parsing ruby reloaded - scg.unibe.chscg.unibe.ch/...03-23-iyadurai-parsingrubyreloaded.pdf · raise...
TRANSCRIPT
Parsing Ruby
Rathesan Iyadurai
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Goal
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Extract all classes and their methods without having to define the complete
grammar of Ruby.
Previously on “Parsing Ruby”
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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
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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
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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
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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
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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
'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
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Modifiers
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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
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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
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
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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
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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
modifier := startOfLine , stuffToConsume , newline not , '=' not , 'if'
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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
modifier := startOfLine , stuffToConsume , newline not , '=' not , 'if'
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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
modifier := startOfLine , stuffToConsume , newline not , '=' not , 'if'
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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
modifier := startOfLine , stuffToConsume , newline not , '=' not , 'if'
~ 50 rules
10 for matching “end”s
13 for keywords
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10 for strings and comments
Keywords
def if endless bado end.class
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Keywords
def if endless bado end.class
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String Interpolationname = "Jan" "Hi #{name}!" # => "Hi Jan!"
"Hi #{class Dog; end}"
"Hi #{puts ""}"
"Hi #{list.each { |l| foo }}"
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class Dog end if foo?
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Now what?
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def foo a = "i'm a local variable!" b end
def b "i'm a method!" end
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def foo(arg) a = "i'm a local variable!" arg.b end
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Overview
Goal: Extract all classes and their methods without having to define the complete grammar of Ruby
Problems: modifiers, keywords, string interpolation
Goal achieved?
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Number of Characters
RubyGrammar Performance
smooth milliseconds per character count
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Number of Methods
RubyGrammar Performance
smooth milliseconds per method count