Class: Parser::Builders::Default

Inherits:
Object
  • Object
show all
Defined in:
lib/parser/builders/default.rb

Overview

Default AST builder. Uses AST::Nodes.

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Default

Initializes attributes:

* `emit_file_line_as_literals`: `true`


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# File 'lib/parser/builders/default.rb', line 243

def initialize
  @emit_file_line_as_literals = true
end

Class Attribute Details

.emit_arg_inside_procarg0 ⇒ Boolean

AST compatibility attribute; causes a single non-mlhs block argument to be wrapped in s(:procarg0).

If set to false (the default), block arguments |a| are emitted as s(:args, s(:procarg0, :a))

If set to true, block arguments |a| are emitted as s(:args, s(:procarg0, s(:arg, :a))

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 97

def emit_arg_inside_procarg0
  @emit_arg_inside_procarg0
end

.emit_encoding ⇒ Boolean

AST compatibility attribute; locations of __ENCODING__ are not the same as locations of Encoding::UTF_8 causing problems during rewriting, all new code should set this attribute to true.

If set to false (the default), __ENCODING__ is emitted as s(:const, s(:const, nil, :Encoding), :UTF_8).

If set to true, __ENCODING__ is emitted as s(:__ENCODING__).

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 58

def emit_encoding
  @emit_encoding
end

.emit_forward_arg ⇒ Boolean

AST compatibility attribute; arguments forwarding initially didn't have support for leading arguments (i.e. def m(a, ...); end was a syntax error). However, Ruby 3.0 added support for any number of arguments in front of the ....

If set to false (the default):

1. `def m(...) end` is emitted as
 s(:def, :m, s(:forward_args), nil)
2. `def m(a, b, ...) end` is emitted as
 s(:def, :m,
   s(:args, s(:arg, :a), s(:arg, :b), s(:forward_arg)))

If set to true it uses a single format:

1. `def m(...) end` is emitted as
 s(:def, :m, s(:args, s(:forward_arg)))
2. `def m(a, b, ...) end` is emitted as
 s(:def, :m, s(:args, s(:arg, :a), s(:arg, :b), s(:forward_arg)))

It does't matter that much on 2.7 (because there can't be any leading arguments), but on 3.0 it should be better enabled to use a single AST format.

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 126

def emit_forward_arg
  @emit_forward_arg
end

.emit_index ⇒ Boolean

AST compatibility attribute; indexed assignment, x[] = 1, is not semantically equivalent to calling the method directly, x.[]=(1). Specifically, in the former case, the expression's value is always 1, and in the latter case, the expression's value is the return value of the []= method.

If set to false (the default), self[1] is emitted as s(:send, s(:self), :[], s(:int, 1)), and self[1] = 2 is emitted as s(:send, s(:self), :[]=, s(:int, 1), s(:int, 2)).

If set to true, self[1] is emitted as s(:index, s(:self), s(:int, 1)), and self[1] = 2 is emitted as s(:indexasgn, s(:self), s(:int, 1), s(:int, 2)).

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 80

def emit_index
  @emit_index
end

.emit_kwargs ⇒ Object

AST compatibility attribute; Starting from Ruby 2.7 keyword arguments of method calls that are passed explicitly as a hash (i.e. with curly braces) are treated as positional arguments and Ruby 2.7 emits a warning on such method call. Ruby 3.0 given an ArgumentError.

If set to false (the default) the last hash argument is emitted as hash:

(send nil :foo
  (hash
    (pair
      (sym :bar)
      (int 42))))

If set to true it is emitted as kwargs:

(send nil :foo
  (kwargs
    (pair
      (sym :bar)
      (int 42))))

Note that kwargs node is just a replacement for hash argument, so if there's are multiple arguments (or a kwsplat) all of them are wrapped into kwargs instead of hash:

(send nil :foo
  (kwargs
    (pair
      (sym :a)
      (int 42))
    (kwsplat
      (send nil :b))
    (pair
      (sym :c)
      (int 10))))



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# File 'lib/parser/builders/default.rb', line 174

def emit_kwargs
  @emit_kwargs
end

.emit_lambda ⇒ Boolean

AST compatibility attribute; since -> {} is not semantically equivalent to lambda {}, all new code should set this attribute to true.

If set to false (the default), -> {} is emitted as s(:block, s(:send, nil, :lambda), s(:args), nil).

If set to true, -> {} is emitted as s(:block, s(:lambda), s(:args), nil).

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 22

def emit_lambda
  @emit_lambda
end

.emit_match_pattern ⇒ Object

AST compatibility attribute; Starting from 3.0 Ruby returns true/false from single-line pattern matching with in keyword.

Before 3.0 there was an exception if given value doesn't match pattern.

NOTE: This attribute affects only Ruby 2.7 grammar. 3.0 grammar always emits match_pattern/match_pattern_p

If compatibility attribute set to false foo in bar is emitted as in_match:

(in-match
  (send nil :foo)
  (match-var :bar))

If set to true it's emitted as match_pattern_p:

(match-pattern-p
  (send nil :foo)
  (match-var :bar))



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# File 'lib/parser/builders/default.rb', line 203

def emit_match_pattern
  @emit_match_pattern
end

.emit_procarg0 ⇒ Boolean

AST compatibility attribute; block arguments of m { |a| } are not semantically equivalent to block arguments of m { |a,| } or m { |a, b| }, all new code should set this attribute to true.

If set to false (the default), arguments of m { |a| } are emitted as s(:args, s(:arg, :a)).

If set to true, arguments of m { |a| } are emitted as `s(:args, s(:procarg0, :a)).

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 40

def emit_procarg0
  @emit_procarg0
end

Instance Attribute Details

#emit_file_line_as_literals ⇒ Boolean

If set to true (the default), __FILE__ and __LINE__ are transformed to literal nodes. For example, s(:str, "lib/foo.rb") and s(:int, 10).

If set to false, __FILE__ and __LINE__ are emitted as-is, i.e. as s(:__FILE__) and s(:__LINE__) nodes.

Source maps are identical in both cases.

Returns:

  • (Boolean) 


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# File 'lib/parser/builders/default.rb', line 237

def emit_file_line_as_literals
  @emit_file_line_as_literals
end

#parser ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/parser/builders/default.rb', line 225

def parser
  @parser
end

Class Method Details

.modernize ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/parser/builders/default.rb', line 211

def modernize
  @emit_lambda = true
  @emit_procarg0 = true
  @emit_encoding = true
  @emit_index = true
  @emit_arg_inside_procarg0 = true
  @emit_forward_arg = true
  @emit_kwargs = true
  @emit_match_pattern = true
end