On 02/02/2016 13:24, Sven Barth wrote:
> Look at the "iif" as an statement and the things will be simple.
BECAUSE. IT. IS. *NOT*. A. STATEMENT!
It never was and it never will be! It returns a value and thus by
definition it is an expression!
+1
And imho that why it is important that it does not look like a statement
either, i.e. it does not start with a keyword.
also if we are discussing (are we?) a form like
x:= iIf a>b iThen c iElse b;
then why not
x:= a>b ifThen c ifElse b;
What are the advantages/disadvantages they have over each other?
They both need operator precedence:
x := iIf a Then b else c + 3;
should be which
x := (iIf a Then b else c) + 3;
x := iIf a Then b else (c + 3);
unless a closing "end" is enforced
x:= iIf a>b iThen c iElse b iEnd;
Which is what the function stile does implicitly, by having brackets
around all 3 arguments.
------------------
Btw, just for fun, did some playing to see how much could be done with
current fpc
program Project1;
{$mode objfpc}
{$MACRO on}
{$define ifthen:=and}
{$define ifelse:=or}
type TIfThen = record
b:boolean;
v:integer;
end;
operator and (a:boolean;b:integer):TIfThen;
begin
result.b := a;
result.v := b;
end;
operator or (a:TIfThen;b:integer):integer;
begin
if a.b then
result := a.v
else
result := b;
end;
begin
writeln( (1<2) and 3 or 4 );
writeln( (1>2) and 3 or 4 );
writeln( (1<2) ifthen 3 ifelse 4 );
writeln( (1>2) ifthen 3 ifelse 4 );
readln;
end.
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