This array contains name of parser events.
This array contains name of scanner events.
This array contains name of all ripper events.
Ripper is a Ruby script parser.
You can get information from the parser with event-based style. Information such as abstract syntax trees or simple lexical analysis of the Ruby program.
Usage
Ripper provides an easy interface for parsing your program into a symbolic expression tree (or S-expression).
Understanding the output of the parser may come as a challenge, it's recommended you use PP to format the output for legibility.
require 'ripper'
require 'pp'
pp Ripper.sexp('def hello(world) "Hello, #{world}!"; end')
#=> [:program,
[[:def,
[:@ident, "hello", [1, 4]],
[:paren,
[:params, [[:@ident, "world", [1, 10]]], nil, nil, nil, nil, nil, nil]],
[:bodystmt,
[[:string_literal,
[:string_content,
[:@tstring_content, "Hello, ", [1, 18]],
[:string_embexpr, [[:var_ref, [:@ident, "world", [1, 27]]]]],
[:@tstring_content, "!", [1, 33]]]]],
nil,
nil,
nil]]]]You can see in the example above, the expression starts with
:program.
From here, a method definition at :def, followed by the
method's identifier :@ident. After the method's
identifier comes the parentheses :paren and the method
parameters under :params.
Next is the method body, starting at :bodystmt
(stmt meaning statement), which contains the full definition
of the method.
In our case, we're simply returning a String, so next we have the
:string_literal expression.
Within our :string_literal you'll notice two
@tstring_content, this is the literal part for Hello,
and !. Between the two @tstring_content
statements is a :string_embexpr, where embexpr is an
embedded expression. Our expression consists of a local variable, or
var_ref, with the identifier (@ident) of
world.
Resources
Requirements
-
ruby 1.9 (support CVS HEAD only)
-
bison 1.28 or later (Other yaccs do not work)
License
Ruby License.
Minero Aoki
aamine@loveruby.net
http://i.loveruby.net