Proc#curry doesn't always detect too many arguments
Currently, Proc#curry checks the validity of the
arity argument and will raise an error if:
1) arity is less than the number of required arguments or
2) arity is more than the maximum number of arguments
Note that simple Procs always accept any number of arguments (even though they may be ignored), so (2) doesn't applies to them, only to lambda's and procs made from methods.
#2 isn't done as well as it could in case of limited optional parameters:
def Object.foo(a, b=42); end def Object.bar(a, b); end Object.method(:foo).to_proc.curry(3) # => curried proc which will raise an error only when passed it's 3rd parameter Object.method(:bar).to_proc.curry(3) # => ArgumentError: wrong number of arguments (3 for 2) Same thing with lambdas
My proposed fix passes SST:
a) usefulness: "fail-early" principle [ruby-core:24130]
b) consistency: both methods can only accept a maximum of 2 parameters and are thus treated consistently when attempting to curry with more than 2 arguments
c) intuitiveness and d) performance: similar
It is straightforward (but not obvious), as it passes NIT (but not ODT).
Updated by marcandre (Marc-Andre Lafortune) about 8 years ago
Koichi Sasada wrote:
Any progress on it?
I'm having some problems running all tests, but here is what I've done so far.
The first patches defines various
min_max_arity functions to get min and max number of (non-ignored) arguments of Proc/Lambdas/Methods. It would make the addition of Ruby methods
Note that to know the maximum arity for most builtin methods would require an extensive refactoring.
The second patch fixes
Proc#curry (again, except for most builtin methods). This uses both the first patch and the patches of issue #6089.
Updated by marcandre (Marc-Andre Lafortune) about 7 years ago
- Status changed from Assigned to Closed
- % Done changed from 0 to 100
This issue was solved with changeset r39008.
Marc-Andre, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.
proc.c (proc_curry): Fix arity check [Bug #5747]
test/ruby/test_proc.rb: Test for above