Clean Code

Listing 14-12 (continued)
Args.java (After first refactoring)

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231
String Arguments
After all that work, this is a bit disappointing. The structure is a bit better, but we still
have all those variables up at the top; there’s still a horrible type-case in 
setArgument
; and
all those 
set
functions are really ugly. Not to mention all the error processing. We still
have a lot of work ahead of us.
I’d really like to get rid of that type-case up in 
setArgument
[G23]. What I’d like in
setArgument
is a single call to 
ArgumentMarshaler.set
. This means I need to push
setIntArg
,
setStringArg
, and 
setBooleanArg
down into the appropriate 
ArgumentMarshaler
derivatives. But there is a problem.
If you look closely at 
setIntArg
, you’ll notice that it uses two instance variables: 
args
and
currentArg
. To move 
setIntArg
down into 
BooleanArgumentMarshaler
, I’ll have to pass
both
args
and
currentArgs
as function arguments. That’s dirty [F1]. I’d rather pass one
argument instead of two. Fortunately, there is a simple solution. We can convert the 
args
array into a 
list
and pass an 
Iterator
down to the 
set
functions. The following took me
ten steps, passing all the tests after each. But I’ll just show you the result. You should be
able to figure out what most of the tiny little steps were.
public class Args {
private String schema;
private String[] args;
private boolean valid = true;
private Set unexpectedArguments = new TreeSet();
private Map marshalers = 
new HashMap();
private Set argsFound = new HashSet();
private