Revert "Allow expressions as arguments"

This reverts commit 3578f2b70312e681b11db97e6ead8997e2dd7d3c.

2 files changed, 22 insertions, 14 deletions

diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/ExpressionFunction.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/ExpressionFunction.java
index b97c8316c9b..9f900ffed36 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/ExpressionFunction.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/ExpressionFunction.java
@@ -3,10 +3,7 @@ package com.yahoo.searchlib.rankingexpression;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.yahoo.searchlib.rankingexpression.rule.ConstantNode;
 import com.yahoo.searchlib.rankingexpression.rule.ExpressionNode;
-import com.yahoo.searchlib.rankingexpression.rule.FunctionNode;
-import com.yahoo.searchlib.rankingexpression.rule.ReferenceNode;
 import com.yahoo.searchlib.rankingexpression.rule.SerializationContext;
 import com.yahoo.tensor.TensorType;
 import com.yahoo.text.Utf8;
@@ -134,16 +131,7 @@ public class ExpressionFunction {
     public Instance expand(SerializationContext context, List<ExpressionNode> argumentValues, Deque<String> path) {
         Map<String, String> argumentBindings = new HashMap<>();
         for (int i = 0; i < arguments.size() && i < argumentValues.size(); ++i) {
-            String key = arguments.get(i);
-            ExpressionNode expr = argumentValues.get(i);
-            String binding = expr.toString(new StringBuilder(), context, path, null).toString();
-
-            if ( ! (expr instanceof ReferenceNode) && ! (expr instanceof ConstantNode) && ! (expr instanceof FunctionNode) ) {
-                String funcName = "autogenerated_ranking_feature@" + Long.toHexString(symbolCode(key + "=" + binding));
-                context.addFunctionSerialization(RankingExpression.propertyName(funcName), binding);
-                binding = funcName;
-            }
-            argumentBindings.put(key, binding);
+            argumentBindings.put(arguments.get(i), argumentValues.get(i).toString(new StringBuilder(), context, path, null).toString());
         }
         context = argumentBindings.isEmpty() ? context.withoutBindings() : context.withBindings(argumentBindings);
         String symbol = toSymbol(argumentBindings);
diff --git a/searchlib/src/main/javacc/RankingExpressionParser.jj b/searchlib/src/main/javacc/RankingExpressionParser.jj
index 36b1f9627bb..09880b8dfc3 100755
--- a/searchlib/src/main/javacc/RankingExpressionParser.jj
+++ b/searchlib/src/main/javacc/RankingExpressionParser.jj
@@ -328,10 +328,30 @@ List<ExpressionNode> args() :
     ExpressionNode argument;
 }
 {
-    ( ( argument = expression() { arguments.add(argument); } ( <COMMA> argument = expression() { arguments.add(argument); } )* )? )
+    ( ( argument = arg() { arguments.add(argument); } ( <COMMA> argument = arg() { arguments.add(argument); } )* )? )
     { return arguments; }
 }
 
+// TODO: Replace use of this for function arguments with value()
+// For that to work with the current search execution framework
+// we need to generate another function for the argument such that we can replace
+// instances of the argument with the reference to that function in the same way
+// as we replace by constants/names today (this can make for some fun combinatorial explosion).
+// We should also stop doing function expansion in the toString of a function.
+// - Jon 2014-05-02
+ExpressionNode arg() :
+{
+    ExpressionNode ret;
+    String name;
+    Function fnc;
+}
+{
+    ( ret = constantPrimitive()                                          |
+      LOOKAHEAD(2) ret = feature()                                       |
+      name = identifier()              { ret = new NameNode(name);       } )
+    { return ret; }
+}
+
 ExpressionNode function() :
 {
     ExpressionNode function;