/
function.rb
652 lines (574 loc) · 19 KB
/
function.rb
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module JMESPath
# @api private
module Nodes
class Function < Node
FUNCTIONS = {}
def initialize(children, options = {})
@children = children
@options = options
@disable_visit_errors = @options[:disable_visit_errors]
end
def self.create(name, children, options = {})
if (type = FUNCTIONS[name])
type.new(children, options)
else
raise Errors::UnknownFunctionError, "unknown function #{name}()"
end
end
def visit(value)
call(@children.map { |child| child.visit(value) })
end
def optimize
self.class.new(@children.map(&:optimize), @options)
end
class FunctionName
attr_reader :name
def initialize(name)
@name = name
end
end
private
def maybe_raise(error_type, message)
unless @disable_visit_errors
raise error_type, message
end
end
def call(args)
nil
end
end
module TypeChecker
def get_type(value)
if value.respond_to?(:to_str)
STRING_TYPE
elsif value == true || value == false
BOOLEAN_TYPE
elsif value == nil
NULL_TYPE
elsif value.is_a?(Numeric)
NUMBER_TYPE
elsif value.respond_to?(:to_hash) || value.is_a?(Struct)
OBJECT_TYPE
elsif value.respond_to?(:to_ary)
ARRAY_TYPE
elsif value.is_a?(Expression)
EXPRESSION_TYPE
end
end
ARRAY_TYPE = 0
BOOLEAN_TYPE = 1
EXPRESSION_TYPE = 2
NULL_TYPE = 3
NUMBER_TYPE = 4
OBJECT_TYPE = 5
STRING_TYPE = 6
TYPE_NAMES = {
ARRAY_TYPE => 'array',
BOOLEAN_TYPE => 'boolean',
EXPRESSION_TYPE => 'expression',
NULL_TYPE => 'null',
NUMBER_TYPE => 'number',
OBJECT_TYPE => 'object',
STRING_TYPE => 'string',
}.freeze
end
class AbsFunction < Function
FUNCTIONS['abs'] = self
def call(args)
if args.count == 1
value = args.first
else
return maybe_raise Errors::InvalidArityError, "function abs() expects one argument"
end
if Numeric === value
value.abs
else
return maybe_raise Errors::InvalidTypeError, "function abs() expects a number"
end
end
end
class AvgFunction < Function
FUNCTIONS['avg'] = self
def call(args)
if args.count == 1
values = args.first
else
return maybe_raise Errors::InvalidArityError, "function avg() expects one argument"
end
if values.respond_to?(:to_ary)
values = values.to_ary
return nil if values.empty?
values.inject(0) do |total,n|
if Numeric === n
total + n
else
return maybe_raise Errors::InvalidTypeError, "function avg() expects numeric values"
end
end / values.size.to_f
else
return maybe_raise Errors::InvalidTypeError, "function avg() expects a number"
end
end
end
class CeilFunction < Function
FUNCTIONS['ceil'] = self
def call(args)
if args.count == 1
value = args.first
else
return maybe_raise Errors::InvalidArityError, "function ceil() expects one argument"
end
if Numeric === value
value.ceil
else
return maybe_raise Errors::InvalidTypeError, "function ceil() expects a numeric value"
end
end
end
class ContainsFunction < Function
FUNCTIONS['contains'] = self
def call(args)
if args.count == 2
haystack = args[0]
needle = args[1]
if haystack.respond_to?(:to_str)
haystack.to_str.include?(needle)
elsif haystack.respond_to?(:to_ary)
haystack.to_ary.include?(needle)
else
return maybe_raise Errors::InvalidTypeError, "contains expects 2nd arg to be a list"
end
else
return maybe_raise Errors::InvalidArityError, "function contains() expects 2 arguments"
end
end
end
class FloorFunction < Function
FUNCTIONS['floor'] = self
def call(args)
if args.count == 1
value = args.first
else
return maybe_raise Errors::InvalidArityError, "function floor() expects one argument"
end
if Numeric === value
value.floor
else
return maybe_raise Errors::InvalidTypeError, "function floor() expects a numeric value"
end
end
end
class LengthFunction < Function
FUNCTIONS['length'] = self
