From 54d4be5411cbd1eed80ccefcdbf5a1868195d673 Mon Sep 17 00:00:00 2001 From: bensku Date: Sat, 13 Jul 2024 13:57:17 +0300 Subject: [PATCH] lua4jvm: Add table iteration support (WIP) pairs() is broken, possibly due to linker issues... Other things from this commit: * Intrinsic Java methods; used for optimizing pairs() loops * InternalLib - non-public functions that Lua code can indirectly access --- .../code4jvm/lua/ffi/JavaFunction.java | 14 ++- .../benjami/code4jvm/lua/ffi/LuaBinder.java | 4 +- .../code4jvm/lua/ffi/LuaIntrinsic.java | 13 +++ .../lua/ir/expr/FunctionCallExpr.java | 6 +- .../code4jvm/lua/ir/stmt/IteratorForStmt.java | 20 +++- .../code4jvm/lua/linker/CallSiteOptions.java | 13 ++- .../code4jvm/lua/linker/LuaLinker.java | 11 +- .../code4jvm/lua/runtime/LuaTable.java | 110 ++++++++++++++++++ .../benjami/code4jvm/lua/stdlib/BasicLib.java | 39 +++++++ .../code4jvm/lua/stdlib/InternalLib.java | 44 +++++++ .../code4jvm/lua/test/BasicLibTest.java | 12 ++ .../benjami/code4jvm/lua/test/LuaVmTest.java | 2 +- .../benjami/code4jvm/lua/test/TableTest.java | 42 +++++++ 13 files changed, 313 insertions(+), 17 deletions(-) create mode 100644 lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaIntrinsic.java create mode 100644 lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/InternalLib.java diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/JavaFunction.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/JavaFunction.java index fd5ee23..b28984b 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/JavaFunction.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/JavaFunction.java @@ -3,6 +3,7 @@ import java.lang.invoke.MethodHandle; import java.util.List; +import fi.benjami.code4jvm.lua.linker.CallSiteOptions; import fi.benjami.code4jvm.lua.ir.LuaType; /** @@ -62,16 +63,25 @@ public record Target( /** * Java method that should be called for this target. */ - MethodHandle method + MethodHandle method, + + /** + * Intrinsic id. If non-null, this target is ignored unless the + * {@link CallSiteOptions#intrinsicId call site} has same id set. + */ + String intrinsicId ) {} public record Arg(String name, LuaType type, boolean nullable) {} // TODO support functions for generating errors - public Target matchToArgs(LuaType[] argTypes) { + public Target matchToArgs(LuaType[] argTypes, String intrinsicId) { // Try all targets in order for (var target : targets) { + if (target.intrinsicId != null && !target.intrinsicId.equals(intrinsicId)) { + continue; // Intrinsic not allowed by caller + } if (checkArgs(target, argTypes) == MatchResult.SUCCESS) { return target; } diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaBinder.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaBinder.java index 2f92544..8fd5f01 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaBinder.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaBinder.java @@ -99,7 +99,9 @@ private JavaFunction.Target toFunctionTarget(Method method) { throw new IllegalStateException("lookup provided for LuaBinder has insufficient access", e); } - return new JavaFunction.Target(injectedArgs, args, method.isVarArgs(), LuaType.of(returnType), multipleReturns, handle); + var intrinsic = method.getAnnotation(LuaIntrinsic.class); + var intrinsicId = intrinsic != null ? intrinsic.value() : null; + return new JavaFunction.Target(injectedArgs, args, method.isVarArgs(), LuaType.of(returnType), multipleReturns, handle, intrinsicId); } private InjectedArg toInjectedArg(Class type, String source) { diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaIntrinsic.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaIntrinsic.java new file mode 100644 index 0000000..dd70fc3 --- /dev/null +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ffi/LuaIntrinsic.java @@ -0,0 +1,13 @@ +package fi.benjami.code4jvm.lua.ffi; + +import java.lang.annotation.ElementType; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; +import java.lang.annotation.Target; + +@Retention(RetentionPolicy.RUNTIME) +@Target(ElementType.METHOD) +public @interface LuaIntrinsic { + + String value(); +} diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/expr/FunctionCallExpr.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/expr/FunctionCallExpr.java index b162f5c..7542562 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/expr/FunctionCallExpr.