Download Parsing Ruby (reloaded)

Parsing Ruby
Rathesan Iyadurai
1
Goal
Extract all classes and their methods
without having to define the complete
grammar of Ruby.
2
Previously on “Parsing
Ruby”
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
4
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
5
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
6
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
7
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
8
'foo class bar'
"foo class bar"
%?foo class bar?
%{foo class bar}
%<foo class bar>
%(foo class bar)
%[foo class bar]
%q{foo class bar}
%Q{foo class bar}
<<spongebob.strip
foo class bar
spongebob
9
Modifiers
10
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
11
class Dog
class Dog
attr_accessor :age
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
@name = "foo class bar"
@age = age
end
def bark
str = if age > 3
"wuff"
else
"wiff"
end
puts str
end
def bark
if age > 3
puts "wuff"
else
puts "wiff"
end
end
end
end
12
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
@name = "foo class bar"
@age = age
end
def bark
str = if age > 3
"wuff"
else
"wiff"
end
puts str
end
end
13
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
modifier :=
startOfLine ,
stuffToConsume ,
newline not ,
'=' not ,
'if'
@name = "foo class bar"
@age = age
end
def bark
str = if age > 3
"wuff"
else
"wiff"
end
puts str
end
end
14
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
modifier :=
startOfLine ,
stuffToConsume ,
newline not ,
'=' not ,
'if'
@name = "foo class bar"
@age = age
end
def bark
str = if age > 3
"wuff"
else
"wiff"
end
puts str
end
end
15
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
modifier :=
startOfLine ,
stuffToConsume ,
newline not ,
'=' not ,
'if'
@name = "foo class bar"
@age = age
end
def bark
str = if age > 3
"wuff"
else
"wiff"
end
puts str
end
end
16
class Dog
attr_accessor :age
def initialize(age)
raise "NOO" if age < 1
modifier :=
startOfLine ,
stuffToConsume ,
newline not ,
'=' not ,
'if'
@name = "foo class bar"
@age = age
end
def bark
str = if age > 3
"wuff"
else
"wiff"
end
puts str
end
end
17
~ 50 rules
10 for matching “end”s
13 for keywords
10 for strings and comments
18
Keywords
def if
endless
bado
end.class
19
Keywords
def if
endless
bado
end.class
20
String Interpolation
name = "Jan"
"Hi #{name}!" # => "Hi Jan!"
"Hi #{class Dog; end}"
"Hi #{puts ""}"
"Hi #{list.each { |l| foo }}"
21
vs
https://github.com/jruby/jruby-parser
22
class Dog
end if foo?
23
Now what?
24
def foo
a = "i'm a local variable!"
b
end
def b
"i'm a method!"
end
25
def foo(arg)
a = "i'm a local variable!"
arg.b
end
26
Overview
Goal: Extract all classes and their methods without
having to define the complete grammar of Ruby
Problems: modifiers, keywords, string interpolation
Goal achieved?
27
RubyGrammar Performance
3000
smooth milliseconds per character count
2500
Milliseconds
2000
1500
1000
500
0
0
5000
10000
15000
20000
25000
Number of Characters
30000
35000
40000
45000
RubyGrammar Performance
3000
smooth milliseconds per method count
2500
Milliseconds
2000
1500
1000
500
0
0
20
40
60
Number of Methods
80
100
120