def call(args)
if args.count == 1
value = args.first
else
return maybe_raise Errors::InvalidArityError, "function length() expects one argument"
end
if value.respond_to?(:to_hash) || value.respond_to?(:to_ary) || value.respond_to?(:to_str)
value.size
else
return maybe_raise Errors::InvalidTypeError, "function length() expects string, array or object"
end
end
end
class Map < Function
FUNCTIONS['map'] = self
def call(args)
if args.count != 2
return maybe_raise Errors::InvalidArityError, "function map() expects two arguments"
end
if Nodes::Expression === args[0]
expr = args[0]
else
return maybe_raise Errors::InvalidTypeError, "function map() expects the first argument to be an expression"
end
if args[1].respond_to?(:to_ary)
list = args[1].to_ary
else
return maybe_raise Errors::InvalidTypeError, "function map() expects the second argument to be an list"
end
list.map { |value| expr.eval(value) }
end
end
class MaxFunction < Function
include TypeChecker
FUNCTIONS['max'] = self
def call(args)
if args.count == 1
values = args.first
else
return maybe_raise Errors::InvalidArityError, "function max() expects one argument"
end
if values.respond_to?(:to_ary)
values = values.to_ary
return nil if values.empty?
first = values.first
first_type = get_type(first)
unless first_type == NUMBER_TYPE || first_type == STRING_TYPE
msg = "function max() expects numeric or string values"
return maybe_raise Errors::InvalidTypeError, msg
end
values.inject([first, first_type]) do |(max, max_type), v|
v_type = get_type(v)
if max_type == v_type
v > max ? [v, v_type] : [max, max_type]
else
msg = "function max() encountered a type mismatch in sequence: "
msg << "#{max_type}, #{v_type}"
return maybe_raise Errors::InvalidTypeError, msg
end
end.first
else
return maybe_raise Errors::InvalidTypeError, "function max() expects an array"
end
end
end
class MinFunction < Function
include TypeChecker
FUNCTIONS['min'] = self
def call(args)
if args.count == 1
values = args.first
else
return maybe_raise Errors::InvalidArityError, "function min() expects one argument"
end
if values.respond_to?(:to_ary)
values = values.to_ary
return nil if values.empty?
first = values.first
first_type = get_type(first)
unless first_type == NUMBER_TYPE || first_type == STRING_TYPE
msg = "function min() expects numeric or string values"
return maybe_raise Errors::InvalidTypeError, msg
end
values.inject([first, first_type]) do |(min, min_type), v|
v_type = get_type(v)
if min_type == v_type
v < min ? [v, v_type] : [min, min_type]
else
msg = "function min() encountered a type mismatch in sequence: "
msg << "#{min_type}, #{v_type}"
return maybe_raise Errors::InvalidTypeError, msg
end
end.first
else
return maybe_raise Errors::InvalidTypeError, "function min() expects an array"
end
end
end
class TypeFunction < Function
include TypeChecker
FUNCTIONS['type'] = self
def call(args)
if args.count == 1
TYPE_NAMES[get_type(args.first)]
else
return maybe_raise Errors::InvalidArityError, "function type() expects one argument"
end
end
end
class KeysFunction < Function
FUNCTIONS['keys'] = self
def call(args)
if args.count == 1
value = args.first
if value.respond_to?(:to_hash)
value.to_hash.keys.map(&:to_s)
elsif value.is_a?(Struct)
value.members.map(&:to_s)
else
return maybe_raise Errors::InvalidTypeError, "function keys() expects a hash"
end
else
return maybe_raise Errors::InvalidArityError, "function keys() expects one argument"
end
end
end
class ValuesFunction < Function
FUNCTIONS['values'] = self
def call(args)
if args.count == 1
value = args.first
if value.respond_to?(:to_hash)
value.to_hash.values
elsif value.is_a?(Struct)
value.to_h.values
