REPL; basic parsing

repl.rb

@@ -0,0 +1,78 @@
+# coding: utf-8
+# frozen_string_literal: true
+
+require 'readline'
+
+def run_REPL( stack )
+  Readline.completion_proc = proc do |s|
+    directory_list = Dir.glob("#{s}*")
+    if directory_list.positive?
+      directory_list
+    else
+      Readline::HISTORY.grep(/^#{Regexp.escape(s)}/)
+    end
+  end
+  Readline.completion_append_character = " "
+
+  loop do
+    input = Readline.readline( " ", true )
+    break if input == "exit"
+
+    # Remove blank lines from history
+    Readline::HISTORY.pop if input.empty?
+
+    stack = process_input( stack, input )
+
+    stack = display_stack( stack )
+  end
+end
+
+def parse_input( input )
+  splitted_input = input.split( " " )
+  parsed_input = []
+
+  regrouping = false
+  splitted_input.each do |elt|
+    if regrouping
+      partial_elt = parsed_input.pop
+      elt = "#{partial_elt} #{elt}"
+    end
+
+    if regrouping
+      regrouping = false if (elt[0] == '\'' and elt[-1] == '\'') or (elt[0] == '"' and elt[-1] == '"') or (elt[0] == '«' and elt[-1] == '»')
+    else
+      regrouping = true if elt[0] == '\'' or elt[0] == '"' or elt[0] == '«'
+    end
+
+    # 'xx' is a name (no space allowed)
+    # "xx x x xx" is a string
+    # « xx xx xx » is a program (must have inner spaces)
+
+    parsed_input << elt
+  end
+
+  parsed_input
+end
+
+def process_input( stack, input )
+  parse_input( input ).each do |elt|
+    stack << elt
+  end
+
+  stack
+end
+
+def display_stack( stack )
+  stack_size = stack.size
+  stack.each_with_index { |v, i| puts "#{stack_size - i}: #{v}"}
+
+  stack
+end
+
+def stack_init
+  stack = []
+
+  stack
+end
+
+run_REPL( stack_init )