🚀 go-pugleaf

/////

> program ReadTest(input,output);
>   var C: char;
>   begin
>     repeat
>       while not eoln do begin	(* should echo one line of chars *)
>         read(C);   write(C);
>       end;
>       readln(C);	(* supposed to be required to read past *)
>       writeln;		(* end-of-line marker, right ???        *)
>     until eof;
>   end.
>   
> 	This program seems to work fine when you are reading from the 
> standard input, but if you redirect input from a file, every other line
> is skipped.

The Pascal procedure to advance to the next line is "Readln", with no
parameter.  "Readln(C)" is equivalent to "Read(C); Readln", which in
turn is equivalent to "C:=Input^; Get(Input); Readln(Input)".  This
assigns the space character to C (Input^ = ' ' when Eoln(Input) is true).
The Get advances over the end-of-line condition (Get will advance to the
next line, just like Readln, when Eoln is true).  And finally, the Readln
advances to the NEXT line.  Presto -- you just skipped over an input line.
So, it's not a compiler bug.

	-Neil Faiman

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