Python: small refactor

python/ql/src/semmle/python/Function.qll

@@ -39,6 +39,12 @@ class Function extends Function_, Scope, AstNode {
     exists(YieldFrom y | y.getScope() = this)
   }
 
+  /**
+   * Whether this is a lambda.
+   * We detect this by comparing its name to the one the extractor gives to lambdas.
+   */
+  predicate isLambda() { this.getName() = "lambda" }
+
   /** Whether this function is declared in a class and is named `__init__` */
   predicate isInitMethod() { this.isMethod() and this.getName() = "__init__" }
 

python/ql/src/semmle/python/dataflow/new/internal/DataFlowPrivate.qll

@@ -499,12 +499,11 @@ import ArgumentPassing
 newtype TDataFlowCallable =
   TCallableValue(CallableValue callable) {
     callable instanceof FunctionValue and
-    // TODO: push into FunctionValue
-    not callable.(FunctionValue).getOrigin().getNode() instanceof Lambda
+    not callable.(FunctionValue).isLambda()
     or
     callable instanceof ClassValue
   } or
-  TLambda(Function lambda) { lambda.getName() = "lambda" } or
+  TLambda(Function lambda) { lambda.isLambda() } or
   TModule(Module m)
 
 /** Represents a callable. */

python/ql/src/semmle/python/objects/ObjectAPI.qll

@@ -720,6 +720,9 @@ abstract class FunctionValue extends CallableValue {
 
   /** Gets a class that this function may return */
   abstract ClassValue getAnInferredReturnType();
+
+  /** Wheter this is a lambda function */
+  predicate isLambda() { this.getOrigin().getNode() instanceof Lambda }
 }
 
 /** Class representing Python functions */