elsif value.respond_to?(:to_ary)
value.to_ary
else
return maybe_raise Errors::InvalidTypeError, "function values() expects an array or a hash"
end
else
return maybe_raise Errors::InvalidArityError, "function values() expects one argument"
end
end
end
class JoinFunction < Function
FUNCTIONS['join'] = self
def call(args)
if args.count == 2
glue = args[0]
values = args[1]
if !(String === glue)
return maybe_raise Errors::InvalidTypeError, "function join() expects the first argument to be a string"
elsif values.respond_to?(:to_ary) && values.to_ary.all? { |v| String === v }
values.to_ary.join(glue)
else
return maybe_raise Errors::InvalidTypeError, "function join() expects values to be an array of strings"
end
else
return maybe_raise Errors::InvalidArityError, "function join() expects an array of strings"
end
end
end
class ToStringFunction < Function
FUNCTIONS['to_string'] = self
def call(args)
if args.count == 1
value = args.first
String === value ? value : value.to_json
else
return maybe_raise Errors::InvalidArityError, "function to_string() expects one argument"
end
end
end
class ToNumberFunction < Function
FUNCTIONS['to_number'] = self
def call(args)
if args.count == 1
begin
value = Float(args.first)
Integer(value) === value ? value.to_i : value
rescue
nil
end
else
return maybe_raise Errors::InvalidArityError, "function to_number() expects one argument"
end
end
end
class SumFunction < Function
FUNCTIONS['sum'] = self
def call(args)
if args.count == 1 && args.first.respond_to?(:to_ary)
args.first.to_ary.inject(0) do |sum,n|
if Numeric === n
sum + n
else
return maybe_raise Errors::InvalidTypeError, "function sum() expects values to be numeric"
end
end
else
return maybe_raise Errors::InvalidArityError, "function sum() expects one argument"
end
end
end
class NotNullFunction < Function
FUNCTIONS['not_null'] = self
def call(args)
if args.count > 0
args.find { |value| !value.nil? }
else
return maybe_raise Errors::InvalidArityError, "function not_null() expects one or more arguments"
end
end
end
class SortFunction < Function
include TypeChecker
FUNCTIONS['sort'] = self
def call(args)
if args.count == 1
value = args.first
if value.respond_to?(:to_ary)
value = value.to_ary
# every element in the list must be of the same type
array_type = get_type(value[0])
if array_type == STRING_TYPE || array_type == NUMBER_TYPE || value.size == 0
# stable sort
n = 0
value.sort_by do |v|
value_type = get_type(v)
if value_type != array_type
msg = "function sort() expects values to be an array of only numbers, or only integers"
return maybe_raise Errors::InvalidTypeError, msg
end
n += 1
[v, n]
end
else
return maybe_raise Errors::InvalidTypeError, "function sort() expects values to be an array of numbers or integers"
end
else
return maybe_raise Errors::InvalidTypeError, "function sort() expects values to be an array of numbers or integers"
end
else
return maybe_raise Errors::InvalidArityError, "function sort() expects one argument"
end
end
end
class SortByFunction < Function
include TypeChecker
FUNCTIONS['sort_by'] = self
def call(args)
if args.count == 2
if get_type(args[0]) == ARRAY_TYPE && get_type(args[1]) == EXPRESSION_TYPE
values = args[0]
expression = args[1]
array_type = get_type(expression.eval(values[0]))
if array_type == STRING_TYPE || array_type == NUMBER_TYPE || values.size == 0
# stable sort the list
n = 0
values.sort_by do |value|
value = expression.eval(value)
value_type = get_type(value)
if value_type != array_type
msg = "function sort() expects values to be an array of only numbers, or only integers"
return maybe_raise Errors::InvalidTypeError, msg
end
n += 1
[value, n]
end
else
