Move pkl-formatter to Java (#1514)

pkl-formatter/gradle.lockfile

@@ -24,22 +24,21 @@ org.jetbrains.kotlin:kotlin-daemon-client:2.2.21=kotlinBuildToolsApiClasspath
 org.jetbrains.kotlin:kotlin-daemon-embeddable:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,swiftExportClasspathResolvable
 org.jetbrains.kotlin:kotlin-klib-commonizer-embeddable:2.2.21=kotlinKlibCommonizerClasspath
 org.jetbrains.kotlin:kotlin-metadata-jvm:2.2.21=kotlinInternalAbiValidation
-org.jetbrains.kotlin:kotlin-native-prebuilt:2.0.21=kotlinNativeBundleConfiguration
 org.jetbrains.kotlin:kotlin-reflect:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,swiftExportClasspathResolvable
 org.jetbrains.kotlin:kotlin-script-runtime:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,swiftExportClasspathResolvable
 org.jetbrains.kotlin:kotlin-scripting-common:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest
 org.jetbrains.kotlin:kotlin-scripting-compiler-embeddable:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest
 org.jetbrains.kotlin:kotlin-scripting-compiler-impl-embeddable:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest
 org.jetbrains.kotlin:kotlin-scripting-jvm:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest
-org.jetbrains.kotlin:kotlin-stdlib-jdk7:2.2.21=apiDependenciesMetadata,compileClasspath,implementationDependenciesMetadata,runtimeClasspath,testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
+org.jetbrains.kotlin:kotlin-stdlib-jdk7:2.2.21=testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
-org.jetbrains.kotlin:kotlin-stdlib-jdk8:2.2.21=apiDependenciesMetadata,compileClasspath,implementationDependenciesMetadata,runtimeClasspath,testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
+org.jetbrains.kotlin:kotlin-stdlib-jdk8:2.2.21=testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
-org.jetbrains.kotlin:kotlin-stdlib:2.2.21=apiDependenciesMetadata,compileClasspath,implementationDependenciesMetadata,kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,runtimeClasspath,swiftExportClasspathResolvable,testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
+org.jetbrains.kotlin:kotlin-stdlib:2.2.21=kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,swiftExportClasspathResolvable,testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
 org.jetbrains.kotlin:swift-export-embeddable:2.2.21=swiftExportClasspathResolvable
 org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm:1.8.0=kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,swiftExportClasspathResolvable
 org.jetbrains.kotlinx:kotlinx-serialization-bom:1.7.3=swiftExportClasspathResolvable
 org.jetbrains.kotlinx:kotlinx-serialization-core-jvm:1.7.3=swiftExportClasspathResolvable
 org.jetbrains.kotlinx:kotlinx-serialization-core:1.7.3=swiftExportClasspathResolvable
-org.jetbrains:annotations:13.0=compileClasspath,kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,runtimeClasspath,swiftExportClasspathResolvable,testCompileClasspath,testRuntimeClasspath
+org.jetbrains:annotations:13.0=kotlinBuildToolsApiClasspath,kotlinCompilerClasspath,kotlinCompilerPluginClasspathMain,kotlinCompilerPluginClasspathTest,kotlinInternalAbiValidation,kotlinKlibCommonizerClasspath,swiftExportClasspathResolvable,testCompileClasspath,testRuntimeClasspath
 org.jspecify:jspecify:1.0.0=testCompileClasspath,testImplementationDependenciesMetadata
 org.junit.jupiter:junit-jupiter-api:6.0.3=testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
 org.junit.jupiter:junit-jupiter-engine:6.0.3=testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
@@ -50,4 +49,4 @@ org.junit.platform:junit-platform-launcher:6.0.3=testRuntimeClasspath
 org.junit:junit-bom:6.0.3=testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
 org.msgpack:msgpack-core:0.9.11=testRuntimeClasspath
 org.opentest4j:opentest4j:1.3.0=testCompileClasspath,testImplementationDependenciesMetadata,testRuntimeClasspath
-empty=annotationProcessor,compileOnlyDependenciesMetadata,intransitiveDependenciesMetadata,kotlinCompilerPluginClasspath,kotlinNativeCompilerPluginClasspath,kotlinScriptDefExtensions,signatures,sourcesJar,testAnnotationProcessor,testApiDependenciesMetadata,testCompileOnlyDependenciesMetadata,testIntransitiveDependenciesMetadata,testKotlinScriptDefExtensions
+empty=annotationProcessor,apiDependenciesMetadata,compileClasspath,compileOnlyDependenciesMetadata,implementationDependenciesMetadata,intransitiveDependenciesMetadata,kotlinCompilerPluginClasspath,kotlinNativeCompilerPluginClasspath,kotlinScriptDefExtensions,runtimeClasspath,sourcesJar,testAnnotationProcessor,testApiDependenciesMetadata,testCompileOnlyDependenciesMetadata,testIntransitiveDependenciesMetadata,testKotlinScriptDefExtensions

