[comp.lang.modula2] Character Assign/Read to Cardinal

meyer@unix.cis.pitt.edu (Timothy S. Meyer) (04/05/91)

A colleague of mine has a concern with a Modula-2 implementation he is using.
I had no ready answer to a question--can anyone help?

It seems that the compiler will not allow an assignment statement which assigns
a character type to a cardinal type.  But, during run-time, a character is
an acceptable input when reading a cardinal.  Is this the way it is supposed
to be?

I haven't kept up with this newsgroup--sorry if this is a repeat.

seurer+@rchland.ibm.com (Bill Seurer) (04/06/91)

No, that shouldn't be acceptable.  Sounds like he is using JPI.  It does
really strange things if you try to enter a non-numeric character when
it is reading a number.

The solution is to read everything as character strings and then use the
string conversion functions to convert to whatever it is you expected to
read.  They usually have some sort of error flag so you can detect when
bad data was typed.

- Bill Seurer      IBM: seurer@rchland  Prodigy: CNSX71A
  Rochester, MN    Internet: seurer@rchland.vnet.ibm.com