Fix filter/map macro to be linear in time and space complexity#746

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Merged
copybara-service merged 1 commit into from
Jul 14, 2025
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Fix filter/map macro to be linear in time and space complexity #746

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11 changes: 11 additions & 0 deletions runtime/src/main/java/dev/cel/runtime/BUILD.bazel
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
exports = [":base"],
deps = [
":base",
":concatenated_list_view",
":dispatcher",
":evaluation_exception",
":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
visibility = ["//visibility:private"],
deps = [
":base_android",
":concatenated_list_view",
":dispatcher_android",
":evaluation_exception",
":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
tags = [
],
deps = [
":concatenated_list_view",
"//common:error_codes",
"//common:options",
"//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
tags = [
],
deps = [
":concatenated_list_view",
"//common:error_codes",
"//common:options",
"//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
"@maven_android//:com_google_guava_guava",
],
)

java_library(
name = "concatenated_list_view",
srcs = ["ConcatenatedListView.java"],
# used_by_android
visibility = ["//visibility:private"],
)
102 changes: 102 additions & 0 deletions runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java
View file
Open in desktop
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
* A custom list view implementation that allows O(1) concatenation of two lists. Its primary
* purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
* comprehensions that dispatch `add_list` to concat N lists together).
*
* <p>This does not support any of the standard list operations from {@link java.util.List}.
*/
final class ConcatenatedListView<E> extends AbstractList<E> {
private final List<List<? extends E>> sourceLists;
private int totalSize = 0;

ConcatenatedListView() {
this.sourceLists = new ArrayList<>();
}

ConcatenatedListView(Collection<? extends E> collection) {
this();
addAll(collection);
}

@Override
public boolean addAll(Collection<? extends E> collection) {
if (!(collection instanceof List)) {
// size() is O(1) iff it's a list
throw new IllegalStateException("addAll must be called with lists, not collections");
}

sourceLists.add((List<? extends E>) collection);
totalSize += collection.size();
return true;
}

@Override
public E get(int index) {
throw new UnsupportedOperationException("get method not supported.");
}

@Override
public int size() {
return totalSize;
}

@Override
public Iterator<E> iterator() {
return new ConcatenatingIterator();
}

/** Custom iterator to provide a flat view of all concatenated collections */
private class ConcatenatingIterator implements Iterator<E> {
private int index = 0;
private Iterator<? extends E> iterator = null;

@Override
public boolean hasNext() {
while (iterator == null || !iterator.hasNext()) {
if (index < sourceLists.size()) {
iterator = sourceLists.get(index).iterator();
index++;
} else {
return false;
}
}
return true;
}

@Override
public E next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return iterator.next();
}

@Override
public void remove() {
throw new UnsupportedOperationException("remove method not supported");
}
}
}
32 changes: 32 additions & 0 deletions runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
throws CelEvaluationException {
ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

return internalResult.value();
}

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
}
}

@SuppressWarnings("unchecked") // All type-erased elements are object compatible
private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
// ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
// under the hood. In situations where short circuiting is disabled, we don't want to evaluate
// both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
return accuValue;
}

ConcatenatedListView<Object> lv =
new ConcatenatedListView<>((List<Object>) accuValue.value());
return IntermediateResult.create(lv);
}

@SuppressWarnings("unchecked") // All type-erased elements are object compatible
private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
if ((accuValue.value() instanceof ConcatenatedListView)) {
// Materialize view back into a list to facilitate O(1) lookups.
List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

accuValue = IntermediateResult.create(copiedList);
}

return accuValue;
}

@SuppressWarnings("unchecked")
private IntermediateResult evalComprehension(
ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
} else {
accuValue = evalNonstrictly(frame, compre.accuInit());
// This ensures macros such as filter/map that uses "add_list" functions under the hood
// remain linear in time complexity
accuValue = maybeAdaptToListView(accuValue);
}
int i = 0;
for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
frame.popScope();
}

accuValue = maybeAdaptViewToList(accuValue);

frame.pushScope(Collections.singletonMap(accuVar, accuValue));
IntermediateResult result;
try {
Expand Down
7 changes: 6 additions & 1 deletion runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