pkl-formatter/pkl-formatter.gradle.kts

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2025-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 plugins {
   pklAllProjects
-  pklKotlinLibrary
+  pklJavaLibrary
   pklPublishLibrary
 }
 

pkl-formatter/src/main/java/org/pkl/formatter/FormatNode.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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 at
+ *
+ *     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 org.pkl.formatter;
+
+import java.util.List;
+import java.util.Set;
+
+sealed interface FormatNode
+    permits Text,
+        Empty,
+        Line,
+        ForceLine,
+        SpaceOrLine,
+        Space,
+        Indent,
+        Nodes,
+        Group,
+        MultilineStringGroup,
+        IfWrap {
+
+  default int width(Set<Integer> wrapped) {
+    if (this instanceof Nodes n) {
+      return n.nodes().stream().mapToInt(node -> node.width(wrapped)).sum();
+    } else if (this instanceof Group g) {
+      return g.nodes().stream().mapToInt(node -> node.width(wrapped)).sum();
+    } else if (this instanceof Indent i) {
+      return i.nodes().stream().mapToInt(node -> node.width(wrapped)).sum();
+    } else if (this instanceof IfWrap iw) {
+      return wrapped.contains(iw.id()) ? iw.ifWrap().width(wrapped) : iw.ifNotWrap().width(wrapped);
+    } else if (this instanceof Text t) {
+      return t.text().length();
+    } else if (this instanceof SpaceOrLine || this instanceof Space) {
+      return 1;
+    } else if (this instanceof ForceLine || this instanceof MultilineStringGroup) {
+      return Generator.MAX;
+    } else {
+      return 0;
+    }
+  }
+}
+
+record Text(String text) implements FormatNode {}
+
+record Empty() implements FormatNode {
+  static final Empty INSTANCE = new Empty();
+}
+
+record Line() implements FormatNode {
+  static final Line INSTANCE = new Line();
+}
+
+record ForceLine() implements FormatNode {
+  static final ForceLine INSTANCE = new ForceLine();
+}
+
+record SpaceOrLine() implements FormatNode {
+  static final SpaceOrLine INSTANCE = new SpaceOrLine();
+}
+
+record Space() implements FormatNode {
+  static final Space INSTANCE = new Space();
+}
+
+record Indent(List<FormatNode> nodes) implements FormatNode {}
+
+record Nodes(List<FormatNode> nodes) implements FormatNode {}
+
+record Group(int id, List<FormatNode> nodes) implements FormatNode {}
+
+record MultilineStringGroup(int endQuoteCol, List<FormatNode> nodes) implements FormatNode {}
+
+record IfWrap(int id, FormatNode ifWrap, FormatNode ifNotWrap) implements FormatNode {}

