fix: do not memoize calls containing lambdas calling segments (#944)

- do not memoize calls, if lambdas are referencing segment code to
ensure correctness

---------

Co-authored-by: megalinter-bot <[email protected]>
Co-authored-by: Lars Reimann <[email protected]>

packages/safe-ds-lang/src/language/generation/safe-ds-python-generator.ts

@@ -1,4 +1,4 @@
-import { AstUtils, LangiumDocument, TreeStreamImpl, URI } from 'langium';
+import { AstNode, AstUtils, LangiumDocument, TreeStreamImpl, URI } from 'langium';
 import {
     CompositeGeneratorNode,
     expandToNode,
@@ -16,6 +16,7 @@ import { TextDocument } from 'vscode-languageserver-textdocument';
 import { groupBy, isEmpty } from '../../helpers/collections.js';
 import { SafeDsAnnotations } from '../builtins/safe-ds-annotations.js';
 import {
+    isSdsAbstractCall,
     isSdsAbstractResult,
     isSdsAssignment,
     isSdsBlockLambda,
@@ -968,7 +969,36 @@ export class SafeDsPythonGenerator {
     private isMemoizableCall(expression: SdsCall): boolean {
         const impurityReasons = this.purityComputer.getImpurityReasonsForExpression(expression);
         // If the file is not known, the call is not memoizable
-        return !impurityReasons.some((reason) => !(reason instanceof FileRead) || reason.path === undefined);
+        return (
+            !impurityReasons.some((reason) => !(reason instanceof FileRead) || reason.path === undefined) &&
+            !this.doesCallContainLambdaReferencingSegment(expression)
+        );
+    }
+
+    private doesCallContainLambdaReferencingSegment(expression: SdsCall): boolean {
+        return getArguments(expression).some((arg) => {
+            if (isSdsExpressionLambda(arg.value)) {
+                return this.containsSegmentCall(arg.value.result);
+            } else if (isSdsBlockLambda(arg.value)) {
+                return this.containsSegmentCall(arg.value.body);
+            } else {
+                /* c8 ignore next 2 */
+                return false;
+            }
+        });
+    }
+
+    private containsSegmentCall(node: AstNode | undefined): boolean {
+        if (!node) {
+            /* c8 ignore next 2 */
+            return false;
+        }
+        return AstUtils.streamAst(node)
+            .filter(isSdsAbstractCall)
+            .some((call) => {
+                const callable = this.nodeMapper.callToCallable(call);
+                return isSdsSegment(callable);
+            });
     }
 
     private generateMemoizedCall(

packages/safe-ds-lang/tests/resources/generation/runner integration/expressions/call/generated/tests/generator/callWithRunnerIntegration/gen_input.py

@@ -12,6 +12,12 @@
 def __gen_null_safe_call(receiver: Any, callable: Callable[[], __gen_T]) -> __gen_T | None:
     return callable() if receiver is not None else None
 
+# Segments ---------------------------------------------------------------------
+
+def segment_a(a):
+    __gen_yield_result = (a) * (2)
+    return __gen_yield_result
+
 # Pipelines --------------------------------------------------------------------
 
 def test():
@@ -32,3 +38,20 @@ def test():
     __gen_null_safe_call(j, lambda: 'abc'.j(123))
     __gen_null_safe_call(k, lambda: k(456, 1.23))
     f(safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.readFile", readFile, [], [safeds_runner.file_mtime('a.txt')]))
+    f(l(lambda a: segment_a(a)))
+    f(l(lambda a: (3) * (segment_a(a))))
+    f(l(lambda a: safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.m", m, [(3) * (segment_a(a))], [])))
+    f(l(lambda a: (3) * (safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.m", m, [safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.m", m, [(3) * (segment_a(a))], [])], []))))
+    def __gen_block_lambda_0(a):
+        __gen_block_lambda_result_result = segment_a(a)
+        return __gen_block_lambda_result_result
+    f(l(__gen_block_lambda_0))
+    def __gen_block_lambda_1(a):
+        __gen_block_lambda_result_result = safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.m", m, [segment_a(a)], [])
+        return __gen_block_lambda_result_result
+    f(l(__gen_block_lambda_1))
+    f(safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.l", l, [lambda a: (3) * (a)], []))
+    def __gen_block_lambda_2(a):
+        __gen_block_lambda_result_result = (3) * (safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.m", m, [a], []))
+        return __gen_block_lambda_result_result
+    f(safeds_runner.memoized_call("tests.generator.callWithRunnerIntegration.l", l, [__gen_block_lambda_2], []))

packages/safe-ds-lang/tests/resources/generation/runner integration/expressions/call/input.sdstest

@@ -24,6 +24,12 @@ fun j(param: Any?, param2: Any?)
 @PythonCall("k($param2, $param)")
 fun k(param: Any?, param2: Any?)
 
+@Pure
+fun l(param: (a: Int) -> result: Int) -> result: Int
+
+@Pure
+fun m(param: Int) -> result: Int
+
 @Impure([ImpurityReason.FileReadFromConstantPath("a.txt")])
 fun readFile() -> content: String
 
@@ -47,4 +53,16 @@ pipeline test {
     k?(1.23, 456);
 
     f(readFile());
+    f(l((a) -> segment_a(a)));
+    f(l((a) -> 3 * segment_a(a)));
+    f(l((a) -> m(3 * segment_a(a))));
+    f(l((a) -> 3 * m(m(3 * segment_a(a)))));
+    f(l((a) {yield result = segment_a(a); }));
+    f(l((a) {yield result = m(segment_a(a)); }));
+    f(l((a) -> 3 * a));
+    f(l((a) {yield result = 3 * m(a); }));
+}
+
+segment segment_a(a: Int) -> result: Int {
+    yield result = a * 2;
 }