/** Concatenates two lists into a new list. */
public static <E> List<E> concat(List<E> first, List<E> second) {
// TODO: return a view instead of an actual copy.
if (first instanceof ConcatenatedListView) {
// Comprehensions use a more efficient list view for performing O(1) concatenation
first.addAll(second);
return first;
}

List<E> result = new ArrayList<>(first.size() + second.size());
result.addAll(first);
result.addAll(second);
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
Fix filter/map macro to be linear in time and space complexity#746

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Sign in
to your account

 Merged

copybara-service
merged 1 commit into

from

Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Fix filter/map macro to be linear in time and space complexity#746

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
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to your account

 Merged

copybara-service
merged 1 commit into

from

Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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Commits

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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Fix filter/map macro to be linear in time and space complexity#746

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 Merged

copybara-service
merged 1 commit into

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Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

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Fix filter/map macro to be linear in time and space complexity#746

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 Merged

copybara-service
merged 1 commit into

from

Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Fix filter/map macro to be linear in time and space complexity#746

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privacy statement. We’ll occasionally send you account related emails.

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Sign in
to your account

 Merged

copybara-service
merged 1 commit into

from

Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Fix filter/map macro to be linear in time and space complexity#746

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 Merged

copybara-service
merged 1 commit into

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Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
Fix filter/map macro to be linear in time and space complexity#746

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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privacy statement. We’ll occasionally send you account related emails.

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 Merged

copybara-service
merged 1 commit into

from

Jul 14, 2025
 Merged


Fix filter/map macro to be linear in time and space complexity
#746
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Commits

Show all changes


1 commit


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11 changes: 11 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/BUILD.bazel

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -272,6 +272,7 @@ java_library(
 exports = [":base"],
 deps = [
 ":base",
 ":concatenated_list_view",
 ":dispatcher",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -306,6 +307,7 @@ cel_android_library(
 visibility = ["//visibility:private"],
 deps = [
 ":base_android",
 ":concatenated_list_view",
 ":dispatcher_android",
 ":evaluation_exception",
 ":evaluation_exception_builder",
Expand DownExpand Up@@ -398,6 +400,7 @@ cel_android_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand All@@ -419,6 +422,7 @@ java_library(
 tags = [
 ],
 deps = [
 ":concatenated_list_view",
 "//common:error_codes",
 "//common:options",
 "//common:runtime_exception",
Expand DownExpand Up@@ -1094,3 +1098,10 @@ cel_android_library(
 "@maven_android//:com_google_guava_guava",
 ],
)

java_library(
 name = "concatenated_list_view",
 srcs = ["ConcatenatedListView.java"],
 # used_by_android
 visibility = ["//visibility:private"],
)

102 changes: 102 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,102 @@
// Copyright 2025 Google LLC
//
// 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 aj
//
// https://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 dev.cel.runtime;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

/**
 * A custom list view implementation that allows O(1) concatenation of two lists. Its primary
 * purpose is to facilitate efficient accumulation of lists for later materialization. (ex:
 * comprehensions that dispatch `add_list` to concat N lists together).
 *
 * <p>This does not support any of the standard list operations from {@link java.util.List}.
 */
final class ConcatenatedListView<E> extends AbstractList<E> {
 private final List<List<? extends E>> sourceLists;
 private int totalSize = 0;

 ConcatenatedListView() {
 this.sourceLists = new ArrayList<>();
 }

 ConcatenatedListView(Collection<? extends E> collection) {
 this();
 addAll(collection);
 }

 @Override
 public boolean addAll(Collection<? extends E> collection) {
 if (!(collection instanceof List)) {
 // size() is O(1) iff it's a list
 throw new IllegalStateException("addAll must be called with lists, not collections");
 }

 sourceLists.add((List<? extends E>) collection);
 totalSize += collection.size();
 return true;
 }

 @Override
 public E get(int index) {
 throw new UnsupportedOperationException("get method not supported.");
 }