pkl-formatter/src/main/java/org/pkl/formatter/Formatter.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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 at
+ *
+ *     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 org.pkl.formatter;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import org.pkl.parser.GenericParser;
+
+/**
+ * A formatter for Pkl files that applies canonical formatting rules.
+ *
+ * @see GrammarVersion
+ */
+public class Formatter {
+
+  private final GrammarVersion grammarVersion;
+
+  public Formatter(GrammarVersion grammarVersion) {
+    this.grammarVersion = grammarVersion;
+  }
+
+  public Formatter() {
+    this(GrammarVersion.latest());
+  }
+
+  /**
+   * Formats a Pkl file from the given file path.
+   *
+   * @param path the path to the Pkl file to format
+   * @param grammarVersion grammar compatibility version
+   * @return the formatted Pkl source code as a string
+   * @throws java.io.IOException if the file cannot be read
+   * @deprecated use {@code format(Files.readString(path))} instead
+   */
+  @Deprecated
+  public String format(Path path, GrammarVersion grammarVersion) throws IOException {
+    return new Formatter(grammarVersion).format(Files.readString(path));
+  }
+
+  /**
+   * Formats a Pkl file from the given file path.
+   *
+   * @param path the path to the Pkl file to format
+   * @return the formatted Pkl source code as a string
+   * @throws java.io.IOException if the file cannot be read
+   * @deprecated use {@code format(Files.readString(path))} instead
+   */
+  @Deprecated
+  public String format(Path path) throws IOException {
+    return format(path, GrammarVersion.latest());
+  }
+
+  /**
+   * Formats the given Pkl source code text.
+   *
+   * @param text the Pkl source code to format
+   * @param grammarVersion grammar compatibility version
+   * @return the formatted Pkl source code as a string
+   * @deprecated use {@code new Formatter(grammarVersion).format(text)} instead
+   */
+  @Deprecated
+  public String format(String text, GrammarVersion grammarVersion) {
+    return new Formatter(grammarVersion).format(text);
+  }
+
+  /**
+   * Formats the given Pkl source code text.
+   *
+   * @param text the Pkl source code to format
+   * @return the formatted Pkl source code as a string
+   */
+  public String format(String text) {
+    var sb = new StringBuilder();
+    format(text, sb);
+    return sb.toString();
+  }
+
+  /**
+   * Formats the given Pkl source code text.
+   *
+   * <p>It is the caller's responsibility to close {@code input}, and, if applicable, {@code
+   * output}.
+   *
+   * @param input the Pkl source code to format
+   * @param output the formatted Pkl source code
+   * @throws IOException if an I/O error occurs during reading or writing
+   */
+  public void format(Reader input, Appendable output) throws IOException {
+    var sb = new StringBuilder();
+    var buf = new char[8192];
+    int n;
+    while ((n = input.read(buf)) != -1) {
+      sb.append(buf, 0, n);
+    }
+    format(sb.toString(), output);
+  }
+
+  private void format(String input, Appendable output) {
+    var ast = new GenericParser().parseModule(input);
+    var formatAst = new Builder(input, grammarVersion).format(ast);
+    // force a line at the end of the file
+    var nodes = new Nodes(List.of(formatAst, ForceLine.INSTANCE));
+    new Generator(output).generate(nodes);
+  }
+}

