Issue #14151 has been updated by greggzst (Grzegorz Jakubiak).


marcandre (Marc-Andre Lafortune) wrote:
> The method []= as it is written is also dangerous as it doesn't do any type checking. Try calling `m[1..2, 1..2] = 42` for example...

@marcandre I called it using send and it didn't change a thing in my 3x3 Matrix. So what you probably mean we'd have to add this functionality so it works as in arrays when you pass a range.

My example (at the end I'm setting one element) :

~~~ ruby
 m = Matrix[[1,2,3],[1,2,3],[1,2,3]]
 => Matrix[[1, 2, 3], [1, 2, 3], [1, 2, 3]] 
 m.send(:[]=, 1..2, 1..2, 5)
 => 5 
 m
 => Matrix[[1, 2, 3], [1, 2, 3], [1, 2, 3]] 
 m.send(:set_element, 1..2, 1..2, 5)
 => 5 
 m
 => Matrix[[1, 2, 3], [1, 2, 3], [1, 2, 3]] 
 m.send(:[]=, 1, 1, 5)
 => 5 
 m
 => Matrix[[1, 2, 3], [1, 5, 3], [1, 2, 3]] 
~~~




----------------------------------------
Feature #14151: Make Matrix#[]= public method
https://bugs.ruby-lang.org/issues/14151#change-68264

* Author: greggzst (Grzegorz Jakubiak)
* Status: Feedback
* Priority: Normal
* Assignee: marcandre (Marc-Andre Lafortune)
* Target version: 
----------------------------------------
I don't even understand why this method hasn't been public since the beginning. I've come to a point when I have to create a matrix in a specific way using row and column indices and I can't use #build with a block because then indices go from the beginning of matrix whereas I have to from the center of the matrix. So what I wanted to do is to create a zero matrix and the fill it in a proper way but I can't without using #[]=. I know I can reopen class and that's what I'm doing but this just doesn't make sense. If we can change elements in an array like so using #[]= then why matrices can't use that as well?



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