Running s-expressions from File

Question

I have a sexp in a file and i want to read in and then run it in ruby. Whenever I try to run it, it tells me SexpTypeError,

exp must be a Sexp, was String:

Is there a way to run the Sexp from file?

I am using the ruby2ruby gem and ruby_parser gems.

I've tried on Windows 10, ruby 2.6. I've tried parsing it after reading it, but it replicates the s-expression that i have in file which does not work.

    ruby      = "def a\n  puts 'A'\nend\n\ndef b\n  a\nend\na"
    parser    = RubyParser.new
    ruby2ruby = Ruby2Ruby.new
    sexp      = parser.process(ruby)
    from_file =nil

    File.open('jkl', 'wb')do |file|
        file.write(sexp)
    end
    File.open('jkl', 'rb') do |fp|
       from_file = fp.read()
    end
    eval ruby2ruby.process(from_file)

I would like for the code to run giving the output "A"

score 0 · Accepted Answer · answered Aug 01 '19 at 07:29

You have to transform the string into sexp back. E. g. instance_eval would do.

require 'ruby_parser'
require 'ruby2ruby'

ruby = "def a\n  puts 'A'\nend\n\ndef b\n  a\nend\na"
parser = RubyParser.new
ruby2ruby = Ruby2Ruby.new
sexp = parser.process(ruby)

File.open('jkl', 'wb') { |file| file.write(sexp) }
from_file = File.open('jkl', 'rb', &:read)

#                      ⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓    
eval ruby2ruby.process(instance_eval(from_file))

b()
#⇒ A

Running s-expressions from File

1 Answers1