pkl-formatter/src/main/java/org/pkl/formatter/Generator.java

@@ -0,0 +1,160 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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 at
+ *
+ *     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 org.pkl.formatter;
+
+import java.util.HashSet;
+import java.util.Set;
+
+final class Generator {
+
+  static final int MAX = 100;
+  private static final String INDENT = "  ";
+
+  private final Appendable buf;
+  private int indent = 0;
+  private int size = 0;
+  private final Set<Integer> wrapped = new HashSet<>();
+  private boolean shouldAddIndent = false;
+
+  Generator(Appendable buf) {
+    this.buf = buf;
+  }
+
+  void generate(FormatNode node) {
+    node(node, Wrap.DETECT);
+  }
+
+  @SuppressWarnings("StatementWithEmptyBody")
+  private void node(FormatNode node, Wrap wrap) {
+    if (node instanceof Empty) {
+      // nothing
+    } else if (node instanceof Nodes n) {
+      for (var child : n.nodes()) {
+        node(child, wrap);
+      }
+    } else if (node instanceof Group g) {
+      var width = 0;
+      for (var child : g.nodes()) {
+        width += child.width(wrapped);
+      }
+      var groupWrap = wrap;
+      if (size + width > MAX) {
+        wrapped.add(g.id());
+        groupWrap = Wrap.ENABLED;
+      } else {
+        groupWrap = Wrap.DETECT;
+      }
+      for (var child : g.nodes()) {
+        node(child, groupWrap);
+      }
+    } else if (node instanceof IfWrap iw) {
+      if (wrapped.contains(iw.id())) {
+        node(iw.ifWrap(), Wrap.ENABLED);
+      } else {
+        node(iw.ifNotWrap(), wrap);
+      }
+    } else if (node instanceof Text t) {
+      text(t.text());
+    } else if (node instanceof Line) {
+      if (wrap.isEnabled()) {
+        newline(true);
+      }
+    } else if (node instanceof ForceLine) {
+      newline(true);
+    } else if (node instanceof SpaceOrLine) {
+      if (wrap.isEnabled()) {
+        newline(true);
+      } else {
+        text(" ");
+      }
+    } else if (node instanceof Space) {
+      text(" ");
+    } else if (node instanceof Indent ind) {
+      if (wrap.isEnabled() && !ind.nodes().isEmpty()) {
+        size += INDENT.length();
+        indent++;
+        for (var child : ind.nodes()) {
+          node(child, wrap);
+        }
+        indent--;
+      } else {
+        for (var child : ind.nodes()) {
+          node(child, wrap);
+        }
+      }
+    } else if (node instanceof MultilineStringGroup multi) {
+      var indentLength = indent * INDENT.length();
+      var oldIndent = indentFor(multi);
+      var previousNewline = false;
+      var nodes = multi.nodes();
+      for (var i = 0; i < nodes.size(); i++) {
+        var child = nodes.get(i);
+        if (child instanceof ForceLine) {
+          newline(false);
+        } else if (child instanceof Text t
+            && previousNewline
+            && t.text().isBlank()
+            && t.text().length() == oldIndent
+            && nodes.get(i + 1) instanceof ForceLine) {
+          // skip blank line indentation that will be repositioned
+        } else if (child instanceof Text t && previousNewline) {
+          text(reposition(t.text(), multi.endQuoteCol() - 1, indentLength));
+        } else {
+          node(child, Wrap.DETECT);
+        }
+        previousNewline = child instanceof ForceLine;
+      }
+    }
+  }
+
+  private void text(String value) {
+    try {
+      if (shouldAddIndent) {
+        for (var i = 0; i < indent; i++) {
+          buf.append(INDENT);
+        }
+        shouldAddIndent = false;
+      }
+      size += value.length();
+      buf.append(value);
+    } catch (java.io.IOException e) {
+      throw new java.io.UncheckedIOException(e);
+    }
+  }
+
+  private void newline(boolean shouldIndent) {
+    try {
+      size = INDENT.length() * indent;
+      buf.append('\n');
+      shouldAddIndent = shouldIndent;
+    } catch (java.io.IOException e) {
+      throw new java.io.UncheckedIOException(e);
+    }
+  }
+
+  // accept text indented by originalOffset characters (tabs or spaces)
+  // and return it indented by newOffset characters (spaces only)
+  private static String reposition(String text, int originalOffset, int newOffset) {
+    return " ".repeat(newOffset) + text.substring(originalOffset);
+  }
+
+  private static int indentFor(MultilineStringGroup multi) {
+    var nodes = multi.nodes();
+    if (nodes.size() < 2) return 0;
+    var beforeLast = nodes.get(nodes.size() - 2);
+    return beforeLast instanceof Text t ? t.text().length() : 0;
+  }
+}

pkl-formatter/src/main/java/org/pkl/formatter/GrammarVersion.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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 at
+ *
+ *     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 org.pkl.formatter;
+
+/** Grammar compatibility version. */
+public enum GrammarVersion {
+  V1(1, "0.25 - 0.29"),
+  V2(2, "0.30+");
+
+  private final int version;
+  private final String versionSpan;
+
+  GrammarVersion(int version, String versionSpan) {
+    this.version = version;
+    this.versionSpan = versionSpan;
+  }
+
+  public int getVersion() {
+    return version;
+  }
+
+  public String getVersionSpan() {
+    return versionSpan;
+  }
+
+  public static GrammarVersion latest() {
+    var latest = V1;
+    for (var v : values()) {
+      if (v.version > latest.version) {
+        latest = v;
+      }
+    }
+    return latest;
+  }
+}

