Class: JSE::Ast::ExpressionNode

Inherits:
AstNode
  • Object
show all
Defined in:
lib/jse/ast/nodes.rb

Instance Attribute Summary collapse

Attributes inherited from AstNode

#env

Instance Method Summary collapse

Constructor Details

#initialize(operator, value, metadata, env) ⇒ ExpressionNode

Returns a new instance of ExpressionNode.



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# File 'lib/jse/ast/nodes.rb', line 98

def initialize(operator, value, metadata, env)
  super(env)
  @operator = operator
  @value = value
  @metadata = metadata
end

Instance Attribute Details

#metadata ⇒ Object (readonly)

Returns the value of attribute metadata.



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# File 'lib/jse/ast/nodes.rb', line 105

def metadata
  @metadata
end

#operator ⇒ Object (readonly)

Returns the value of attribute operator.



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# File 'lib/jse/ast/nodes.rb', line 105

def operator
  @operator
end

#value ⇒ Object (readonly)

Returns the value of attribute value.



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# File 'lib/jse/ast/nodes.rb', line 105

def value
  @value
end

Instance Method Details

#apply(call_env) ⇒ Object

Raises:

  • (NameError) 


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# File 'lib/jse/ast/nodes.rb', line 107

def apply(call_env)
  functor = call_env.resolve(@operator)
  raise NameError, "Unknown operator: #{@operator}" if functor.nil?

  evaluated_meta = @metadata.transform_values { |v| deep_eval(call_env, v) }
  call_env.set_meta(evaluated_meta)
  begin
    args = case @operator
    when "$quote"
      [@value]
    when "$expr"
      [call_env.eval(@value)]
    when "$sql"
      # $sql receives raw JSON stored in LiteralNode by parser
      if @value.is_a?(LiteralNode)
        [@value.value]
      else
        [@value]
      end
    else
      if @value.is_a?(ArrayNode)
        @value.elements.map { |e| deep_eval(call_env, e) }
      else
        [call_env.eval(@value)]
      end
    end

    functor.call(call_env, *args)
  ensure
    call_env.clear_meta
  end
end

#to_json ⇒ Object 



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# File 'lib/jse/ast/nodes.rb', line 140

def to_json
  result = { @operator => @value.to_json }
  @metadata.each { |k, v| result[k] = v }
  result
end