return maybe_raise Errors::InvalidTypeError, "function sort() expects values to be an array of numbers or integers"
end
else
return maybe_raise Errors::InvalidTypeError, "function sort_by() expects an array and an expression"
end
else
return maybe_raise Errors::InvalidArityError, "function sort_by() expects two arguments"
end
end
end
module CompareBy
include TypeChecker
def compare_by(mode, *args)
if args.count == 2
values = args[0]
expression = args[1]
if get_type(values) == ARRAY_TYPE && get_type(expression) == EXPRESSION_TYPE
type = get_type(expression.eval(values.first))
if type != NUMBER_TYPE && type != STRING_TYPE
msg = "function #{mode}() expects values to be strings or numbers"
return maybe_raise Errors::InvalidTypeError, msg
end
values.send(mode) do |entry|
value = expression.eval(entry)
value_type = get_type(value)
if value_type != type
msg = "function #{mode}() encountered a type mismatch in "
msg << "sequence: #{type}, #{value_type}"
return maybe_raise Errors::InvalidTypeError, msg
end
value
end
else
msg = "function #{mode}() expects an array and an expression"
return maybe_raise Errors::InvalidTypeError, msg
end
else
msg = "function #{mode}() expects two arguments"
return maybe_raise Errors::InvalidArityError, msg
end
end
end
class MaxByFunction < Function
include CompareBy
FUNCTIONS['max_by'] = self
def call(args)
compare_by(:max_by, *args)
end
end
class MinByFunction < Function
include CompareBy
FUNCTIONS['min_by'] = self
def call(args)
compare_by(:min_by, *args)
end
end
class EndsWithFunction < Function
include TypeChecker
FUNCTIONS['ends_with'] = self
def call(args)
if args.count == 2
search, suffix = args
search_type = get_type(search)
suffix_type = get_type(suffix)
if search_type != STRING_TYPE
msg = "function ends_with() expects first argument to be a string"
return maybe_raise Errors::InvalidTypeError, msg
end
if suffix_type != STRING_TYPE
msg = "function ends_with() expects second argument to be a string"
return maybe_raise Errors::InvalidTypeError, msg
end
search.end_with?(suffix)
else
msg = "function ends_with() expects two arguments"
return maybe_raise Errors::InvalidArityError, msg
end
end
end
class StartsWithFunction < Function
include TypeChecker
FUNCTIONS['starts_with'] = self
def call(args)
if args.count == 2
search, prefix = args
search_type = get_type(search)
prefix_type = get_type(prefix)
if search_type != STRING_TYPE
msg = "function starts_with() expects first argument to be a string"
return maybe_raise Errors::InvalidTypeError, msg
end
if prefix_type != STRING_TYPE
msg = "function starts_with() expects second argument to be a string"
return maybe_raise Errors::InvalidTypeError, msg
end
search.start_with?(prefix)
else
msg = "function starts_with() expects two arguments"
return maybe_raise Errors::InvalidArityError, msg
end
end
end
class MergeFunction < Function
FUNCTIONS['merge'] = self
def call(args)
if args.count == 0
msg = "function merge() expects 1 or more arguments"
return maybe_raise Errors::InvalidArityError, msg
end
args.inject({}) do |h, v|
h.merge(v)
end
end
end
class ReverseFunction < Function
FUNCTIONS['reverse'] = self
def call(args)
if args.count == 0
msg = "function reverse() expects 1 or more arguments"
return maybe_raise Errors::InvalidArityError, msg
end
value = args.first
if value.respond_to?(:to_ary)
value.to_ary.reverse
elsif String === value
value.reverse
else
msg = "function reverse() expects an array or string"
return maybe_raise Errors::InvalidTypeError, msg
end
end
end
class ToArrayFunction < Function
FUNCTIONS['to_array'] = self
def call(args)
value = args.first
value.respond_to?(:to_ary) ? value.to_ary : [value]
end
end
end
end