Apply the patches from ohmjs#465 to fix indentation

See ohmjs#465 (comment)

This changes memoization some so it can consume dedents

packages/ohm-js/src/MatchState.js

@@ -1,3 +1,4 @@
+import { StringBuffer } from './common.js';
 import {InputStream} from './InputStream.js';
 import {MatchResult} from './MatchResult.js';
 import {PosInfo} from './PosInfo.js';
@@ -234,10 +235,25 @@ export class MatchState {
       const actuals = app ? app.args : [];
       expr = expr.substituteParams(actuals);
     }
-    return (
-      this.getMemoizedTraceEntry(pos, expr) ||
-      new Trace(this.input, pos, this.inputStream.pos, expr, succeeded, bindings, this.trace)
-    );
+    const memoTrace = this.getMemoizedTraceEntry(pos, expr)
+    let indentsLessThanPos = 0
+    let indentsLessThanInputPos = 0
+    if (!memoTrace) {
+      const input = new StringBuffer()
+      for (let i = 0; i < this.input.length; i++) {
+        if (this.inputStream._indentationAt(i) !== 0) {
+          for (let numPlaces = this.inputStream._indentationAt(i); numPlaces !== 0; numPlaces += (numPlaces < 0 ? 1 : -1)) {
+            input.append(numPlaces < 0 ? "\u21e6" : "\u21e8")
+            if (i < pos) indentsLessThanPos += 1;
+            if (i < this.inputStream.pos) indentsLessThanInputPos += 1;
+          }
+        }
+        input.append(this.inputStream.source[i])
+      }
+      return new Trace(input.contents(), pos + indentsLessThanPos, this.inputStream.pos + indentsLessThanInputPos, expr, succeeded, bindings, this.trace)
+    } else {
+      return memoTrace;
+    }
   }
 
   isTracing() {

packages/ohm-js/src/pexprs-eval.js

@@ -232,7 +232,7 @@ pexprs.Apply.prototype.handleCycle = function(state) {
   const memoKey = this.toMemoKey();
   let memoRec = posInfo.memo[memoKey];
 
-  if (currentLeftRecursion && currentLeftRecursion.headApplication.toMemoKey() === memoKey) {
+  if (memoRec && currentLeftRecursion && currentLeftRecursion.headApplication.toMemoKey() === memoKey) {
     // We already know about this left recursion, but it's possible there are "involved
     // applications" that we don't already know about, so...
     memoRec.updateInvolvedApplicationMemoKeys();
@@ -275,7 +275,7 @@ pexprs.Apply.prototype.reallyEval = function(state) {
   let memoRec;
 
   if (state.doNotMemoize) {
-    state.doNotMemoize = false;
+    // state.doNotMemoize = false;
   } else if (isHeadOfLeftRecursion) {
     value = this.growSeedResult(body, state, origPos, currentLR, value);
     origPosInfo.endLeftRecursion();
@@ -307,7 +307,7 @@ pexprs.Apply.prototype.reallyEval = function(state) {
 
   // Record trace information in the memo table, so that it is available if the memoized result
   // is used later.
-  if (state.isTracing() && memoRec) {
+  if (state.isTracing() && memoRec && !state.doNotMemoize) {
     const entry = state.getTraceEntry(origPos, this, succeeded, succeeded ? [value] : []);
     if (isHeadOfLeftRecursion) {
       common.assert(entry.terminatingLREntry != null || !succeeded);