ever be generated as it takes a
fair degree of effort to generate a source file containing such a constant
(which is why no sample program is given here).
*ERROR 144 -- string constants must contain at least two characters
This error is caused by a string or character constant which contains no
characters, i.e. two consecutive quotes. The Pascal standard states that one
character between quotes is a constant of type CHAR and that string
constants must have two or more characters in them.
PROGRAM fail(output);
BEGIN
writeln("); {" is a null string}
END.
96 Pascal Issue I