!7

replace SimpleStatements with MatchableRecords<Prop>.
replace Env with SimpleStatements.

abstract sclass Prop implements IFieldsToList {}

static withToList record Did$HappenBefore$<A, B>(A event1, B event2) {}
static withToList record WhenDid$Happen(O event) extends Prop {}
static withToList record $HappensAtSecond$<A, B>(A event, B y) extends Prop {}

static cached L<Class<? extends Prop>> propClasses() { ret myNonAbstractClassesImplementing(Prop); }

static cached LPair<Class<? extends Prop>, S> classesAndPatterns() {
  ret map(propClasses(),
    c -> pair(dollarsToStarsAndSplitCamelCase(shortClassName(c)), c));
}

static O parseArg(S s) { ret isInteger(s) ? parseInt(s) : s; }

static Prop parseProp(S s) {
  new Matches m;
  for (Pair<Class<? extends Prop> c, S> p : classesAndPatterns()) {
    if (match(p.b, s, m))
      ret nuObject(p.a, map parseArg(m));
  }
  null;
}

p-exp {
  for (S s : tlft([[
    Did X happen before Y?
    when did Z happen
  ]]))
    print(s + " => " + parseProp(s));
}