Add pkl:syntax module

pkl-core/pkl-core.gradle.kts

@@ -59,6 +59,7 @@ dependencies {
   compileOnly(projects.pklExecutor)
 
   implementation(projects.pklParser)
+  implementation(projects.pklFormatter)
   implementation(libs.msgpack)
   implementation(libs.truffleApi)
   implementation(libs.graalSdk)

pkl-core/src/main/java/org/pkl/core/runtime/Identifier.java

@@ -172,6 +172,18 @@ public final class Identifier implements Comparable<Identifier> {
   // common in lambdas etc
   public static final Identifier IT = get("it");
 
+  // members of pkl.syntax#Node, pkl.syntax#Span and pkl.syntax#SourceLocation
+  public static final Identifier TYPE = get("type");
+  public static final Identifier CHILDREN = get("children");
+  public static final Identifier SPAN = get("span");
+  public static final Identifier START = get("start");
+  public static final Identifier END = get("end");
+  public static final Identifier LINE = get("line");
+  public static final Identifier COLUMN = get("column");
+
+  // members of pkl.syntax#Renderer
+  public static final Identifier GRAMMAR_VERSION = get("grammarVersion");
+
   private final String name;
 
   private Identifier(String name) {

pkl-core/src/main/java/org/pkl/core/runtime/ModuleCache.java

@@ -115,6 +115,8 @@ public synchronized VmTyped getOrLoad(
         case "settings":
           // always needed if ~/.pkl/settings.pkl is present
           return SettingsModule.getModule();
+        case "syntax":
+          return SyntaxModule.getModule();
         case "test":
           return TestModule.getModule();
         case "xml":