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]

Instance Method Summary collapse

Instance Method Details

#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



200
201
202
203
204
205
206
207
208
 
# File 'lib/sparkql/parser_tools.rb', line 200

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

#next_token ⇒ Object 



17
18
19
20
21
22
23
 
# File 'lib/sparkql/parser_tools.rb', line 17

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

#on_error(error_token_id, error_value, value_stack) ⇒ Object 



150
151
152
153
154
155
156
157
158
 
# File 'lib/sparkql/parser_tools.rb', line 150

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

#parse(str) ⇒ Object 



8
9
10
11
12
13
14
15
 
# File 'lib/sparkql/parser_tools.rb', line 8

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

#tokenize_conjunction(exp1, conj, exp2) ⇒ Object 



56
57
58
59
60
 
# File 'lib/sparkql/parser_tools.rb', line 56

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 



25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/sparkql/parser_tools.rb', line 25

def tokenize_expression(field, op, val)
  operator = get_operator(val,op) unless val.nil?
  field_args = {}
  # Function support for fields is stapled in here. The function information
  # is remapped to the expression
  if field.is_a?(Hash) && field[:type] == :function
    function = Sparkql::FunctionResolver::SUPPORTED_FUNCTIONS[field[:value].to_sym]
    if !function.nil?
      field_args[:field_function] = field[:value]
      field_args[:field_function_type] = function[:return_type]
    else
      tokenizer_error(:token => field[:value], 
        :message => "Unsupported function type", :status => :fatal )
    end
    field = field[:args].first
  end
  custom_field = field.start_with?('"')
  block_group = (@lexer.level == 0) ? 0 : @lexer.block_group_identifier
  expression = {:field => field, :operator => operator, :conjunction => 'And', 
    :level => @lexer.level, :block_group => block_group, :custom_field => custom_field}.merge!(field_args)
  expression = val.merge(expression) unless val.nil?
  expression[:condition] ||= expression[:value]
  validate_level_depth expression
  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 



117
118
119
120
121
122
 
# File 'lib/sparkql/parser_tools.rb', line 117

def tokenize_field_arg(field)
  {
    :type => :field,
    :value => field,
  }
end

#tokenize_function(name, f_args) ⇒ Object 



124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
 
# File 'lib/sparkql/parser_tools.rb', line 124

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()
    return result.nil? ? result : result.merge(:condition => "#{name}(#{condition_list.join(',')})")
  end
end

#tokenize_function_args(lit1, lit2) ⇒ Object 



111
112
113
114
115
 
# File 'lib/sparkql/parser_tools.rb', line 111

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

#tokenize_group(expressions) ⇒ Object 



77
78
79
80
 
# File 'lib/sparkql/parser_tools.rb', line 77

def tokenize_group(expressions)
  @lexer.leveldown
  expressions
end

#tokenize_list(list) ⇒ Object 



82
83
84
85
86
 
# File 'lib/sparkql/parser_tools.rb', line 82

def tokenize_list(list)
  validate_multiple_values list[:value]
  list[:condition] ||= list[:value]
  list
end

#tokenize_multiple(lit1, lit2) ⇒ Object 



88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
 
# File 'lib/sparkql/parser_tools.rb', line 88

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 



62
63
64
65
66
67
68
69
70
71
72
73
74
75
 
# File 'lib/sparkql/parser_tools.rb', line 62

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.
  if @expression_count == 1 && @lexer.level > 0
    exp.first[:conjunction] = conj
    exp.first[:conjunction_level] = @lexer.level - 1
  end
  exp.first[:unary] = conj
  exp.first[:unary_level] = @lexer.level

  exp
end

#validate_expressions(results) ⇒ Object 



168
169
170
171
172
173
174
175
 
# File 'lib/sparkql/parser_tools.rb', line 168

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_level_depth(expression) ⇒ Object 



160
161
162
163
164
165
166
 
# File 'lib/sparkql/parser_tools.rb', line 160

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 



187
188
189
190
191
192
193
194
195
 
# File 'lib/sparkql/parser_tools.rb', line 187

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 



177
178
179
180
181
182
183
184
185
 
# File 'lib/sparkql/parser_tools.rb', line 177

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