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Class: Ripper

Relationships & Source Files
Namespace Children
Classes:
Filter, Lexer, SexpBuilder, SexpBuilderPP, TokenPattern
Extension / Inclusion / Inheritance Descendants
Subclasses:
Lexer, SexpBuilder, SexpBuilderPP
Inherits: Object
Defined in: ext/ripper/lib/ripper.rb,
parse.y,
ext/ripper/lib/ripper/core.rb,
ext/ripper/lib/ripper/filter.rb,
ext/ripper/lib/ripper/lexer.rb,
ext/ripper/lib/ripper/sexp.rb

Overview

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.

Constant Summary

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(src, filename = "(ripper)", lineno = 1) ⇒ Ripper

Create a new Ripper object. src must be a String, an IO, or an ::Object which has #gets method.

This method does not starts parsing. See also #parse and .parse.

[ GitHub ] 

  


# File 'parse.y', line 11345



static VALUE
ripper_initialize(int argc, VALUE *argv, VALUE self)
{
    struct parser_params *p;
    VALUE src, fname, lineno;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    rb_scan_args(argc, argv, "12", &src, &fname, &lineno);
    if (RB_TYPE_P(src, T_FILE)) {
        p->lex.gets = ripper_lex_io_get;
    }
    else if (rb_respond_to(src, id_gets)) {
        p->lex.gets = ripper_lex_get_generic;
    }
    else {
        StringValue(src);
        p->lex.gets = lex_get_str;
    }
    p->lex.input = src;
    p->eofp = 0;
    if (NIL_P(fname)) {
        fname = STR_NEW2("(ripper)");
	OBJ_FREEZE(fname);
    }
    else {
	StringValueCStr(fname);
	fname = rb_str_new_frozen(fname);
    }
    parser_initialize(p);

    p->ruby_sourcefile_string = fname;
    p->ruby_sourcefile = RSTRING_PTR(fname);
    p->ruby_sourceline = NIL_P(lineno) ? 0 : NUM2INT(lineno) - 1;

    return Qnil;
}


  







Class Method Details



  

    #dedent_string(input, width)  ⇒ Integer  (private)    Also known as: #dedent_string
  



  

    

USE OF RIPPER LIBRARY ONLY.



Strips up to width leading whitespaces from input, and returns the stripped column width.


  



  [ GitHub ]


  

  


# File 'parse.y', line 6224



static VALUE
parser_dedent_string(VALUE self, VALUE input, VALUE width)
{
    int wid, col;

    StringValue(input);
    wid = NUM2UINT(width);
    col = dedent_string(input, wid);
    return INT2NUM(col);
}


  








  

    .lex(src, filename = '-', lineno = 1)  
  



  

    

Tokenizes the Ruby program and returns an array of an array, which is formatted like [[lineno, column], type, token, state].



require 'ripper'
require 'pp'

pp Ripper.lex("def m(a) nil end")
#=> [[[1,  0], :on_kw,     "def", Ripper::EXPR_FNAME                   ],
     [[1,  3], :on_sp,     " ",   Ripper::EXPR_FNAME                   ],
     [[1,  4], :on_ident,  "m",   Ripper::EXPR_ENDFN                   ],
     [[1,  5], :on_lparen, "(",   Ripper::EXPR_LABEL | Ripper::EXPR_BEG],
     [[1,  6], :on_ident,  "a",   Ripper::EXPR_ARG                     ],
     [[1,  7], :on_rparen, ")",   Ripper::EXPR_ENDFN                   ],
     [[1,  8], :on_sp,     " ",   Ripper::EXPR_BEG                     ],
     [[1,  9], :on_kw,     "nil", Ripper::EXPR_END                     ],
     [[1, 12], :on_sp,     " ",   Ripper::EXPR_END                     ],
     [[1, 13], :on_kw,     "end", Ripper::EXPR_END                     ]]


  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/lexer.rb', line 44



def Ripper.lex(src, filename = '-', lineno = 1)
  Lexer.new(src, filename, lineno).lex
end


  








  

    .lex_state_name(integer)  ⇒ String   



  

    

Returns a string representation of lex_state.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11538



static VALUE
ripper_lex_state_name(VALUE self, VALUE state)
{
    return rb_parser_lex_state_name(NUM2INT(state));
}


  








  

    .parse(src, filename = '(ripper)', lineno = 1)  
  



  

    

Parses the given Ruby program read from src. src must be a String or an IO or a object with a #gets method.


