Re: Form feed comment for pragma Page

[dewar@cs.nyu.edu (Robert Dewar)]

Art says

"Well, form feed (control-L) is an ASCII character and part of the
standard character set, but I'm quite surprised to hear that it's a
logical-end-of line, for two reasons:

  - If anything, it's-end-of page, not-end-of line.

  - And it's not even that.  The RM in A.10(8) is quite clear that the
    standard does not specify which characters, if any, correspond to
    logical end-of-line or end-of-page or end-of-file.

I'll agree that many implementations, probably most of them, choose to
implement end-of-page using the ASCII form feed character, but the
standard is silent on the subject."

Art, you are confused, we are talking about source representation here.
YOu quoted some irrelevant paragraph about Text_IO. THe operable
statement in the standard is:

2.1
13  format_effector
                The control functions of ISO 6429 called character tabulation
                (HT), line tabulation (VT), carriage return (CR), line feed
                (LF), and form feed (FF).

and

2.2
2   The text of a compilation is divided into lines.  In general, the
representation for an end of line is implementation defined.  However, a
sequence of one or more format_effectors other than character tabulation (HT)
signifies at least one end of line.

Pretty clear, and far from silent.

It is very important to understand that source representation has nothing
to do with type Standard.Character or with Text_IO. Sure, may implementations
may choose to represent the source in a manner that is consistent with
Text_IO as a sequence of elements of type Standard.Character, but this is
not a required representation, just one possible choice.