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/expr/FunctionCallExpr.java @@ -23,6 +23,10 @@ private record CachedCall(LuaType[] argTypes, LuaType returnType) {} @Override public Value emit(LuaContext ctx, Block block) { + return emit(ctx, block, null); + } + + public Value emit(LuaContext ctx, Block block, String intrinsicId) { // Get expensive-to-compute types from cache var cache = (CachedCall) ctx.getCache(this); var argTypes = cache.argTypes(); @@ -31,7 +35,7 @@ public Value emit(LuaContext ctx, Block block) { // TODO constant bootstrap is broken due to upvalues var bootstrap = LuaLinker.BOOTSTRAP_DYNAMIC; var lastMultiVal = !args.isEmpty() && MultiVals.canReturnMultiVal(args.get(args.size() - 1)); - var options = new CallSiteOptions(ctx.owner(), argTypes, ctx.allowSpread(), lastMultiVal); + var options = new CallSiteOptions(ctx.owner(), argTypes, ctx.allowSpread(), lastMultiVal, intrinsicId); bootstrap = bootstrap.withCapturedArgs(ctx.addClassData(options)); // Evaluate arguments to values (function is first argument) diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/stmt/IteratorForStmt.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/stmt/IteratorForStmt.java index d975e4b..0f924bf 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/stmt/IteratorForStmt.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/ir/stmt/IteratorForStmt.java @@ -15,6 +15,7 @@ import fi.benjami.code4jvm.lua.ir.LuaBlock; import fi.benjami.code4jvm.lua.ir.LuaLocalVar; import fi.benjami.code4jvm.lua.ir.LuaType; +import fi.benjami.code4jvm.lua.ir.expr.FunctionCallExpr; import fi.benjami.code4jvm.lua.linker.CallSiteOptions; import fi.benjami.code4jvm.lua.linker.LuaLinker; import fi.benjami.code4jvm.lua.stdlib.LuaException; @@ -29,7 +30,7 @@ public record IteratorForStmt( List loopVars, List iterable ) implements IrNode { - + @Override public Value emit(LuaContext ctx, Block block) { // TODO code4jvm's LoopBlock is dangerously useless; return here if/when it is fixed @@ -47,9 +48,15 @@ public Value emit(LuaContext ctx, Block block) { // Before loop body, call the iterable to (hopefully) produce an array of: // iterator function, state, initial value for control variable, (TODO closing value) // TODO Java iterable interop? - ctx.setAllowSpread(true); - var iterator = iterable.get(0).emit(ctx, init); - ctx.setAllowSpread(false); + var first = iterable.get(0); + Value iterator; + if (first instanceof FunctionCallExpr call) { + ctx.setAllowSpread(true); + iterator = call.emit(ctx, block, "iteratorFor"); + ctx.setAllowSpread(false); + } else { + iterator = first.emit(ctx, block); + } // We might've gotten a multival of next, state, control or only some of those // Set state, control to null as they are technically optional @@ -68,6 +75,7 @@ public Value emit(LuaContext ctx, Block block) { inner.add(next, ArrayAccess.get(array, Constant.of(0))); // This must exist, but TODO improve error messages inner.add(Jump.to(init, Jump.Target.END, Condition.equal(length, Constant.of(1)))); inner.add(ArrayAccess.get(array, Constant.of(1))); + inner.add(Jump.to(init, Jump.Target.END, Condition.equal(length, Constant.of(2)))); inner.add(control, ArrayAccess.get(array, Constant.of(2))); }); innerInit.fallback(inner -> { @@ -96,9 +104,9 @@ public Value emit(LuaContext ctx, Block block) { } block.add(init); - // In loop body, call next(state, control) - // (types are unknown because we can't yet track them for multivals) + // In loop body, call next(state, control) var bootstrap = LuaLinker.BOOTSTRAP_DYNAMIC; + // Types are unknown because we can't yet track them for multivals var options = new CallSiteOptions(ctx.owner(), new LuaType[] {LuaType.UNKNOWN, LuaType.UNKNOWN}, true, false); bootstrap = bootstrap.withCapturedArgs(ctx.addClassData(options)); var target = CallTarget.dynamic(bootstrap, Type.OBJECT, "_", Type.OBJECT, Type.OBJECT); diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/CallSiteOptions.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/CallSiteOptions.java index b397d5c..acda176 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/CallSiteOptions.