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Feature #17769

closed

Proposal: numeric coefficient syntax

Status:
Rejected
Assignee:
-
Target version:
-
[ruby-core:103140]
Tags:

Description

When we write a mathematical equation, we often omit a multiplication operator between a coefficient and a variable like `2x`.
I guess this convention can be useful in computer programming. Practically, Julia employs this notation:

``````julia> 2pi
6.283185307179586

julia> x = 3
3

julia> 2x
6

julia> pi
π = 3.1415926535897...

julia> 2pi
6.283185307179586
``````

I wrote a proof-of-concept patch to introduce this notation in Ruby.
We can write the following with this patch:

``````irb(main):001:0> x = 3
=> 3
irb(main):002:0> 2x
=> 6
irb(main):003:0> def pi = Math::PI
=> :pi
irb(main):004:0> 2pi
=> 6.283185307179586
``````

Files

Actions #1

Updated by mame (Yusuke Endoh)about 3 years ago

• Tags set to joke

Updated by matz (Yukihiro Matsumoto)about 3 years ago

``````i = 10
p 2i # => 20 or Complex(0,2)?
``````

Matz.

Updated by mrkn (Kenta Murata)about 3 years ago

`2i` is an imaginary number literal so it is `Complex(0, 2)`.

Actions #4

Updated by mrkn (Kenta Murata)about 3 years ago

• File deleted (num_coeff.patch)

Updated by mrkn (Kenta Murata)about 3 years ago

I replaced the attached patch with changes to accept not only `2x` but also `2(x + 1)`.

Updated by mrkn (Kenta Murata)about 3 years ago

Replace the patch with refactoring.

Actions #7

Updated by mrkn (Kenta Murata)about 3 years ago

• File deleted (num_coeff.patch)
Actions #8

Updated by mrkn (Kenta Murata)about 3 years ago

• Status changed from Open to Rejected
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