1 files changed, 61 insertions, 0 deletions
diff --git a/src/main/scala/com/google/gimd/query/Query.scala b/src/main/scala/com/google/gimd/query/Query.scala
new file mode 100644
index 0000000..4251b53
--- /dev/null
+++ b/src/main/scala/com/google/gimd/query/Query.scala
@@ -0,0 +1,61 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gimd.query
+
+import com.google.gimd.{FieldSpecOne, UserType}
+
+/**
+ * Class that holds a Query AST defined for specific UserType.
+ */
+final class Query[U <: UserType[_]](val ut: U, val cond: List[Node[Boolean]]) {
+
+  def where(f: U => Node[Boolean]) = new Query[U](ut, f(ut) :: cond)
+
+}
+
+object Query {
+
+  //this alias is needed due to bug in Scala 2.7.x. It's been fixed in 2.8.0 so once we switch to it
+  //this can be removed
+  type UserType_ = UserType[_]
+
+  implicit def userType2Query[U <: UserType_](ut: U) = new Query[U](ut, Nil)
+
+  //a few conversions to Node[T]
+  implicit def fieldSpecOne2Node[T](fs: FieldSpecOne[_,T]) = FieldSpecOneNode(fs)
+  implicit def nodeOps2Node[T](ops: NodeOps[T]) = ops.leftOperand
+  implicit def const2Node[T](x: T) = ConstNode(x)
+  implicit def arbitraryPredicate2Node[T](p: Predicate[T]) = PredicateNode(p)
+
+  //a few lifts to traits that define operations one can apply to given Nodes.
+  implicit def fieldSpecOne2BooleanNodeOps(fs: FieldSpecOne[_,Boolean]) = new BooleanNodeOps {
+    val leftOperand = FieldSpecOneNode(fs)
+  }
+  implicit def fieldSpecOne2AllNodeOps[T](fs: FieldSpecOne[_,T]) = new AllNodeOps[T] {
+    val leftOperand = FieldSpecOneNode(fs)
+  }
+
+  implicit def booleanConst2BooleanNodeOps(x: Boolean) = new BooleanNodeOps {
+    val leftOperand = ConstNode(x)
+  }
+  implicit def const2AllNodeOps[T](x: T) = new AllNodeOps[T] {
+    val leftOperand = ConstNode(x)
+  }
+
+  implicit def predicate2BooleanNodeOps(p: Predicate[_]) = new BooleanNodeOps {
+    val leftOperand = PredicateNode(p)
+  }
+
+}