Module: Sparkql::ParserTools

Included in:
Parser
Defined in:
lib/sparkql/parser_tools.rb

Overview

This is the guts of the parser internals and is mixed into the parser for organization.

Constant Summary collapse

DATE_TYPES =

Coercible types from highest precision to lowest

[:datetime, :date]
NUMBER_TYPES = 
[:decimal, :integer]
ARITHMETIC_TYPES = 
[:decimal, :integer, :field, :arithmetic]

Instance Method Summary collapse

Instance Method Details

#add_fold(n1, n2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 248

def add_fold(n1, n2)
  return if arithmetic_error?(n1) || arithmetic_error?(n2)

  { type: arithmetic_type(n1, n2), value: (escape_value(n1) + escape_value(n2)).to_s }
end

#arithmetic_error?(side) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sparkql/parser_tools.rb', line 238

def arithmetic_error?(side)
  side_type = side[:type] == :function ? side[:return_type] : side[:type]
  return false unless (!ARITHMETIC_TYPES.include?(side_type) || !ARITHMETIC_TYPES.include?(side_type))

  compile_error(:token => side[:value], :expression => side,
        :message => "Error attempting arithmetic with type: #{side_type}",
        :status => :fatal, :syntax => false, :constraint => true )
  true
end

#arithmetic_field(nested_representation) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 26

def arithmetic_field(nested_representation)
  lhs = nested_representation[:lhs]
  rhs = nested_representation[:rhs]

  if lhs[:type] == :field
    lhs[:value]
  elsif rhs[:type] == :field
    rhs[:value]
  elsif lhs.key?(:field)
    lhs[:field]
  elsif rhs.key?(:field)
    rhs[:field]
  elsif lhs[:type] == :arithmetic
    arithmetic_field(lhs)
  elsif rhs[:type] == :arithmetic
    arithmetic_field(rhs)
  else
    nil
  end
end

#arithmetic_type(num1, num2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 282

def arithmetic_type(num1, num2)
  if (num1[:type] == :decimal || num2[:type] == :decimal)
    :decimal
  else
    :integer
  end
end

#coercible_types(type1, type2) ⇒ Object

If both types support coercion with eachother, always selects the highest precision type to return as a reflection of the two. Any type that doesn’t support coercion with the other type returns nil



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# File 'lib/sparkql/parser_tools.rb', line 355

def coercible_types type1, type2
  if DATE_TYPES.include?(type1) && DATE_TYPES.include?(type2)
    DATE_TYPES.first
  elsif NUMBER_TYPES.include?(type1) && NUMBER_TYPES.include?(type2)
    NUMBER_TYPES.first
  else
    nil
  end
end

#div_fold(n1, n2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 266

def div_fold(n1, n2)
  return if arithmetic_error?(n1) ||
    arithmetic_error?(n2) ||
    zero_error?(n2)

  { type: arithmetic_type(n1, n2), value: (escape_value(n1) / escape_value(n2)).to_s }
end

#mod_fold(n1, n2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 274

def mod_fold(n1, n2)
  return if arithmetic_error?(n1) ||
    arithmetic_error?(n2) ||
    zero_error?(n2)

  { type: arithmetic_type(n1, n2), value: (escape_value(n1) % escape_value(n2)).to_s }
end

#mul_fold(n1, n2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 260

def mul_fold(n1, n2)
  return if arithmetic_error?(n1) || arithmetic_error?(n2)

  { type: arithmetic_type(n1, n2), value: (escape_value(n1) * escape_value(n2)).to_s }
end

#nested_function_depth(expression) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 365

def nested_function_depth(expression)
  return 0 unless expression && expression[:type] == :function

  height = 0
  queue = []
  queue.push(expression)

  while true
    count = queue.size
    return height if count == 0

    height += 1

    while count > 0
      node = queue.shift
      node[:args].each do |child|
        queue.push(child) if child[:type] == :function
      end
      count -= 1
    end
  end
end

#next_token ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 18

def next_token
  t = @lexer.shift
  while t[0] == :SPACE or t[0] == :NEWLINE
    t = @lexer.shift
  end
  t
end

#no_field_error(field, operator) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 47

def no_field_error(field, operator)
  tokenizer_error(:token => field,
                  :expression => {operator: operator, conjuction: 'And', conjunction_level: 0, level: @lexer.level},
                  :message => "Each expression must evaluate a field", :status => :fatal )
end

