diff --git a/src/query-parser/types.js b/src/query-parser/types.js
index 1e2fe82..e84de34 100644
--- a/src/query-parser/types.js
+++ b/src/query-parser/types.js
@@ -1,4 +1,4 @@
-import { assocPath, curry, identity, is, last, mergeRightDeep, path } from '../fn.js'
+import { curry, is, last, mergeRightDeep, path } from '../fn.js'
 import { Stream } from '../stream.js'
 
 class Value {
@@ -97,11 +97,11 @@ export class Function {
 
   #pop(stack) {
     const result = []
-    const len = stack.length - 1
-    const n = Math.min(this.length, len)
+    let n = Math.min(this.length, stack.length)
 
-    for(let i = len; i >= len - n; i--) {
+    while(n > 0) {
       result.push(stack.pop())
+      n--
     }
 
     result.reverse()
@@ -122,14 +122,14 @@ const Associativity = Object.freeze({
 export class Operator extends Function {
   constructor(name, fn, priority, associativity = Associativity.Left, length = fn.length) {
     super(name, fn, length)
-    this.priority = priority
+    this.precedence = priority
     this.associativity = associativity
   }
 
   compare(other) {
-    if (other.priority > this.priority) {
+    if (other.precedence < this.precedence) {
       return 1
-    } else if (other.priority === this.priority) {
+    } else if (other.precedence === this.precedence) {
       if (this.associativity === Associativity.Left) {
         return 1
       } else {
@@ -185,9 +185,10 @@ export class Filter {
       const next = stream.next()
       if (is(Function, next)) {
         if (is(Operator, next)) {
-          const ops = this.#takeUntil(op => leftParen(op) && next.compare(op) <= 0, operators)
+          const ops = this.#takeWhile(op => !leftParen(op) && next.compare(op) > 0, operators)
           output.push.apply(output, ops)
         }
+
         operators.push(next)
       } else if (comma(next)) {
         output.push.apply(output, this.#takeUntil(leftParen, operators))
@@ -196,9 +197,11 @@ export class Filter {
       } else if (rightParen(next)) {
         const ops = this.#takeUntil(leftParen, operators)
         output.push.apply(output, ops)
+
         if (!leftParen(operators.pop())) {
           throw new SyntaxError('mismatched parenthesis')
         }
+
         if (is(Function, last(operators))) {
           output.push(operators.pop())
         }
@@ -226,13 +229,13 @@ export class Filter {
         const next = stream.next()
         if (is(Operator, next)) {
           const result = next.apply(stack)
-          stack.unshift(result)
+          stack.push(result)
         } else {
           stack.push(next)
         }
       }
 
-      return stack.every(identity)
+      return stack[0]
     })
   }
 }
diff --git a/src/stream.js b/src/stream.js
index b115948..36e3c7e 100644
--- a/src/stream.js
+++ b/src/stream.js
@@ -40,7 +40,7 @@ export class Iterator {
     let accumulator = []
 
     for (let i = 0; i < n; i++) {
-      if(this.done()) {
+      if (this.done()) {
         break
       }
       accumulator.push(this.next())
@@ -49,10 +49,37 @@ export class Iterator {
     return accumulator
   }
 
+  takeWhile(fn) {
+    const accumulator = []
+
+    while (!this.done() || fn(this.peek())) {
+      accumulator.push(this.next())
+    }
+
+    return accumulator
+  }
+
+  takeUntil(fn) {
+    return this.takeWhile(x => !fn(x))
+  }
+
   drop(n) {
     this.take(n)
     return this
   }
+
+  dropWhile(fn) {
+    while(!this.done() || fn(this.peek())) {
+      this.next()
+    }
+
+    return this
+  }
+
+  dropUntil(fn) {
+    this.dropWhile(x => !fn(x))
+    return this
+  }
 }
 
 class ArrayIterator extends Iterator {
diff --git a/tests/query.test.js b/tests/query.test.js
index 17c9199..ab1af09 100644
--- a/tests/query.test.js
+++ b/tests/query.test.js
@@ -121,11 +121,17 @@ describe('query', () => {
         )
 
         assert.deepEqual(
-            query('MATCH (e, h:Health) WHERE h.max = 50 OR h.current < 50 RETURN e, h.max AS maxHealth', engine).unwrap(),
-            [
-                { e: 12, maxHealth: 50 },
-                { e: 13, maxHealth: 50 }
-            ]
+           query('MATCH (e, h:Health) WHERE h.max = 50 OR h.current > 45 RETURN e, h.max AS maxHealth', engine).unwrap(),
+           [
+               { e: 12, maxHealth: 50 },
+               { e: 13, maxHealth: 50 }
+           ]
+        )
+        assert.deepEqual(
+           query('MATCH (e, :Player, h:Health) WHERE (h.max = 50 OR h.current > 45) AND e = 12 RETURN e, h.max AS maxHealth', engine).unwrap(),
+           [
+               { e: 12, maxHealth: 50 }
+           ]
         )
     })
 })