It works! Next up: primituves such as all()

gelly.pil

@@ -12,7 +12,7 @@ void main(Array<String> args) {
   //evalInit();
   String input = null;
   println("Welcome to gelly, type :q to quit.");
-  var s = new Strategy(new Map<String, StrategyDef>(), new Map<String, Term>());
+  var s = new Strategy(new Map<String, StrategyDef>(), new Map<String, ClosureStrategyDef>(), new Map<String, Term>());
   if(s.evalString(":import \"test.g\"")) {
     println(s.currentTerm.toIndentedString(0));
   } else {

rewrite.pil

@@ -54,13 +54,26 @@ class gelly::rewrite::StrategyDef {
   }
 }
 
+class gelly::rewrite::ClosureStrategyDef {
+  Term t = null;
+  Strategy parent = null;
+
+  new(Strategy parent, Term t) {
+    this.parent = parent;
+    this.t = t;
+  }
+}
+
 class gelly::rewrite::Strategy {
   Term currentTerm = new EmptyTerm();
   Map<String, Term> bindings = null;
   Map<String, StrategyDef> strategies = null;
+  Map<String, ClosureStrategyDef> closureStrategies = null;
+  Strategy parent = null;
 
-  new(Map<String, StrategyDef> strategies, Map<String, Term> bindings) {
+  new(Map<String, StrategyDef> strategies, Map<String, ClosureStrategyDef> closureStrategies, Map<String, Term> bindings) {
     this.strategies = strategies;
+    this.closureStrategies = closureStrategies;
     this.bindings = bindings;
   }
 

test.g

@@ -2,12 +2,15 @@ strategy simplify()[] {
   ?[ m_x * 1 ];
   ![ m_x ]
 };
+strategy simplify2()[] {
+  ?[ m_x + 0 ];
+  ![ m_x ]
+};
 strategy try(s)[] {
   s <+ id
 };
 strategy repeat(s)[] {
-  debug;
   try(s; repeat(s))
 };
-![ 8 * 3 * 1 * 1 * 1 * 1];
-repeat(simplify)
+![ 8 * 3 * 1 * 1 * 1 * 1 + 0];
+repeat(simplify <+ simplify2)