#on_error(error_token_id, error_value, value_stack) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 298

def on_error(error_token_id, error_value, value_stack)
  token_name = token_to_str(error_token_id)
  token_name.downcase!
  tokenizer_error(:token => @lexer.current_token_value, 
                  :message => "Error parsing token #{token_name}",
                  :status => :fatal, 
                  :syntax => true)    
end

#parse(str) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 9

def parse(str)
  @lexer = Sparkql::Lexer.new(str)
  @expression_count = 0
  results = do_parse
  return if results.nil?
  validate_expressions results
  results
end

#sub_fold(n1, n2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 254

def sub_fold(n1, n2)
  return if arithmetic_error?(n1) || arithmetic_error?(n2)

  { type: arithmetic_type(n1, n2), value: (escape_value(n1) - escape_value(n2)).to_s }
end

#tokenize_arithmetic(lhs, operator, rhs) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 224

def tokenize_arithmetic(lhs, operator, rhs)
  lhs = {type: :field, value: lhs} if lhs.is_a?(String)
  rhs = {type: :field, value: rhs} if rhs.is_a?(String)

  arithmetic_error?(lhs)
  arithmetic_error?(rhs)
  {
    type: :arithmetic,
    op: operator,
    lhs: lhs,
    rhs: rhs
  }
end

#tokenize_conjunction(exp1, conj, exp2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 103

def tokenize_conjunction(exp1, conj, exp2)
  exp2.first[:conjunction] = conj
  exp2.first[:conjunction_level] = @lexer.level
  exp1 + exp2
end

#tokenize_expression(field, op, val) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 53

def tokenize_expression(field, op, val)
  operator = get_operator(val,op) unless val.nil?

  field_manipulations = nil
  if field.is_a?(Hash) && field[:type] == :function
    function = Sparkql::FunctionResolver::SUPPORTED_FUNCTIONS[field[:function_name].to_sym]
    if function.nil?
      tokenizer_error(:token => field[:function_name],
        :message => "Unsupported function type", :status => :fatal )
    end
    field_manipulations = field
    field = field[:field]
  elsif field.is_a?(Hash) && field[:type] == :arithmetic
    field_manipulations = field
    field = arithmetic_field(field)
    no_field_error(field, operator) if field.nil?
  elsif field.is_a?(Hash)
    no_field_error(field, operator)
  end

  custom_field = !field.nil? && field.is_a?(String) && field.start_with?('"')

  block_group = (@lexer.level == 0) ? 0 : @lexer.block_group_identifier
  expression = {:field => field, :operator => operator, :conjunction => 'And',
    :conjunction_level => 0, :level => @lexer.level,
    :block_group => block_group, :custom_field => custom_field}

  if !field_manipulations.nil?
    # Keeping field_function and field_function_type for backward compatibility with datacon
    expression.merge!(field_manipulations: field_manipulations)

    if field_manipulations[:type] == :function
      expression.merge!(field_function: field_manipulations[:function_name],
                        field_function_type: field_manipulations[:return_type],
                        args: field_manipulations[:function_parameters])
    end
  end

  expression = val.merge(expression) unless val.nil?
  expression[:condition] ||= expression[:value]
  validate_level_depth expression
  validate_field_function_depth(expression[:field_manipulations])
  if operator.nil?
    tokenizer_error(:token => op, :expression => expression,
      :message => "Operator not supported for this type and value string", :status => :fatal )
  end
  @expression_count += 1
  [expression]
end

#tokenize_field_arg(field) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 187

def tokenize_field_arg(field)
  if field.is_a?(String)
    {
      :type => :field,
      :value => field,
    }
  else
    field
  end
end

#tokenize_function(name, f_args) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 198

def tokenize_function(name, f_args)
  @lexer.leveldown
  @lexer.block_group_identifier -= 1

  args = f_args.instance_of?(Array) ? f_args : [f_args]
  validate_multiple_arguments args
  condition_list = []
  args.each do |arg|
    condition_list << arg[:value] # Needs to be pure string value
    arg[:value] = escape_value(arg)
  end
  resolver = Sparkql::FunctionResolver.new(name, args)
  
  resolver.validate
  if(resolver.errors?)
    tokenizer_error(:token => @lexer.last_field, 
                    :message => "Error parsing function #{resolver.errors.join(',')}",
                    :status => :fatal, 
                    :syntax => true)    
    return nil
  else
    result = resolver.call()
    result.nil? ? result : result.merge(:condition => "#{name}(#{condition_list.join(',')})")
  end
end

#tokenize_function_args(lit1, lit2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 181

def tokenize_function_args(lit1, lit2)
  array = lit1.kind_of?(Array) ? lit1 : [lit1]
  array << lit2
  array
end

