Class: Rewrite::ByExample::EntityMatcher

Inherits:
Object
  • Object
show all
Defined in:
lib/rewrite/by_example/entity_matcher.rb

Overview

Matches a single something against a sexp such as an array or a literal symbol

Direct Known Subclasses

AnyEntity, Bind, NilEntity, SexpEntity, SymbolEntity

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#predicate ⇒ Object

Returns the value of attribute predicate.



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# File 'lib/rewrite/by_example/entity_matcher.rb', line 11

def predicate
  @predicate
end

Instance Method Details

#after_unfold ⇒ Object

advice for unfold



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# File 'lib/rewrite/by_example/entity_matcher.rb', line 40

def after_unfold
  
end

#fold(enum_of_bindings) ⇒ Object

takes an enumeration of bindings and returns nil or a sexp.

Note the identity: if x.unfold(sexp) is not nil, then sexp == x.fold(x.unfold(sexp))



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# File 'lib/rewrite/by_example/entity_matcher.rb', line 34

def fold(enum_of_bindings)
  raise 'implemented by includer'
end

#such_that!(&predicate_clause) ⇒ Object 



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# File 'lib/rewrite/by_example/entity_matcher.rb', line 13

def such_that!(&predicate_clause)
  self.predicate = predicate_clause
  self
end

#unfold(sexp) ⇒ Object

takes a sexp and returns nil or an enumeration of bindings, typically as a hash. Note that the empty hash is truthy, and this is what we want: it means a match that doesn’t perform any bindings

Note the identity: if x.fold(enum_of_bindings) is not nil, then enum_of_bindings == x.unfold(x.fold(enum_of_bindings))



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# File 'lib/rewrite/by_example/entity_matcher.rb', line 25

def unfold(sexp)
  raise 'implemented by includer'
end