Slides by Jakub Naliwajek, Ruby on Rails developer at @netguru for SPARKcamp#5 meet-up.

1. DSLdomain-specific language
@ SPARKcamp #5
(in Ruby)

2. jakub naliwajek

3. netguru.co

4. DSLdomain-specific language

5. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.

6. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL

7. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL

8. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL

9. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL

10. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL

11. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL
Simpler DSLs,
particularly ones
used by a single
application, are
sometimes
informally called
mini-languages.

12. DSLdomain-specific language
A domain-specific
language (DSL) is a
computer language
specialized to a
particular application
domain.
•Perl
•HTML
•MATLAB
•VHDL
•SQL
Simpler DSLs,
particularly ones
used by a single
application, are
sometimes
informally called
mini-languages
INTERNAL.

13. LISP

14. LISP
1958

15. LISP
1958

16. “On Lisp” – Paul Graham
Add “for” loop to LISP

17. RUBY

20. RUBYon rails

21. Rails “Migrations” DSL

22. RSpec DSL (testing framework)

23. DSLis not
for
COMPUTERS

24. describe == context == it
(for computers)

25. PROBLEM

28. survey(name, &block)

29. survey(name, &block)

30. survey(name, &block)

31. survey(name, &block)

32. survey(name, &block)
question(content, **params, &block)

33. survey(name, &block)
question(content, **params, &block)

34. survey(name, &block)
question(content, **params, &block)

35. survey(name, &block)
question(content, **params, &block)

36. survey(name, &block)
question(content, **params, &block)

37. survey(name, &block)
question(content, **params, &block)
answer(content)

38. survey(name, &block)
question(content, **params, &block)
answer(content)

39. WHAT
HELPS?

41. META
PROGRAMMING

43. BLOCKS

45. 0
20
40
60
80
no DSL DSL
use
uselearn
learn
How DIFFICULT?

47. 0
20
40
60
80
no DSL DSL
use
uselearn
learn
How DIFFICULT?

48. Which one is more readable?
MiniTest RSpec

49. NOT
ALWAYS
COOL

51. developers […] who cannot survive without frameworks.
– Adam Hawkins
http://hawkins.io/2015/05/the-ruby-community-the-next-version/

53. simplicity over
convenience
=
good for
long-term

54. how many lines will
that DSL save?

55. thoughtbot/factory_girl
(kinda nice example)

56. thanks
netguru.co/signup/sparkcamp