!7

srecord ToParse(O text) {}
srecord StarPattern(O text) {}
srecord QuotedString(O text) {}
srecord PossibleReplacement(O a, O b) {}

cprint {
  delegate TransformationTrail to TransformersOnObjects.
  transient new TransformersOnObjects too;
  switchable long maxSteps = 1000;
  
  transient F1 starPatternWrapper, quotedStringMaker;

  start-thread {
    too.autoUnpackIterables = false;
    
    S ruleText = [[LineByUser("a * is something like *") => Assumption("* is a noun")]];
    too.add(ToParse(ruleText));
    
    // unpack ToParse
    too.addTransformer(func(ToParse x) { x.text });

    too.addTransformer(f<S, O> splitAtDoubleArrow_pair,
      func(Pair p) -> joinPair(" => ", p));
    too.addTransformer(f<S, O> parseFunctionCall, func(Pair<S, LS> x) { unparseFunctionCall(x) });
    too.addTransformer(f<S, O> unquote, f<S, S> quote);
    too.addTransformer(f<Pair, O> pairA, (p, o) -> replacePairA((Pair) p, o));
    too.addTransformer(f<Pair, O> pairB, (p, o) -> replacePairB((Pair) p, o));
    
    // TODO: generalize to more elements
    too.addTransformer(
      f<L, O> first,
      (list, element) -> cloneListReplacingElementAtIndex((L) list, 0, element));
    too.addTransformer(f<L, O> second, (list, element) -> cloneListReplacingElementAtIndex((L) list, 1, element));
    
    //too.addTransformer(f<S, Bool> isStarPattern);
    
    // Suggest enclosing a star pattern string with StarPattern()
    too.addTransformer(starPatternWrapper = func(QuotedString s) {
      s.text instanceof S && isStarPattern((S) s.text) ? StarPattern(s.text) : null
    });
    
    too.addTransformer(quotedStringMaker = func(S s) { isQuoted(s) ? QuotedString(unquote(s)) : null },
      // The backtransformer may take a replacement thing
      // (so e.g. an instance of StarPattern). In that case
      // we just put it in verbatim
      func(O o) { o instanceof QuotedString ? quote(o/QuotedString.text) : o });
    
    // Reintegrate replaced star patterns into rule text
    too.addTransformer(func(StarPattern s) {
      O madeFrom = too.getTrailBy(s, starPatternWrapper).argument;
      ret PossibleReplacement(madeFrom, s);
    });
    
    // Same with QuotedString
    too.addTransformer(func(QuotedString s) {
      O madeFrom = too.getTrailBy(s, quotedStringMaker).argument;
      ret PossibleReplacement(madeFrom, s);
    });
    
    too.addTransformer(func(PossibleReplacement r) {
      replaceInSource(r.a, r.b);
      null;
    });
      
    stepAllWithStats(too, maxSteps);
    too.printWithTrails();
    print();
    too.printTransformers();
  }
  
  // replace a in b inside of where a came from
  void replaceInSource(O a, O b) {
    print(formatFunctionCall replaceInSource(a, b));
    
    // Find trails of a
    Cl<TransformationTrail> trails2 = too.getTrails(a);
    
    fOr (TransformationTrail trail2 : trails2) {
      IF2 back = too.getBackTransformer(trail2.transformer);
      print("  Path back: " + trail2);
      if (back == null) print("NO BACK TRANSFORMER for " + trail2.transformer); else {
        // Backtransform b (if possible) and put in pool
        O c = callFIfActuallyCallable(back, trail2.argument, b);
        if (c == null) continue;
        //print("  Made: " + sfu(c));
        print("  Transformed " + sfu(trail2.argument) + " into " + sfu(c));
        too.addObject(c, "replaceInSource");
        
        // TODO: Follow up with more replacements ?
        too.addObject(PossibleReplacement(trail2.argument, c), "replaceInSource");
      }
    }
  }
}