  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 18



def Ripper.parse(src, filename = '(ripper)', lineno = 1)
  new(src, filename, lineno).parse
end


  








  

    .sexp(src, filename = '-', lineno = 1)  
  



  

    
EXPERIMENTAL



Parses src and create S-exp tree. Returns more readable tree rather than .sexp_raw. This method is mainly for developer use.



require 'ripper'
require 'pp'

pp Ripper.sexp("def m(a) nil end")
  #=> [:program,
       [[:def,
        [:@ident, "m", [1, 4]],
        [:paren, [:params, [[:@ident, "a", [1, 6]]], nil, nil, nil, nil]],
        [:bodystmt, [[:var_ref, [:@kw, "nil", [1, 9]]]], nil, nil, nil]]]]




  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/sexp.rb', line 31



def Ripper.sexp(src, filename = '-', lineno = 1)
  builder = SexpBuilderPP.new(src, filename, lineno)
  sexp = builder.parse
  sexp unless builder.error?
end


  








  

    .sexp_raw(src, filename = '-', lineno = 1)  
  



  

    
EXPERIMENTAL



Parses src and create S-exp tree. This method is mainly for developer use.



require 'ripper'
require 'pp'

pp Ripper.sexp_raw("def m(a) nil end")
  #=> [:program,
       [:stmts_add,
        [:stmts_new],
        [:def,
         [:@ident, "m", [1, 4]],
         [:paren, [:params, [[:@ident, "a", [1, 6]]], nil, nil, nil]],
         [:bodystmt,
          [:stmts_add, [:stmts_new], [:var_ref, [:@kw, "nil", [1, 9]]]],
          nil,
          nil,
          nil]]]]




  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/sexp.rb', line 57



def Ripper.sexp_raw(src, filename = '-', lineno = 1)
  builder = SexpBuilder.new(src, filename, lineno)
  sexp = builder.parse
  sexp unless builder.error?
end


  








  

    .slice(src, pattern, n = 0)  
  



  

    
EXPERIMENTAL



Parses src and return a string which was matched to pattern. pattern should be described as Regexp.



require 'ripper'

p Ripper.slice('def m(a) nil end', 'ident')                   #=> "m"
p Ripper.slice('def m(a) nil end', '[ident lparen rparen]+')  #=> "m(a)"
p Ripper.slice("<<EOS\nstring\nEOS",
               'heredoc_beg nl $(tstring_content*) heredoc_end', 1)
    #=> "string\n"




  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/lexer.rb', line 149



def Ripper.slice(src, pattern, n = 0)
  if m = token_match(src, pattern)
  then m.string(n)
  else nil
  end
end


  








  

    .token_match(src, pattern)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/lexer.rb', line 156



def Ripper.token_match(src, pattern)   #:nodoc:
  TokenPattern.compile(pattern).match(src)
end


  








  

    .tokenize(src, filename = '-', lineno = 1)  
  



  

    

Tokenizes the Ruby program and returns an array of strings.



p Ripper.tokenize("def m(a) nil end")
   # => ["def", " ", "m", "(", "a", ")", " ", "nil", " ", "end"]


  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/lexer.rb', line 21



def Ripper.tokenize(src, filename = '-', lineno = 1)
  Lexer.new(src, filename, lineno).tokenize
end


  







Instance Attribute Details



  

    #end_seen?  ⇒ Boolean  (readonly)  



  

    

Return true if parsed source ended by _END_.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11005



VALUE
rb_parser_end_seen_p(VALUE vparser)
{
    struct parser_params *p;

    TypedData_Get_Struct(vparser, struct parser_params, &parser_data_type, p);
    return p->ruby__end__seen ? Qtrue : Qfalse;
}


  








  

    #error?  ⇒ Boolean  (readonly)  



  

    

Return true if parsed source has errors.


  



  [ GitHub ]


  

  


# File 'parse.y', line 10989



static VALUE
ripper_error_p(VALUE vparser)
{
    struct parser_params *p;

    TypedData_Get_Struct(vparser, struct parser_params, &parser_data_type, p);
    return p->error_p ? Qtrue : Qfalse;
}


  








  

    #yydebug  ⇒ Boolean  (rw)  



  

    

Get yydebug.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11035



VALUE
rb_parser_get_yydebug(VALUE self)
{
    struct parser_params *p;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    return p->debug ? Qtrue : Qfalse;
}


  








  

    #yydebug=(flag)   (rw)  



  

    

Set yydebug.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11050



VALUE
rb_parser_set_yydebug(VALUE self, VALUE flag)
{
    struct parser_params *p;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    p->debug = RTEST(flag);
    return flag;
}


  







Instance Method Details



  