pkl-formatter/src/main/java/org/pkl/formatter/NaturalOrderComparator.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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 at
+ *
+ *     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 org.pkl.formatter;
+
+import java.util.Comparator;
+
+final class NaturalOrderComparator implements Comparator<String> {
+
+  private final boolean ignoreCase;
+
+  NaturalOrderComparator(boolean ignoreCase) {
+    this.ignoreCase = ignoreCase;
+  }
+
+  NaturalOrderComparator() {
+    this(false);
+  }
+
+  @Override
+  public int compare(String s1, String s2) {
+    var i = 0;
+    var j = 0;
+
+    while (i < s1.length() && j < s2.length()) {
+      var c1 = ignoreCase ? Character.toLowerCase(s1.charAt(i)) : s1.charAt(i);
+      var c2 = ignoreCase ? Character.toLowerCase(s2.charAt(j)) : s2.charAt(j);
+
+      if (Character.isDigit(c1) && Character.isDigit(c2)) {
+        var pair1 = getNumber(s1, i);
+        var pair2 = getNumber(s2, j);
+
+        var numComparison = Long.compare(pair1.l, pair2.l);
+        if (numComparison != 0) {
+          return numComparison;
+        }
+        i = pair1.i;
+        j = pair2.i;
+      } else {
+        var charComparison = Character.compare(c1, c2);
+        if (charComparison != 0) {
+          return charComparison;
+        }
+        i++;
+        j++;
+      }
+    }
+
+    return Integer.compare(s1.length(), s2.length());
+  }
+
+  private static LongAndInt getNumber(String s, int startIndex) {
+    var i = startIndex;
+    while (i < s.length() && Character.isDigit(s.charAt(i))) {
+      i++;
+    }
+    try {
+      var number = Long.parseLong(s, startIndex, i, 10);
+      return new LongAndInt(number, i);
+    } catch (NumberFormatException e) {
+      return new LongAndInt(0L, i);
+    }
+  }
+
+  private record LongAndInt(long l, int i) {}
+}

pkl-formatter/src/main/java/org/pkl/formatter/Wrap.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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 at
+ *
+ *     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 org.pkl.formatter;
+
+enum Wrap {
+  ENABLED,
+  DETECT;
+
+  boolean isEnabled() {
+    return this == ENABLED;
+  }
+}

pkl-formatter/src/main/kotlin/org/pkl/formatter/Formatter.kt

@@ -1,103 +0,0 @@
-/*
- * Copyright © 2025-2026 Apple Inc. and the Pkl project authors. All rights reserved.
- *
- * 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 at
- *
- *     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 org.pkl.formatter
-
-import java.io.IOException
-import java.io.Reader
-import java.nio.file.Files
-import java.nio.file.Path
-import kotlin.jvm.Throws
-import org.pkl.formatter.ast.ForceLine
-import org.pkl.formatter.ast.Nodes
-import org.pkl.parser.GenericParser
-
-/**
- * A formatter for Pkl files that applies canonical formatting rules.
- *
- * @param grammarVersion grammar compatibility version
- */
-class Formatter
-@JvmOverloads
-constructor(private val grammarVersion: GrammarVersion = GrammarVersion.latest()) {
-
-  /**
-   * Formats a Pkl file from the given file path.
-   *
-   * @param path the path to the Pkl file to format
-   * @param grammarVersion grammar compatibility version
-   * @return the formatted Pkl source code as a string
-   * @throws java.io.IOException if the file cannot be read
-   */
-  @JvmOverloads
-  @Deprecated(message = "use format(path.readText()) instead")
-  fun format(path: Path, grammarVersion: GrammarVersion = GrammarVersion.latest()): String {
-    return Formatter(grammarVersion).format(Files.readString(path))
-  }
-
-  /**
-   * Formats the given Pkl source code text.
-   *
-   * @param text the Pkl source code to format
-   * @param grammarVersion grammar compatibility version
-   * @return the formatted Pkl source code as a string
-   */
-  @Deprecated(message = "use Formatter(grammarVersion).format(text) instead")
-  fun format(text: String, grammarVersion: GrammarVersion): String {
-    return Formatter(grammarVersion).format(text)
-  }
-
-  /**
-   * Formats the given Pkl source code text.
-   *
-   * @param text the Pkl source code to format
-   * @return the formatted Pkl source code as a string
-   */
-  fun format(text: String): String {
-    return buildString { format(text, this) }
-  }
-
-  /**
-   * Formats the given Pkl source code text.
-   *
-   * It is the caller's responsibility to close [input], and, if applicable, [output].
-   *
-   * @param input the Pkl source code to format
-   * @param output the formatted Pkl source code
-   * @throws java.io.IOException if an I/O error occurs during reading or writing
-   */
-  @Throws(IOException::class)
-  fun format(input: Reader, output: Appendable) {
-    format(input.readText(), output)
-  }
-
-  private fun format(input: String, output: Appendable) {
-    val ast = GenericParser().parseModule(input)
-    val formatAst = Builder(input, grammarVersion).format(ast)
-    // force a line at the end of the file
-    val nodes = Nodes(listOf(formatAst, ForceLine))
-    Generator(output).generate(nodes)
-  }
-}
-
-/** Grammar compatibility version. */
-enum class GrammarVersion(val version: Int, val versionSpan: String) {
-  V1(1, "0.25 - 0.29"),
-  V2(2, "0.30+");
-
-  companion object {
-    @JvmStatic fun latest(): GrammarVersion = entries.maxBy { it.version }
-  }
-}

