To expand on this:
user=> (defn try [] 5)
#'user/try
user=> (try) ; `try` alone is resolved to the special form
nil
user=> (#'try) ; obtaining the `try` var works just fine
; (vars currently delegate function calls to their values)
5
user=> (@#'try) ; explicitly deref'ing the fn from the `try` var and invoking it
5
So, you *can* shadow the binding of try (or any special form) within a given
namespace, but you also need to resolve the var in question yourself (since
regular symbols naming special forms are always given priority without the #'
syntax [or use of the `var` macro]). None of that is required for regular
functions, the resolution of which always takes into account the current
namespace and its interned/referred vars.
- Chas
On Jan 10, 2011, at 8:51 PM, Stuart Halloway wrote:
> Hi Tom,
>
> "try" is a special form, and "test" is a function.
>
> Stu
>
>> I know I should not be naming my functions the same thing as ones in
>> core but was surprised when I wrote the following
>> https://github.com/thattommyhall/tth-SICP/blob/master/1-35.clj
>> I have being doing the SICP stuff in clojure and accieently copied
>> "try" as the fn name and it did not work, I noticed a colleague chose
>> "test" and it did work, but test is in core too so I don't get the
>> difference.
>>
>> Playing around on the repl I get
>> user> (defn try [] ())
>> #'user/try
>> user> (defn test [] ())
>> WARNING: test already refers to: #'clojure.core/test in namespace:
>> user, being replaced by: #'user/test
>> #'user/test
>> user> (try 1)
>> 1
>> user> (test 1)
>> Throws "Wrong number of args (1) passed to: user$test" (as you would
>> expect from my defn of test)
>>
>> user> (user/try 1)
>> and
>> user> (user/test 1)
>> both
>> throw the error.
>>
>>
>> Why can test be shadowed and not try? Am I missing something?
>>
>> Tom
>>
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