Class: Sexpistol

Inherits:
Object
  • Object
show all
Defined in:
lib/sexpistol/sexpistol.rb

Overview

This class contains our logic for parsing S-Expressions. They are turned into a native Ruby representation like:

[:def, :something [:lambda, [:a], [:do_something]]]

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#ruby_keyword_literals ⇒ Object

Returns the value of attribute ruby_keyword_literals.



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# File 'lib/sexpistol/sexpistol.rb', line 7

def ruby_keyword_literals
  @ruby_keyword_literals
end

#scheme_compatability ⇒ Object

Returns the value of attribute scheme_compatability.



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# File 'lib/sexpistol/sexpistol.rb', line 7

def scheme_compatability
  @scheme_compatability
end

Instance Method Details

#convert_ruby_keyword_literals(expression) ⇒ Object

Convert symbols corresponding to Ruby’s keyword literals into their literal forms



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# File 'lib/sexpistol/sexpistol.rb', line 19

def convert_ruby_keyword_literals(expression)
  return recursive_map(expression) do |x|
    case x
      when :'nil' then nil
      when :'true' then true
      when :'false' then false
      else x
    end
  end
end

#convert_scheme_literals(data) ⇒ Object

Convert nil, true and false into (), #t and #f for compatability with Scheme



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# File 'lib/sexpistol/sexpistol.rb', line 32

def convert_scheme_literals(data)
  return recursive_map(data) do |x|
    case x
      when nil then []
      when true then :"#t"
      when false then :"#f"
      else x
    end
   end
end

#parse_string(string) ⇒ Object

Parse a string containing an S-Expression into a nested set of Ruby arrays



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# File 'lib/sexpistol/sexpistol.rb', line 11

def parse_string(string)
  tree = SexpistolParser.new(string).parse
  return convert_ruby_keyword_literals(tree) if(@ruby_keyword_literals)
  return tree
end

#to_sexp(data) ⇒ Object

Convert a set of nested arrays back into an S-Expression



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# File 'lib/sexpistol/sexpistol.rb', line 44

def to_sexp(data)
  data = convert_scheme_literals(data) if(@scheme_compatability)
  if( data.is_a?(Array))
    mapped = data.map do |item|
      if( item.is_a?(Array))
        to_sexp(item)
      elsif item.is_a?(String)
        "\"" + item + "\""
      else
        item.to_s
      end
    end
    "(" + mapped.join(" ") + ")"
  else
    data.to_s
  end
end