   if (typeof xs === "undefined" || xs === null) {
     throw new Error('Pattern matching required sequence got undefined');
   }
-  if (xs.length != null) {
+  if (xs.length !== null) {
     if (i >= xs.length) {
       throw new Error('Pattern matching required a list of size at least ' + (i + 1));
     }
     return xs[i];
   }
-  if (i == 0) {
+  if (i === 0) {
     return xs.head;
   }
   return $sequenceAt(i - 1, xs.tail);

    callCompile
  else
    # log "Not handled", expression
    throw "Not handled expression in expressionCompile"
  ) ctx, expression

# -- This was used to use compiled results from some parent macro while
#    compiling as something else

astizeExpression = (source) ->
  parentize astize tokenize source

astizeExpressionWithWrapper = (source) ->
  parentize astize tokenize "(#{source})", -1


# end of API