pkl-formatter/src/main/kotlin/org/pkl/formatter/Generator.kt

@@ -1,145 +0,0 @@
-/*
- * Copyright © 2025-2026 Apple Inc. and the Pkl project authors. All rights reserved.
- *
- * 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 at
- *
- *     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 org.pkl.formatter
-
-import org.pkl.formatter.ast.Empty
-import org.pkl.formatter.ast.ForceLine
-import org.pkl.formatter.ast.FormatNode
-import org.pkl.formatter.ast.Group
-import org.pkl.formatter.ast.IfWrap
-import org.pkl.formatter.ast.Indent
-import org.pkl.formatter.ast.Line
-import org.pkl.formatter.ast.MultilineStringGroup
-import org.pkl.formatter.ast.Nodes
-import org.pkl.formatter.ast.Space
-import org.pkl.formatter.ast.SpaceOrLine
-import org.pkl.formatter.ast.Text
-import org.pkl.formatter.ast.Wrap
-
-internal class Generator(private val buf: Appendable) {
-  private var indent: Int = 0
-  private var size: Int = 0
-  private val wrapped: MutableSet<Int> = mutableSetOf()
-  private var shouldAddIndent = false
-
-  fun generate(node: FormatNode) {
-    node(node, Wrap.DETECT)
-  }
-
-  private fun node(node: FormatNode, wrap: Wrap) {
-    when (node) {
-      is Empty -> {}
-      is Nodes -> node.nodes.forEach { node(it, wrap) }
-      is Group -> {
-        val width = node.nodes.sumOf { it.width(wrapped) }
-        val wrap =
-          if (size + width > MAX) {
-            wrapped += node.id
-            Wrap.ENABLED
-          } else {
-            Wrap.DETECT
-          }
-        node.nodes.forEach { node(it, wrap) }
-      }
-      is IfWrap -> {
-        if (wrapped.contains(node.id)) {
-          node(node.ifWrap, Wrap.ENABLED)
-        } else {
-          node(node.ifNotWrap, wrap)
-        }
-      }
-      is Text -> text(node.text)
-      is Line -> {
-        if (wrap.isEnabled()) {
-          newline()
-        }
-      }
-      is ForceLine -> newline()
-      is SpaceOrLine -> {
-        if (wrap.isEnabled()) {
-          newline()
-        } else {
-          text(" ")
-        }
-      }
-      is Space -> text(" ")
-      is Indent -> {
-        if (wrap.isEnabled() && node.nodes.isNotEmpty()) {
-          size += INDENT.length
-          indent++
-          node.nodes.forEach { node(it, wrap) }
-          indent--
-        } else {
-          node.nodes.forEach { node(it, wrap) }
-        }
-      }
-      is MultilineStringGroup -> {
-        val indentLength = indent * INDENT.length
-        val oldIndent = indentFor(node)
-        var previousNewline = false
-        for ((i, child) in node.nodes.withIndex()) {
-          when {
-            child is ForceLine -> newline(shouldIndent = false) // don't indent
-            child is Text &&
-              previousNewline &&
-              child.text.isBlank() &&
-              child.text.length == oldIndent &&
-              node.nodes[i + 1] is ForceLine -> {}
-            child is Text && previousNewline ->
-              text(reposition(child.text, node.endQuoteCol - 1, indentLength))
-            else -> node(child, Wrap.DETECT) // always detect wrapping
-          }
-          previousNewline = child is ForceLine
-        }
-      }
-    }
-  }
-
-  private fun text(value: String) {
-    if (shouldAddIndent) {
-      repeat(times = indent) { buf.append(INDENT) }
-      shouldAddIndent = false
-    }
-    size += value.length
-    buf.append(value)
-  }
-
-  private fun newline(shouldIndent: Boolean = true) {
-    size = INDENT.length * indent
-    buf.append('\n')
-    shouldAddIndent = shouldIndent
-  }
-
-  // accept text indented by originalOffset characters (tabs or spaces)
-  // and return it indented by newOffset characters (spaces only)
-  private fun reposition(text: String, originalOffset: Int, newOffset: Int): String =
-    " ".repeat(newOffset) + text.drop(originalOffset)
-
-  // Returns the indent of this multiline string, which is the size of the last node before the
-  // closing quotes, or 0 if the closing quotes have no indentation
-  private fun indentFor(multi: MultilineStringGroup): Int {
-    val nodes = multi.nodes
-    if (nodes.size < 2) return 0
-    val beforeLast = nodes[nodes.lastIndex - 1]
-    return if (beforeLast is Text) beforeLast.text.length else 0
-  }
-
-  companion object {
-    // max line length
-    const val MAX = 100
-    private const val INDENT = "  "
-  }
-}

