OLD-Peg Diagram
===============

This anayse/design(?) date from  around 2021/2022

.. UML::

   @startuml

   package _base {

   abstract AST_BASE {
     -_parse_tree
     +position()
     +position_end()
     ~serialize()
   }

   class ID {
     +name
     #validate_or_raise()
   }

   ID  =|> AST_BASE
   }

   package MixIns  #Gray {

     class MixIn_value_attribute<MixIn> {
     _value
     value()
     }

     class MixIn_expr_attribute<MixIn> {
     _expr
     expr()
     }

     class MixIn_children_tuple<MixIn> {
      _children :Tuple
     __len__()
     __getitem__()
     __iter__()
     }
   }

   package Peg #0077ff {

   abstract PEG
   AST_BASE <|== PEG



   abstract Terminal
   PEG                   <|==   Terminal
   MixIn_value_attribute <|...  Terminal
   Terminal              <|==   StrTerm
   Terminal              <|==   RexExpTerm
   Terminal              <|==   Number

   abstract    Markers #Orange
   annotation  EOF     #Orange
   PEG         <|==    Markers
   Markers     <|==    EOF

   abstract NonTerminal
   PEG          <|== NonTerminal
   abstract Expression
   NonTerminal  <|== Expression

   class Setting  {
    name  : ID
    value
   }
   PEG      <|==  Setting

   class Rule {
     name  :ID
     expr  :[] Expression
   }
   NonTerminal  <|==  Rule

   interface Rules
   PEG                   <|==    Rules
   MixIn_children_tuple  <|...  Rules
   Rules                 <|==    ParseRules
   Rules                 <|==    Settings

   class Grammar {
     +all_rules    :Rules
     -parse_rules  :ParseRules
     -settings     :Settings
   }
   NonTerminal  <|== Grammar


   abstract Group
   Expression            <|== Group
   Group                 <|== UnorderedGroup
   MixIn_expr_attribute  <|... UnorderedGroup
   abstract Quantity
   Group                   <|==    Quantity
   MixIn_expr_attribute    <|...    Quantity
   Expression              <|==    Sequence
   MixIn_children_tuple    <|...  Sequence

   Expression             <|==   OrderedChoice
   MixIn_children_tuple   <|...  OrderedChoice

   class Optional   << (?, #0077ff) >>
   Quantity          <|==   Optional
   class ZeroOrMore << (*, #0077ff) >>
   Quantity          <|==   ZeroOrMore
   class OneOrMore  << (+, #0077ff) >>
   Quantity          <|==   OneOrMore

   abstract Predicate
   Expression             <|==   Predicate
   MixIn_expr_attribute   <|... Predicate
   class AndPredicate << (&, #0077ff) notconsuming >>
   Predicate               <|== AndPredicate
   class NotPredicate << (! ,#0077ff) not consuming >>
   Predicate               <|== NotPredicate

   }
   @enduml