Proposal for a new operator - .=

ruby-talk
1

OK so it’s late, I’m not thinking straight, and I thought I’d post
this.

Proposal for a new operator - .=

···

================================

Ruby has a number of useful operators, including some for combined
operation/assignment, such as +=, -=, etc.

This proposal is for a new operation/assignment operator, .=
(period-equals). Existing operators follow this form:

a += b      # =>   a = a + b
a -= b      # =>   a = a - b

The proposed .= operator would follow in an identical fashion:

a .= b      # =>   a = a.b

For instance, some practical applications:

# We're passed an object, we want to do work on it
def foo(x)
   x .= dup
   :
end

# We have an operation for which there is no bang! method:
hash .= invert

# Similar to the last, we have an object which a bang method
# is impossible:
i  = 5 
i .= succ  # => 6

# Following from that, we can't really change what an object _is_,
# but with .= we don't need to:
c  = 65
c .= chr   # => "A"

This has the following important advantages:

*  It provides a generic operation/assignment operator

*  Much like existing operation/assignment operators, it saves
   space and increases readability

*  It confuses Perl programmers

Support this new operator for Ruby!

(The preceding was 90% a joke. I don’t actually have any serious
expectation of a .= operator in Ruby. I imagine it would be a bit
hairy to implement. I actually thought of it after doing "s = s.dup"
a few times, and there may be a few good uses for it, but… this was
for entertainment purposes only. :wink:

–
Ryan Pavlik rpav@mephle.com

“Every day shall be sword day.” - 8BT

2

“Ryan Pavlik” rpav@mephle.com schrieb im Newsbeitrag
news:20031117020352.788607da.rpav@mephle.com…

···

OK so it’s late, I’m not thinking straight, and I thought I’d post
this.

Proposal for a new operator - .=

Ruby has a number of useful operators, including some for combined
operation/assignment, such as +=, -=, etc.

This proposal is for a new operation/assignment operator, .=
(period-equals). Existing operators follow this form:

a += b      # =>   a = a + b
a -= b      # =>   a = a - b

The proposed .= operator would follow in an identical fashion:

a .= b      # =>   a = a.b

For instance, some practical applications:

# We're passed an object, we want to do work on it
def foo(x)
   x .= dup
   :
end

# We have an operation for which there is no bang! method:
hash .= invert

# Similar to the last, we have an object which a bang method
# is impossible:
i  = 5
i .= succ  # => 6

# Following from that, we can't really change what an object _is_,
# but with .= we don't need to:
c  = 65
c .= chr   # => "A"

This has the following important advantages:

*  It provides a generic operation/assignment operator

*  Much like existing operation/assignment operators, it saves
   space and increases readability

*  It confuses Perl programmers

Support this new operator for Ruby!

(The preceding was 90% a joke. I don’t actually have any serious
expectation of a .= operator in Ruby. I imagine it would be a bit
hairy to implement. I actually thought of it after doing “s = s.dup”
a few times, and there may be a few good uses for it, but… this was
for entertainment purposes only. :wink:

:-))

This becomse more interesting with multiple method invocations:

foo = foo.bar.baz # becometh
foo .= bar.baz

foo.bar = foo.bar.baz # now is
foo.bar .= baz

Weired…

robert