 @Override
 public int size() {
 return totalSize;
 }

 @Override
 public Iterator<E> iterator() {
 return new ConcatenatingIterator();
 }

 /** Custom iterator to provide a flat view of all concatenated collections */
 private class ConcatenatingIterator implements Iterator<E> {
 private int index = 0;
 private Iterator<? extends E> iterator = null;

 @Override
 public boolean hasNext() {
 while (iterator == null || !iterator.hasNext()) {
 if (index < sourceLists.size()) {
 iterator = sourceLists.get(index).iterator();
 index++;
 } else {
 return false;
 }
 }
 return true;
 }

 @Override
 public E next() {
 if (!hasNext()) {
 throw new NoSuchElementException();
 }
 return iterator.next();
 }

 @Override
 public void remove() {
 throw new UnsupportedOperationException("remove method not supported");
 }
 }
}

32 changes: 32 additions & 0 deletions
runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -173,6 +173,7 @@ public Object evalTrackingUnknowns(
 throws CelEvaluationException {
 ExecutionFrame frame = newExecutionFrame(resolver, functionResolver, listener);
 IntermediateResult internalResult = evalInternal(frame, ast.getExpr());

 return internalResult.value();
 }

Expand DownExpand Up@@ -896,6 +897,32 @@ private IntermediateResult evalNonstrictly(ExecutionFrame frame, CelExpr expr) {
 }
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptToListView(IntermediateResult accuValue) {
 // ListView uses a mutable reference internally. Macros such as `filter` uses conditionals
 // under the hood. In situations where short circuiting is disabled, we don't want to evaluate
 // both LHS and RHS, as evaluating LHS can mutate the accu value, which also affects RHS.
 if (!(accuValue.value() instanceof List) || !celOptions.enableShortCircuiting()) {
 return accuValue;
 }

 ConcatenatedListView<Object> lv =
 new ConcatenatedListView<>((List<Object>) accuValue.value());
 return IntermediateResult.create(lv);
 }

 @SuppressWarnings("unchecked") // All type-erased elements are object compatible
 private IntermediateResult maybeAdaptViewToList(IntermediateResult accuValue) {
 if ((accuValue.value() instanceof ConcatenatedListView)) {
 // Materialize view back into a list to facilitate O(1) lookups.
 List<Object> copiedList = new ArrayList<>((List<Object>) accuValue.value());

 accuValue = IntermediateResult.create(copiedList);
 }

 return accuValue;
 }

 @SuppressWarnings("unchecked")
 private IntermediateResult evalComprehension(
 ExecutionFrame frame, CelExpr unusedExpr, CelComprehension compre)
Expand DownExpand Up@@ -924,6 +951,9 @@ private IntermediateResult evalComprehension(
 accuValue = IntermediateResult.create(new LazyExpression(compre.accuInit()));
 } else {
 accuValue = evalNonstrictly(frame, compre.accuInit());
 // This ensures macros such as filter/map that uses "add_list" functions under the hood
 // remain linear in time complexity
 accuValue = maybeAdaptToListView(accuValue);
 }
 int i = 0;
 for (Object elem : iterRange) {
Expand All@@ -950,6 +980,8 @@ private IntermediateResult evalComprehension(
 frame.popScope();
 }

 accuValue = maybeAdaptViewToList(accuValue);

 frame.pushScope(Collections.singletonMap(accuVar, accuValue));
 IntermediateResult result;
 try {
Expand Down

7 changes: 6 additions & 1 deletion
runtime/src/main/java/dev/cel/runtime/RuntimeHelpers.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -91,7 +91,12 @@ public static boolean matches(String string, String regexp, CelOptions celOption

 /** Concatenates two lists into a new list. */
 public static <E> List<E> concat(List<E> first, List<E> second) {
 // TODO: return a view instead of an actual copy.
 if (first instanceof ConcatenatedListView) {
 // Comprehensions use a more efficient list view for performing O(1) concatenation
 first.addAll(second);
 return first;
 }

 List<E> result = new ArrayList<>(first.size() + second.size());
 result.addAll(first);
 result.addAll(second);
Expand Down