Class: Neo4j::Core::Cypher::Expression

Inherits:
Object
  • Object
show all
Defined in:
lib/neo4j-core/cypher/cypher.rb

Direct Known Subclasses

ExprOp, Limit, Match, OrderBy, Predicate, Return, Skip, Start, Where

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(expressions, clause) ⇒ Expression

Returns a new instance of Expression.



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# File 'lib/neo4j-core/cypher/cypher.rb', line 238

def initialize(expressions, clause)
  @clause = clause
  @expressions = expressions
  insert_last(clause)
  @separator = ","
end

Instance Attribute Details

#clause ⇒ Object

Returns the value of attribute clause.



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# File 'lib/neo4j-core/cypher/cypher.rb', line 236

def clause
  @clause
end

#expressions ⇒ Object (readonly)

Returns the value of attribute expressions.



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# File 'lib/neo4j-core/cypher/cypher.rb', line 235

def expressions
  @expressions
end

#separator ⇒ Object

Returns the value of attribute separator.



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# File 'lib/neo4j-core/cypher/cypher.rb', line 236

def separator
  @separator
end

Instance Method Details

#insert_last(clause) ⇒ Object 



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# File 'lib/neo4j-core/cypher/cypher.rb', line 245

def insert_last(clause)
  curr_clause = clause
  while (i = @expressions.reverse.index { |e| e.clause == curr_clause }).nil? && curr_clause != :start
    curr_clause = prev_clause(curr_clause)
  end

  if i.nil?
    @expressions << self
  else
    pos = @expressions.size - i
    @expressions.insert(pos, self)
  end
end

#prefix ⇒ Object 



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# File 'lib/neo4j-core/cypher/cypher.rb', line 267

def prefix
  prefixes[clause]
end

#prefixes ⇒ Object 



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# File 'lib/neo4j-core/cypher/cypher.rb', line 263

def prefixes
  {:start => "START", :where => " WHERE", :match => " MATCH", :return => " RETURN", :order_by => " ORDER BY", :skip => " SKIP", :limit => " LIMIT"}
end

#prev_clause(clause) ⇒ Object 



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# File 'lib/neo4j-core/cypher/cypher.rb', line 259

def prev_clause(clause)
  {:limit => :skip, :skip => :order_by, :order_by => :return, :return => :where, :where => :match, :match => :start}[clause]
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/neo4j-core/cypher/cypher.rb', line 271

def valid?
  true
end