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/CallSiteOptions.java @@ -29,9 +29,20 @@ public record CallSiteOptions( * as the its last argument. This forces the linker to inspect the * arguments and (attempt to) spread it over arguments. */ - boolean spreadArguments + boolean spreadArguments, + + /** + * Intrinsic id of this call site. If non-null, when the call target is + * a Java function, its targets with same intrinsic id are selected in + * addition to + */ + String intrinsicId ) { + public CallSiteOptions(LuaVm owner, LuaType[] types, boolean spreadResults, boolean spreadArguments) { + this(owner, types, spreadResults, spreadArguments, null); + } + /** * Creates call site options for a non-function call. * @param types Types at call site. Use UNKNOWNs if not known or needed. diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/LuaLinker.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/LuaLinker.java index e153041..aa0d0fc 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/LuaLinker.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/linker/LuaLinker.java @@ -35,7 +35,7 @@ public class LuaLinker { private static final MethodHandles.Lookup LOOKUP = MethodHandles.lookup(); public static final Type TYPE = Type.of(LuaLinker.class); - static final MethodHandle TARGET_HAS_CHANGED, PROTOTYPE_HAS_CHANGED, TYPE_HAS_CHANGED, + public static final MethodHandle TARGET_HAS_CHANGED, PROTOTYPE_HAS_CHANGED, TYPE_HAS_CHANGED, ARRAY_FIRST, SHAPE_ARRAYS, UPDATE_SITE, NEW_WRAPPER_EX, WRAPPER_EX_CAUSE; private static final class WrapperException extends RuntimeException { @@ -126,6 +126,7 @@ public static LuaCallTarget linkCall(LuaCallSite meta, Object callable, Object.. } } else if (callable instanceof JavaFunction function) { // Java method exposed to Lua via FFI + var intrinsicId = meta.options.intrinsicId(); var specializedTypes = compiledTypes; JavaFunction.Target funcTarget; if (meta.hasUnknownTypes) { @@ -134,16 +135,16 @@ public static LuaCallTarget linkCall(LuaCallSite meta, Object callable, Object.. // Use them! Runtime types are never LESS applicable than compile-time types // so we don't need to check anything else specializedTypes = Arrays.stream(args).map(LuaType::of).toArray(LuaType[]::new); - funcTarget = function.matchToArgs(specializedTypes); + funcTarget = function.matchToArgs(specializedTypes, intrinsicId); meta.usesRuntimeTypes = true; } else { // Too many type changes; we'd prefer to use compile-time types - funcTarget = function.matchToArgs(compiledTypes); + funcTarget = function.matchToArgs(compiledTypes, intrinsicId); if (funcTarget == null) { // But it is entirely possible that we can't! // Performance be damned, a call that has correct types at runtime must not fail specializedTypes = Arrays.stream(args).map(LuaType::of).toArray(LuaType[]::new); - funcTarget = function.matchToArgs(specializedTypes); + funcTarget = function.matchToArgs(specializedTypes, intrinsicId); meta.usesRuntimeTypes = true; } else { meta.usesRuntimeTypes = false; @@ -151,7 +152,7 @@ public static LuaCallTarget linkCall(LuaCallSite meta, Object callable, Object.. } } else { // All argument types are known compile-time - funcTarget = function.matchToArgs(compiledTypes); + funcTarget = function.matchToArgs(compiledTypes, intrinsicId); meta.usesRuntimeTypes = false; } diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/runtime/LuaTable.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/runtime/LuaTable.java index 22799c2..88d3894 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/runtime/LuaTable.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/runtime/LuaTable.java @@ -304,4 +304,114 @@ public int arraySize() { public Object shape() { return shape; } + + /** + * Gets the next entry in this table. + * + *

This method supports stateless iteration, much like Lua's next() + * function. When writing Java, this is probably not what you want! + * Stateful iterators produced by {@link #iterator()} are more efficient, + * potentially significantly so. + * @param prevKey Key of the previous entry, or null to start from scratch. + * @return A pair of key and value. + */ + public Object[] next(Object prevKey) { + if (prevKey == null) { + if (arraySize != 0) { + // First call, array has at least one member + return new Object[] {1d, getArray(1)}; + } else { + // First call, no array members -> return "first" table member + for (var i = arrayCapacity; i < table.length; i++) { + if (table[i] != null) { + return new Object[] {keys[i - arrayCapacity], table[i]}; + } + } + } + } + + if (prevKey instanceof Double index && index < arraySize + 1) { + // Iterate the array in order as long as we have elements + var newIndex = index + 1; + return new Object[] {newIndex, getArray((int) newIndex)}; + } + + // Out of array members + for (var i = getSlot(prevKey) + 1; i < table.length; i++) { + if (table[i] != null) { + return new Object[] {keys[i - arrayCapacity], table[i]}; + } + } + return null; // Table end + } + + /** + * Creates a stateful table iterator of this table. + * + *

Note: Table iterators are not compatible with + * {@link java.util.Iterator}! + * @return A table iterator. + */ + public Iterator iterator() { + return new Iterator(); + } + + /** + * A stateful table iterator. + * + *

Typical usage: + * 

+	 * var it = table.iterator();
+	 * while (it.next()) {
+	 *     var key = it.key();
+	 *     var value = it.value();
+	 * }
+	 *
+ * + */ + public class Iterator { + + private boolean array; + private int index; + + private Iterator() { + this.array = false; + this.index = 0; + } + + public boolean next() { + return array ? nextArray() : nextTable(); + } + + private boolean nextArray() { + index++; + if (index >= arraySize) { + // Reached array end + array = false; + index = arrayCapacity - 1; // Jump over possible unused array space + return nextTable(); // Table might or might not have entries + } + return true; + } + + private boolean nextTable() { + // Iterate over empty space until we find next entry + for (var i = index + 1; i < table.length; i++) { + if (table[i] != null) { + index = i; + return true; + } + } + index = table.length; + return false; + } + + public Object key() { + return array ? (double) index : keys[index]; + } + + public Object value() { + return table[index]; + } + } } diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/BasicLib.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/BasicLib.java index b201edf..c864ef5 100644 --- a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/BasicLib.java +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/BasicLib.java @@ -12,10 +12,14 @@ import fi.benjami.code4jvm.lua.ffi.LuaLibrary; import fi.benjami.code4jvm.lua.ffi.Nullable; import fi.benjami.code4jvm.lua.ir.LuaType; +import fi.benjami.code4jvm.lua.linker.CallSiteOptions; +import fi.benjami.code4jvm.lua.linker.LuaCallSite; +import fi.benjami.code4jvm.lua.linker.LuaLinker; import fi.benjami.code4jvm.lua.ffi.Inject; import fi.benjami.code4jvm.lua.ffi.JavaFunction; import fi.benjami.code4jvm.lua.ffi.LuaBinder; import fi.benjami.code4jvm.lua.ffi.LuaExport; +import fi.benjami.code4jvm.lua.ffi.LuaIntrinsic; import fi.benjami.code4jvm.lua.runtime.LuaFunction; import fi.benjami.code4jvm.lua.runtime.LuaTable; @@ -189,4 +193,39 @@ public static String type(Object value) { return LuaType.of(value).name(); } + private static final JavaFunction INTRINSIC_ITERATOR = InternalLib.FUNCTIONS.get("intrinsicIterator"), + TABLE_ITERATOR = InternalLib.FUNCTIONS.get("tableIterator"); + + @LuaExport("pairs") + @LuaIntrinsic("iteratorFor") + private static Object[] pairsStateful(@Inject LuaVm vm, Object iterable) throws Throwable { + if (iterable instanceof LuaTable table + && (table.metatable() == null || table.metatable().get("__pairs") == null)) { + // Normal Lua table; let's cheat a bit and use a stateful table iterator (intrinsic path) + return new Object[] {INTRINSIC_ITERATOR, table.iterator()}; + } + + // Aside of the above fast path, delegate to normal pairs + return pairs(vm, iterable); + } + + @LuaExport("pairs") + private static Object[] pairs(@Inject LuaVm vm, Object iterable) throws Throwable { + if (iterable instanceof LuaTable table) { + if (table.metatable() != null) { + var metamethod = table.metatable().get("__pairs"); + if (metamethod != null) { + // Call __pairs and use whatever it returns as an iterator + var target = LuaLinker.linkCall(new LuaCallSite(null, CallSiteOptions.nonFunction(vm, LuaType.TABLE)), + metamethod, table); + return (Object[]) target.target().invoke(metamethod, table); + } + } + // No __pairs, just iterate over the table normally (non-intrinsic path) + return new Object[] {TABLE_ITERATOR, table}; + } else { + throw new LuaException("value not iterable"); + } + } + } diff --git a/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/InternalLib.java b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/InternalLib.java new file mode 100644 index 0000000..14d1dbe --- /dev/null +++ b/lua4jvm/src/main/java/fi/benjami/code4jvm/lua/stdlib/InternalLib.java @@ -0,0 +1,44 @@ +package fi.benjami.code4jvm.lua.stdlib; + +import java.lang.invoke.MethodHandles; +import java.util.Collections; +import java.util.HashMap; +import java.util.Map; + +import fi.benjami.code4jvm.lua.ffi.JavaFunction; +import fi.benjami.code4jvm.lua.ffi.LuaBinder; +import fi.benjami.code4jvm.lua.ffi.LuaExport; +import fi.benjami.code4jvm.lua.runtime.LuaTable; + +class InternalLib { + + public static final Map FUNCTIONS; + + static { + var functions = new LuaBinder(MethodHandles.lookup()).bindFunctionsFrom(InternalLib.class); + var map = new HashMap(); + for (var func : functions) { + map.put(func.name(), func); + } + FUNCTIONS = Collections.unmodifiableMap(map); + } + + private static final Object[] PAIRS_ARRAY = new Object[2]; + + @LuaExport("intrinsicIterator") + private static Object[] intrinsicIterator(LuaTable.Iterator iterator) { + if (iterator.next()) { + PAIRS_ARRAY[0] = iterator.key(); + PAIRS_ARRAY[1] = iterator.value(); + } else { + PAIRS_ARRAY[0] = null; // Signal loop end + PAIRS_ARRAY[1] = null; // ... and allow last value to be GC'd later + } + return PAIRS_ARRAY; + } + + @LuaExport("tableIterator") + private static Object[] tableIterator(LuaTable table, String prevKey) { + return table.next(prevKey); + } +} diff --git a/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/BasicLibTest.java b/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/BasicLibTest.java index f28f65d..dddd643 100644 --- a/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/BasicLibTest.java +++ b/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/BasicLibTest.java @@ -10,6 +10,7 @@ import java.nio.file.Files; import java.nio.file.Path; +import org.junit.jupiter.api.Disabled; import org.junit.jupiter.api.Test; import fi.benjami.code4jvm.lua.LuaVm; @@ -109,4 +110,15 @@ public void dofile() throws Throwable { trustedVm.execute("dofile(\"src/test/resources/dofile.lua\")"); assertTrue((boolean) trustedVm.globals().get("DOFILE_SUCCESS")); } + + @Test + @Disabled + public void pairs() throws Throwable { + vm.execute(""" + tbl = {foo = 1, bar = 2, baz = 3} + for k,v in pairs(tbl) do + + end + """); + } } diff --git a/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/LuaVmTest.java b/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/LuaVmTest.java index 6e07fac..405c797 100644 --- a/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/LuaVmTest.java +++ b/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/LuaVmTest.java @@ -214,7 +214,7 @@ public void callJavaFunction() throws Throwable { var handle = MethodHandles.lookup().findVirtual(Function.class, "apply", MethodType.methodType(Object.class, Object.class)).bindTo(javaFunc); var callable = new JavaFunction("javaFunc", List.of( - new JavaFunction.Target(List.of(), List.of(new JavaFunction.Arg("str", LuaType.STRING, false)), false, LuaType.STRING, false, handle) + new JavaFunction.Target(List.of(), List.of(new JavaFunction.Arg("str", LuaType.STRING, false)), false, LuaType.STRING, false, handle, null) ), null); var func = (LuaFunction) vm.execute(""" return function (f, arg) diff --git a/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/TableTest.java b/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/TableTest.java index a6389d8..349cb85 100644 --- a/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/TableTest.java +++ b/lua4jvm/src/test/java/fi/benjami/code4jvm/lua/test/TableTest.java @@ -4,6 +4,9 @@ import static org.junit.jupiter.api.Assertions.assertInstanceOf; import static org.junit.jupiter.api.Assertions.assertNull; +import java.util.HashSet; +import java.util.Set; + import org.junit.jupiter.api.BeforeEach; import org.junit.jupiter.api.Test; @@ -232,4 +235,43 @@ public void mutableMetatable() throws Throwable { meta.set("__index", null); assertNull(func.call(table)); } + + @Test + public void tableIterators() { + var table = new LuaTable(); + table.set("foo", 1d); + table.set("bar", 2d); + table.set("baz", 3d); + + var itKeys = new HashSet<>(); + var itVals = new HashSet<>(); + var nextKeys = new HashSet<>(); + var nextVals = new HashSet<>(); + + var it = table.iterator(); + while (it.next()) { + itKeys.add(it.key()); + itVals.add(it.value()); + } + + Object prevKey = null; + do { + var entry = table.next(prevKey); + if (entry != null) { + prevKey = entry[0]; + nextKeys.add(entry[0]); + nextVals.add(entry[1]); + } else { + prevKey = null; + } + } while (prevKey != null); + + var keys = Set.of("foo", "bar", "baz"); + var values = Set.of(1d, 2d, 3d); + + assertEquals(keys, itKeys); + assertEquals(values, itVals); + assertEquals(keys, nextKeys); + assertEquals(values, nextVals); + } }