#tokenize_group(expressions) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 127

def tokenize_group(expressions)
  @lexer.leveldown
  expressions
end

#tokenize_list(list) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 132

def tokenize_list(list)
  return if list.nil?
  validate_multiple_values list[:value]
  list[:condition] ||= list[:value]
  list
end

#tokenize_literal_negation(number_token) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 139

def tokenize_literal_negation(number_token)
  old_val = case number_token[:type]
  when :integer
    number_token[:value].to_i
  when :decimal
    number_token[:value].to_f
  else
    tokenizer_error(:token => @lexer.current_token_value,
                    :expression => number_token,
                    :message => "Negation is only allowed for integer and floats",
                    :status => :fatal,
                    :syntax => true)
    return number_token
  end
  number_token[:value] = (-1 * old_val).to_s

  number_token
end

#tokenize_multiple(lit1, lit2) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 158

def tokenize_multiple(lit1, lit2)
  final_type = lit1[:type]
  if lit1[:type] != lit2[:type]
    final_type = coercible_types(lit1[:type],lit2[:type])
    if final_type.nil?
      final_type = lit1[:type]
      tokenizer_error(:token => @lexer.last_field, 
                      :message => "Type mismatch in field list.",
                      :status => :fatal, 
                      :syntax => true)
    end
  end
  array = Array(lit1[:value])
  condition = lit1[:condition] || lit1[:value] 
  array << lit2[:value]
  {
    :type => final_type ,
    :value => array,
    :multiple => "true",
    :condition => condition + "," + (lit2[:condition] || lit2[:value])
  }
end

#tokenize_unary_conjunction(conj, exp) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 109

def tokenize_unary_conjunction(conj, exp)
  # Handles the case when a SparkQL filter string
  # begins with a unary operator, and is nested, such as:
  #   Not (Not Field Eq 1)
  # In this instance we treat the outer unary as a conjunction. With any other
  # expression this would be the case, so that should make processing 
  # consistent.
  if exp.first[:unary] && @lexer.level == 0
    exp.first[:conjunction] =  conj
    exp.first[:conjunction_level] = @lexer.level
  else
    exp.first[:unary] = conj
    exp.first[:unary_level] = @lexer.level
  end

  exp
end

#validate_expressions(results) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 323

def validate_expressions results
  if results.size > max_expressions 
    compile_error(:token => results[max_expressions][:field], :expression => results[max_expressions],
          :message => "You have exceeded the maximum expression count.  Please limit to no more than #{max_expressions} expressions in a filter.",
          :status => :fatal, :syntax => false, :constraint => true )
    results.slice!(max_expressions..-1)
  end
end

#validate_field_function_depth(expression) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 315

def validate_field_function_depth(expression)
  if nested_function_depth(expression) > max_function_depth
    compile_error(:token => "(", :expression => expression,
          :message => "You have exceeded the maximum function nesting level.  Please nest no more than #{max_function_depth} levels deep.",
          :status => :fatal, :syntax => false, :constraint => true )
  end
end

#validate_level_depth(expression) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 307

def validate_level_depth expression
  if @lexer.level > max_level_depth
    compile_error(:token => "(", :expression => expression,
          :message => "You have exceeded the maximum nesting level.  Please nest no more than #{max_level_depth} levels deep.",
          :status => :fatal, :syntax => false, :constraint => true )
  end
end

#validate_multiple_arguments(args) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 342

def validate_multiple_arguments args
  args = Array(args)
  if args.size > max_values 
    compile_error(:token => args[max_values],
          :message => "You have exceeded the maximum parameter count.  Please limit to #{max_values} parameters to a single function.",
          :status => :fatal, :syntax => false, :constraint => true )
    args.slice!(max_values..-1)
  end
end

#validate_multiple_values(values) ⇒ Object 



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# File 'lib/sparkql/parser_tools.rb', line 332

def validate_multiple_values values
  values = Array(values)
  if values.size > max_values 
    compile_error(:token => values[max_values],
          :message => "You have exceeded the maximum value count.  Please limit to #{max_values} values in a single expression.",
          :status => :fatal, :syntax => false, :constraint => true )
    values.slice!(max_values..-1)
  end
end

#zero_error?(number) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sparkql/parser_tools.rb', line 290

def zero_error?(number)
  return unless escape_value(number) == 0

  compile_error(:token => "#{number[:value]}", :expression => number,
        :message => "Error attempting to divide by zero",
        :status => :fatal, :syntax => false, :constraint => true )
end