defining dsl (domain specific language) using ruby
TRANSCRIPT
DSLdomain-specific language
@ SPARKcamp #5
(in Ruby)
jakub naliwajek
DSLdomain-specific language
DSLdomain-specific language
A domain-specific language (DSL) is a computer language specialized to a particular application domain.
DSLdomain-specific language
A domain-specific language (DSL) is a computer language specialized to a particular application domain.
•Perl •HTML •MATLAB •VHDL •SQL
DSLdomain-specific language
A domain-specific language (DSL) is a computer language specialized to a particular application domain.
•Perl •HTML •MATLAB •VHDL •SQL
DSLdomain-specific language
A domain-specific language (DSL) is a computer language specialized to a particular application domain.
•Perl •HTML •MATLAB •VHDL •SQL
DSLdomain-specific language
A domain-specific language (DSL) is a computer language specialized to a particular application domain.
•Perl •HTML •MATLAB •VHDL •SQL
DSLdomain-specific language
A domain-specific language (DSL) is a computer language specialized to a particular application domain.
•Perl •HTML •MATLAB •VHDL •SQL
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.
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.
LISP
LISP1958
LISP1958
“On Lisp” – Paul Graham
Add “for” loop to LISP
RUBY
RUBYon rails
Rails “Migrations” DSL
RSpec DSL (testing framework)
DSLis not for COMPUTERS
describe == context == it(for computers)
PROBLEM
survey(name, &block)
survey(name, &block)
survey(name, &block)
survey(name, &block)
survey(name, &block)
question(content, **params, &block)
survey(name, &block)
question(content, **params, &block)
survey(name, &block)
question(content, **params, &block)
survey(name, &block)
question(content, **params, &block)
survey(name, &block)
question(content, **params, &block)
survey(name, &block)
question(content, **params, &block)
answer(content)
survey(name, &block)
question(content, **params, &block)
answer(content)
WHAT HELPS?
META PROGRAMMING
BLOCKS
0
20
40
60
80
no DSL DSL
use
uselearn
learn
How DIFFICULT?
0
20
40
60
80
no DSL DSL
use
uselearn
learn
How DIFFICULT?
Which one is more readable?
MiniTest RSpec
NOT ALWAYS COOL
developers […] who cannot survive without frameworks. – Adam Hawkins
http://hawkins.io/2015/05/the-ruby-community-the-next-version/
simplicity over convenience
= good for long-term
how many lines will that DSL save?
thoughtbot/factory_girl(kinda nice example)
