Re: Avoiding Booleans & Danny Thorpe

Brett Watters wrote: 
Andre,

[...]

1. NON-CONSTANT PARAMETERS

If the values aren't constants, the function is still unreadable.
  CreateFile(MyVariable,MyFunctionCall)

and you still can't tell what the parameter are without:
  CreateFile({New File} MyVariable, {Logging} MyFunctionCall)

Variables, properties, function calls, etc. all negate any advantage
for readability if the enumerated constant isn't visibile.

Why should they negate the advantage ? They don't have the advantage, that's true, since they don't have a single state which can be expressed by proper naming, but they must have a state assigned, where you will have an advantage.

And you can still can name the variables according to their function:

  CreateFile(newFileState, loggingState)


2. PARAMETERS BASED ON CONDITIONS

Compare
CreateFile( {New File} FileExists(MyFile), {Logging} not (FileDate(MyFile) > Date) )

and have to code it like: 
> [...]

              then CreateFile(cfaNewFile,cfaLogging)
              else CreateFile(cfaNewFile,cfaNoLogging)
       end
     else
       if not (FileDate(MyFile) > Date)
              then CreateFile(cfaExistingFile,cfaLogging)
              else CreateFile(cfaExistingFile,cfaNoLogging);

One line is always more readable than 6+. It is also far
less error prone.


I agree. But I don't have to code it with 6 lines that way.

    CreateFile( ShallFileBeCreated(MyFile),  LogginState());

function ShallFileBeCreated(FileName : string) : CreateType .....


And by the way. I wouldn't suggest enumeration types in any case. If they don't enhance readability in a single case don't use them.

3. BOOLEAN UNROLLING 

See above.


4. ENUMERATED TYPES AREN'T TRUE/FALSE
5. ENUMERATED TYPES AREN'T CLEAR EITHER

As I stated above use enumerations where they are appropriate and where they make code more readable. The rest is appropriate naming of variables. 

6. OTHER TYPES AREN'T SPELLED OUT FOR YOU
ANYWAY

If you use:
  Authorization("foo",AuthorizationCompletion.Pending)

then what is the "foo" parameter anyway? How about:
  Authorization("foo", 5, 0.245, AuthorizationCompletion.Finished)

i.e. you are going to have to look at Authorization to figure out
what it does or include:
   Authorization( {Caption} "foo", {Record No} 5, {Discount %} 0.245,
                          {Completion} AuthorizationCompletion.Finished )


It's not forbidden to combine comments and enumerations ;-).
But I would prefer something like:

Authorization( "foo",      // Caption
               5,          // Record No
               0.245,      // Discount
               Completion, // AuthorizationCompletion.Finished)


Thanks,
Brett


Thanks too ;-)
Andre
.