Module: RubyLisp::Util

Defined in:
lib/rubylisp/util.rb,
lib/rubylisp/types.rb

Class Method Summary collapse

Class Method Details

.assert_arg_type(sexp, arg_number, arg_type) ⇒ Object 



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# File 'lib/rubylisp/util.rb', line 25

def assert_arg_type sexp, arg_number, arg_type
  fn = sexp[0]
  fn_name = fn.value
  arg = if arg_number == 'last'
          sexp.last
        else
          sexp[arg_number]
        end

  arg_description = if arg_number == 'last'
                      'The last argument'
                    else
                      "Argument ##{arg_number}"
                    end

  arg_types = if arg_type.class == Array
                arg_type
              else
                [arg_type]
              end

  expected = case arg_types.count
             when 1
               arg_types.first
             when 2
               arg_types.join(' or ')
             else
               last_arg_type = arg_types.pop
               arg_types.join(', ') + " or #{last_arg_type}"
             end

  if arg_types.none? {|type| arg.is_a? type}
    raise RuntimeError,
          "#{arg_description} to `#{fn_name}` must be a " +
          "#{expected}; got a #{arg.class}."
  end
end

.assert_at_least_n_args(sexp, num_args) ⇒ Object 



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# File 'lib/rubylisp/util.rb', line 15

def assert_at_least_n_args sexp, num_args
  fn, *args = sexp
  fn_name = fn.value
  unless args.count >= num_args
    raise RuntimeError,
          "Wrong number of arguments passed to `#{fn_name}`; " +
          "got #{args.count}, expected at least #{num_args}."
  end
end

.assert_number_of_args(sexp, num_args) ⇒ Object 



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# File 'lib/rubylisp/util.rb', line 5

def assert_number_of_args sexp, num_args
  fn, *args = sexp
  fn_name = fn.value
  unless args.count == num_args
    raise RuntimeError,
          "Wrong number of arguments passed to `#{fn_name}`; " +
          "got #{args.count}, expected #{num_args}."
  end
end

.hash_map(values) ⇒ Object 



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# File 'lib/rubylisp/types.rb', line 123

def hash_map(values)
  if values.size.odd?
    raise ParseError, "A hash-map must contain an even number of forms."
  else
    Hamster::Hash[values.each_slice(2).to_a]
  end
end

.list(values) ⇒ Object 



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# File 'lib/rubylisp/types.rb', line 135

def list(values)
  values.to_list
end

.list?(x) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubylisp/types.rb', line 139

def list?(x)
  x.is_a? Hamster::List
end

.map?(x) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubylisp/types.rb', line 131

def map?(x)
  x.is_a? Hamster::Hash
end

.sequential?(x) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubylisp/types.rb', line 155

def sequential?(x)
  list?(x) || vector?(x)
end

.vec(values) ⇒ Object 



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# File 'lib/rubylisp/types.rb', line 143

def vec(values)
  Hamster::Vector.new(values)
end

.vector(*values) ⇒ Object 



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# File 'lib/rubylisp/types.rb', line 147

def vector(*values)
  Hamster::Vector.new(values)
end

.vector?(x) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubylisp/types.rb', line 151

def vector?(x)
  x.is_a? Hamster::Vector
end