pkl-formatter/src/main/kotlin/org/pkl/formatter/NaturalOrderComparator.kt

@@ -1,66 +0,0 @@
-/*
- * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
- *
- * 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 at
- *
- *     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 org.pkl.formatter
-
-internal class NaturalOrderComparator(private val ignoreCase: Boolean = false) :
-  Comparator<String> {
-
-  override fun compare(s1: String, s2: String): Int {
-    var i = 0
-    var j = 0
-
-    while (i < s1.length && j < s2.length) {
-      val c1 = if (ignoreCase) s1[i].lowercaseChar() else s1[i]
-      val c2 = if (ignoreCase) s2[j].lowercaseChar() else s2[j]
-
-      if (c1.isDigit() && c2.isDigit()) {
-        val (num1, nextI) = getNumber(s1, i)
-        val (num2, nextJ) = getNumber(s2, j)
-
-        val numComparison = num1.compareTo(num2)
-        if (numComparison != 0) {
-          return numComparison
-        }
-        i = nextI
-        j = nextJ
-      } else {
-        val charComparison = c1.compareTo(c2)
-        if (charComparison != 0) {
-          return charComparison
-        }
-        i++
-        j++
-      }
-    }
-
-    return s1.length.compareTo(s2.length)
-  }
-
-  private fun getNumber(s: String, startIndex: Int): LongAndInt {
-    var i = startIndex
-    val start = i
-
-    while (i < s.length && s[i].isDigit()) {
-      i++
-    }
-    val numStr = s.substring(start, i)
-    val number = numStr.toLongOrNull() ?: 0L
-    return LongAndInt(number, i)
-  }
-
-  // use this instead of Pair to avoid boxing
-  private data class LongAndInt(val l: Long, var i: Int)
-}

pkl-formatter/src/main/kotlin/org/pkl/formatter/ast/FormatNode.kt

@@ -1,64 +0,0 @@
-/*
- * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
- *
- * 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 at
- *
- *     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 org.pkl.formatter.ast
-
-import org.pkl.formatter.Generator
-
-enum class Wrap {
-  ENABLED,
-  DETECT;
-
-  fun isEnabled(): Boolean = this == ENABLED
-}
-
-sealed interface FormatNode {
-  fun width(wrapped: Set<Int>): Int =
-    when (this) {
-      is Nodes -> nodes.sumOf { it.width(wrapped) }
-      is Group -> nodes.sumOf { it.width(wrapped) }
-      is Indent -> nodes.sumOf { it.width(wrapped) }
-      is IfWrap -> if (id in wrapped) ifWrap.width(wrapped) else ifNotWrap.width(wrapped)
-      is Text -> text.length
-      SpaceOrLine,
-      Space -> 1
-      ForceLine,
-      is MultilineStringGroup -> Generator.MAX
-      Empty -> 0
-      Line -> 0
-    }
-}
-
-data class Text(val text: String) : FormatNode
-
-object Empty : FormatNode
-
-object Line : FormatNode
-
-object ForceLine : FormatNode
-
-object SpaceOrLine : FormatNode
-
-object Space : FormatNode
-
-data class Indent(val nodes: List<FormatNode>) : FormatNode
-
-data class Nodes(val nodes: List<FormatNode>) : FormatNode
-
-data class Group(val id: Int, val nodes: List<FormatNode>) : FormatNode
-
-data class MultilineStringGroup(val endQuoteCol: Int, val nodes: List<FormatNode>) : FormatNode
-
-data class IfWrap(val id: Int, val ifWrap: FormatNode, val ifNotWrap: FormatNode) : FormatNode