    #_dispatch_0   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 33



def _dispatch_0() nil end


  








  

    #_dispatch_1(a)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 34



def _dispatch_1(a) a end


  








  

    #_dispatch_2(a, b)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 35



def _dispatch_2(a, b) a end


  








  

    #_dispatch_3(a, b, c)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 36



def _dispatch_3(a, b, c) a end


  








  

    #_dispatch_4(a, b, c, d)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 37



def _dispatch_4(a, b, c, d) a end


  








  

    #_dispatch_5(a, b, c, d, e)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 38



def _dispatch_5(a, b, c, d, e) a end


  








  

    #_dispatch_6(a, b, c, d, e, f)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 39



def _dispatch_6(a, b, c, d, e, f) a end


  








  

    #_dispatch_7(a, b, c, d, e, f, g)   (private)
  

  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 40



def _dispatch_7(a, b, c, d, e, f, g) a end


  








  

    #column  ⇒ Integer   



  

    

Return column number of current parsing line. This number starts from 0.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11440



static VALUE
ripper_column(VALUE self)
{
    struct parser_params *p;
    long col;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    if (!ripper_initialized_p(p)) {
        rb_raise(rb_eArgError, "method called for uninitialized object");
    }
    if (NIL_P(p->parsing_thread)) return Qnil;
    col = p->lex.ptok - p->lex.pbeg;
    return LONG2NUM(col);
}


  








  

    #compile_error(msg)   (private)
  



  

    

This method is called when the parser found syntax error.


  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 61



def compile_error(msg)
end


  








  

    

      #dedent_string(input, width)  ⇒ Integer  (private)
      #dedent_string(input, width)  ⇒ Integer 
    

  



  

    

Alias for .dedent_string.


  





  








  

    #encoding  ⇒ Encoding   



  

    

Return encoding of the source.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11020



VALUE
rb_parser_encoding(VALUE vparser)
{
    struct parser_params *p;

    TypedData_Get_Struct(vparser, struct parser_params, &parser_data_type, p);
    return rb_enc_from_encoding(p->enc);
}


  








  

    #filename  ⇒ String   



  

    

Return current parsing filename.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11461



static VALUE
ripper_filename(VALUE self)
{
    struct parser_params *p;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    if (!ripper_initialized_p(p)) {
        rb_raise(rb_eArgError, "method called for uninitialized object");
    }
    return p->ruby_sourcefile_string;
}


  








  

    #lineno  ⇒ Integer   



  

    

Return line number of current parsing line. This number starts from 1.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11480



static VALUE
ripper_lineno(VALUE self)
{
    struct parser_params *p;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    if (!ripper_initialized_p(p)) {
        rb_raise(rb_eArgError, "method called for uninitialized object");
    }
    if (NIL_P(p->parsing_thread)) return Qnil;
    return INT2NUM(p->ruby_sourceline);
}


  








  

    #parse    



  

    

Start parsing and returns the value of the root action.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11412



static VALUE
ripper_parse(VALUE self)
{
    struct parser_params *p;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    if (!ripper_initialized_p(p)) {
        rb_raise(rb_eArgError, "method called for uninitialized object");
    }
    if (!NIL_P(p->parsing_thread)) {
        if (p->parsing_thread == rb_thread_current())
            rb_raise(rb_eArgError, "Ripper#parse is not reentrant");
        else
            rb_raise(rb_eArgError, "Ripper#parse is not multithread-safe");
    }
    p->parsing_thread = rb_thread_current();
    rb_ensure(ripper_parse0, self, ripper_ensure, self);

    return p->result;
}


  








  

    #state  ⇒ Integer   



  

    

Return scanner state of current token.


  



  [ GitHub ]


  

  


# File 'parse.y', line 11499



static VALUE
ripper_state(VALUE self)
{
    struct parser_params *p;

    TypedData_Get_Struct(self, struct parser_params, &parser_data_type, p);
    if (!ripper_initialized_p(p)) {
	rb_raise(rb_eArgError, "method called for uninitialized object");
    }
    if (NIL_P(p->parsing_thread)) return Qnil;
    return INT2NUM(p->lex.state);
}


  








  

    #warn(fmt, *args)   (private)
  



  

    

This method is called when weak warning is produced by the parser. fmt and args is printf style.


  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 52



def warn(fmt, *args)
end


  








  

    #warning(fmt, *args)   (private)
  



  

    

This method is called when strong warning is produced by the parser. fmt and args is printf style.


  



  [ GitHub ]


  

  


# File 'ext/ripper/lib/ripper/core.rb', line 57



def warning(fmt, *args)
end