simplify expressions that could be type-casts

python/ql/lib/semmle/python/Comment.qll

@@ -40,7 +40,7 @@ class Comment extends @py_comment {
 
 private predicate comment_block_part(Comment start, Comment part, int i) {
   not exists(Comment prev | prev.getFollowing() = part) and
-  exists(Comment following | part.getFollowing() = following) and
+  exists(part.getFollowing()) and
   start = part and
   i = 1
   or

python/ql/lib/semmle/python/Function.qll

@@ -18,7 +18,7 @@ class Function extends Function_, Scope, AstNode {
   override Scope getScope() { result = this.getEnclosingScope() }
 
   /** Whether this function is declared in a class */
-  predicate isMethod() { exists(Class cls | this.getEnclosingScope() = cls) }
+  predicate isMethod() { this.getEnclosingScope() instanceof Class }
 
   /** Whether this is a special method, that is does its name have the form `__xxx__` (except `__init__`) */
   predicate isSpecialMethod() {

python/ql/lib/semmle/python/Variables.qll

@@ -57,7 +57,7 @@ class LocalVariable extends Variable {
   override string toString() { result = "Local Variable " + this.getId() }
 
   /** Whether this variable is a parameter */
-  override predicate isParameter() { exists(Parameter p | this.getAnAccess() = p) }
+  override predicate isParameter() { this.getAnAccess() instanceof Parameter }
 
   /** Holds if this variable is the first parameter of a method. It is not necessarily called "self" */
   override predicate isSelf() {
@@ -87,7 +87,7 @@ class NameLocalVariable extends LocalVariable {
 
 /** A global (module-level) variable */
 class GlobalVariable extends Variable {
-  GlobalVariable() { exists(Module m | m = this.getScope()) }
+  GlobalVariable() { this.getScope() instanceof Module }
 
   override string toString() { result = "Global Variable " + this.getId() }
 }

python/ql/lib/semmle/python/dataflow/new/internal/PrintNode.qll

@@ -67,6 +67,6 @@ string prettyNodeForInlineTest(DataFlow::Node node) {
   )
   or
   not exists(node.asExpr()) and
-  not exists(Expr e | e = node.(DataFlow::PostUpdateNode).getPreUpdateNode().asExpr()) and
+  not exists(node.(DataFlow::PostUpdateNode).getPreUpdateNode().asExpr()) and
   result = node.toString()
 }

python/ql/lib/semmle/python/pointsto/PointsTo.qll

@@ -916,7 +916,7 @@ private module InterModulePointsTo {
   private predicate exportsSubmodule(Folder folder, string name) {
     name.regexpMatch("\\p{L}(\\p{L}|\\d|_)*") and
     (
-      exists(Folder child | child = folder.getChildContainer(name))
+      folder.getChildContainer(name) instanceof Folder
       or
       exists(folder.getFile(name + ".py"))
     )

python/ql/lib/semmle/python/types/Exceptions.qll

@@ -83,7 +83,7 @@ class RaisingNode extends ControlFlowNode {
         result = this.innateException_objectapi()
       )
       or
-      not exists(ExceptFlowNode except | except = this.getAnExceptionalSuccessor()) and
+      not this.getAnExceptionalSuccessor() instanceof ExceptFlowNode and
       sequence_or_mapping(this) and
       result = theLookupErrorType()
       or
@@ -110,7 +110,7 @@ class RaisingNode extends ControlFlowNode {
         result = this.innateException()
       )
       or
-      not exists(ExceptFlowNode except | except = this.getAnExceptionalSuccessor()) and
+      not this.getAnExceptionalSuccessor() instanceof ExceptFlowNode and
       sequence_or_mapping(this) and
       result = ClassValue::lookupError()
       or

python/ql/lib/semmle/python/xml/XML.qll

@@ -233,7 +233,7 @@ class XMLElement extends @xmlelement, XMLParent, XMLLocatable {
   XMLAttribute getAttribute(string name) { result.getElement() = this and result.getName() = name }
 
   /** Holds if this XML element has an attribute with the specified `name`. */
-  predicate hasAttribute(string name) { exists(XMLAttribute a | a = this.getAttribute(name)) }
+  predicate hasAttribute(string name) { exists(this.getAttribute(name)) }
 
   /** Gets the value of the attribute with the specified `name`, if any. */
   string getAttributeValue(string name) { result = this.getAttribute(name).getValue() }

python/ql/src/Statements/MismatchInMultipleAssignment.ql

@@ -46,7 +46,7 @@ predicate mismatched_tuple_rhs(Assign a, int lcount, int rcount, Location loc) {
     lcount = len(l) and
     rcount = r.length() and
     lcount != rcount and
-    not exists(Starred s | l.getAnItem() = s)
+    not l.getAnItem() instanceof Starred
   )
 }
 

python/ql/src/Variables/UndefinedExport.ql

@@ -49,7 +49,7 @@ predicate mutates_globals(ModuleValue m) {
       or
       // In Python 3.8, Enum._convert_ is implemented using a metaclass, and our points-to
       // analysis doesn't handle that well enough. So we need a special case for this
-      not exists(Value enum_convert | enum_convert = enum_class.attr("_convert")) and
+      not exists(enum_class.attr("_convert")) and
       exists(CallNode call | call.getScope() = m.getScope() |
         call.getFunction().(AttrNode).getObject(["_convert", "_convert_"]).pointsTo() = enum_class
       )

python/ql/src/Variables/UndefinedGlobal.ql

@@ -68,7 +68,7 @@ predicate undefined_use_in_function(Name u) {
 
 predicate undefined_use_in_class_or_module(Name u) {
   exists(GlobalVariable v | u.uses(v)) and
-  not exists(Function f | u.getScope().getScope*() = f) and
+  not u.getScope().getScope*() instanceof Function and
   exists(SsaVariable var | var.getAUse().getNode() = u | var.maybeUndefined()) and
   not guarded_against_name_error(u) and
   not exists(ModuleValue m | m.getScope() = u.getEnclosingModule() | m.hasAttribute(u.getId())) and

python/ql/src/analysis/Efficiency.ql

@@ -8,7 +8,7 @@ import semmle.python.pointsto.PointsTo
 import semmle.python.pointsto.PointsToContext
 
 predicate trivial(ControlFlowNode f) {
-  exists(Parameter p | p = f.getNode())
+  f.getNode() instanceof Parameter
   or
   f instanceof NameConstantNode
   or