Using each_slice possible?

Frankn

I have a feeling this is a stupid question but I can't find the answer!

I need to use each_slice in a plugin I'm working on but can't get it to work... I keep getting Error: #<NoMethodError: undefined method `each_slice' for #Array:0xc6c8c14>.

Thanks in advance!

Frank

Frankn

Thanks Dan!
But I get this error now...
Error: #<NoMethodError: undefined method `abs' for Math:Module>

Dan Rathbun

@frankn said:

But I get this error now...
Error: #<NoMethodError: undefined method `abs' for Math:Module>

Fixed absolute call (in example above.)

It is not a Math module function. It is a standard Ruby Numeric instance method.

I just assumed the Math module would have an "abs" function.

The absolute call is to prevent an Index error:
ary.slice!(0,-3) %(#004000)[Error: #<IndexError: (eval):0:inslice!': negative length (-3)>]`

Frankn

Thanks Dan that works awesome!

Now I'm having the same problem with delete_if! Isn't there an addon or file we can download to get the missing methods? If not how do you know figure out how to make new ones as you did? I don't want to have to bother anyone the next time I get a similar error if I can fix it myself.

Dan Rathbun

@frankn said:

Now I'm having the same problem with "delete_if!"

That is because the method's name is delete_if.

There is no exclamation point name.

You should refer to the documentation for Ruby v1.8.6 when programming for Ruby v1.8.6.
RUBY PROGRAMMING REFERENCES

Frankn

@dan rathbun said:

@frankn said:

Now I'm having the same problem with "delete_if!"

That is because the method's name is delete_if.

There is no exclamation point name.

I was actually using the ! as punctuation not in my code.

BUT reading your post made me realize I had made typo somewhere else in my code causing the error.

Thanks again for your help sir.

Dan Rathbun

@frankn said:

Isn't there an addon or file we can download to get the missing methods?

There may be a "Backport" gem for Ruby v1.8.6 that adds later methods.

But you would need to convince all users to install it. It also may not have ALL the new methods in later versions (such as v1.9.x or v2.0.x.)

@frankn said:

If not how do you know figure out how to make new ones as you did?

I do not know how to answer that. Many many years experience.

Read as many books on Ruby as you can.

Keeping trying and failing, until you gain success ?

Dan Rathbun

Here is another edition that will collect the slices into an output array, IF a block is NOT given. (Sort of like the opposite to flatten().)

If a block is given, it returns an array of the block's return values.

Prints to $stdout only if $VERBOSE == true.

def slicer(ary,num)
  a2 = ary.dup
  len = num.to_i.abs
  out = []
  until (s = a2.slice!(0,len)).empty?
    puts(s.inspect) if $VERBOSE
    if block_given?
      out << yield(s)
      puts( out.last.inspect ) if $VERBOSE
    else
      out << s
    end
  end # until
  return out
end # slicer()

EDIT: fixed puts'ing block results

Dan Rathbun

EDIT: fixed puts'ing block results in the 2nd example.

Dan Rathbun

You get a NoMethodError because Enumerable does not have that method defined in Ruby 1.8.x.

This should do the same, except you pass the array in as the 1st argument:

def slicer(ary,num)
  a2 = ary.dup
  len = num.to_i.abs
  until (s = a2.slice!(0,len)).empty?
    if block_given?
      yield(s) 
    else
      puts(s.inspect)
    end
  end # until
end # slicer()

See another example that will collect the slices into an output array, IF a block is NOT given. (Sort of like the opposite to flatten().) If a block is given, it returns an array of the block's return values. Prints to $stdout only if $VERBOSE == true.

Fixed absolute call. It is not a Math module function. It is a standard Ruby Numeric instance method.