Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Immutability and Design Patterns in Ruby   Functional Programming has seen a resurgence in interest in the last few
years and is often mentioned in opposition to Object-Orientated Programming.
However, Object-Orientated Programming can actually absorb some of the lessons
of Functional Programming to improve performance and reliability. This paper
examines three ways in which Immutability, a common Functional Programming
technique, can be used to develop immutable objects in Ruby.

11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph