ruby/step1_read_print.rb


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require "readline"
require "types"
require "reader"
require "printer"

# read
def READ(str)
    return read_str(str)
end

# eval
def EVAL(ast, env)
    return ast
end

# print
def PRINT(exp)
    return _pr_str(exp, true)
end

# repl
def REP(str)
    return PRINT(EVAL(READ(str), {}))
end

while line = Readline.readline("user> ", true)
    begin
        puts REP(line)
    rescue Exception => e
        puts "Error: %{e}" 
    end
end