import org.cojen.classfile.TypeDesc;
import org.simantics.scl.compiler.common.datatypes.Constructor;
+import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
import org.simantics.scl.compiler.common.names.Name;
import org.simantics.scl.compiler.constants.Constant;
import org.simantics.scl.compiler.constants.JavaTypeInstanceConstructor;
import org.simantics.scl.compiler.elaboration.expressions.EIntegerLiteral;
import org.simantics.scl.compiler.elaboration.expressions.EListLiteral;
import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
+import org.simantics.scl.compiler.elaboration.expressions.EPreCHRRulesetConstructor;
import org.simantics.scl.compiler.elaboration.expressions.EVar;
import org.simantics.scl.compiler.elaboration.expressions.Expression;
import org.simantics.scl.compiler.elaboration.expressions.Variable;
import org.simantics.scl.compiler.elaboration.java.JavaMethodDeclaration;
import org.simantics.scl.compiler.elaboration.macros.StandardMacroRule;
import org.simantics.scl.compiler.elaboration.modules.DeprecatedProperty;
+ import org.simantics.scl.compiler.elaboration.modules.DerivedProperty;
import org.simantics.scl.compiler.elaboration.modules.InlineProperty;
import org.simantics.scl.compiler.elaboration.modules.MethodImplementation;
import org.simantics.scl.compiler.elaboration.modules.PrivateProperty;
import org.simantics.scl.compiler.elaboration.modules.TypeClass;
import org.simantics.scl.compiler.elaboration.modules.TypeClassInstance;
import org.simantics.scl.compiler.elaboration.modules.TypeClassMethod;
+import org.simantics.scl.compiler.elaboration.modules.TypeDescriptor;
import org.simantics.scl.compiler.elaboration.query.Query;
import org.simantics.scl.compiler.elaboration.query.pre.QPreGuard;
import org.simantics.scl.compiler.elaboration.relations.ConcreteRelation;
import org.simantics.scl.compiler.internal.parsing.declarations.DMappingRelationAst;
import org.simantics.scl.compiler.internal.parsing.declarations.DRelationAst;
import org.simantics.scl.compiler.internal.parsing.declarations.DRuleAst;
+import org.simantics.scl.compiler.internal.parsing.declarations.DRulesetAst;
import org.simantics.scl.compiler.internal.parsing.declarations.DTypeAst;
import org.simantics.scl.compiler.internal.parsing.declarations.DValueAst;
import org.simantics.scl.compiler.internal.parsing.declarations.DValueTypeAst;
public void addTypesToEnvironment(
ArrayList<DDataAst> dataTypesAst,
ArrayList<DTypeAst> typeAliasesAst,
- ArrayList<DEffectAst> effectsAst) {
+ ArrayList<DEffectAst> effectsAst,
+ ArrayList<DRulesetAst> rulesetsAst) {
for(DDataAst dataType : dataTypesAst) {
dataType.parameterKinds = new Kind[dataType.parameters.length];
Kind constructorKind = Kinds.STAR;
NameExistenceChecks.checkIfTypeExists(errorLog,
dataType.location, importedEnvironment, dataType.name);
- if(module.addTypeDescriptor(dataType.name, typeConstructor))
- errorLog.log(dataType.location, "Type "+dataType.name+" has already been defined in this module.");
+ addTypeDescriptor(dataType.location, dataType.name, typeConstructor);
dataType.typeConstructor = typeConstructor;
}
TypeAlias alias = new TypeAlias(Types.con(moduleName, typeAlias.name), typeAlias.parameters.length);
NameExistenceChecks.checkIfTypeExists(errorLog,
typeAlias.location, importedEnvironment, typeAlias.name);
- if(module.addTypeDescriptor(typeAlias.name, alias)) {
- errorLog.log(typeAlias.location, "Type alias "+typeAlias.name+" has already been defined in this module.");
- }
+ addTypeDescriptor(typeAlias.location, typeAlias.name, alias);
}
for(DEffectAst effect : effectsAst) {
TypeDesc.forClass(effect.threadLocalType)
));
if(module.addEffectConstructor(effect.name, effectConstructor))
- errorLog.log(effect.location, "Type "+effect.name+" has already been defined in this module.");
- }
+ errorLog.log(effect.location, "Effect "+effect.name+" has already been defined in this module.");
+ }
+ for(DRulesetAst ruleset : rulesetsAst) {
+ ruleset.type = Types.con(moduleName, ruleset.name);
+ ruleset.className = compilationContext.namingPolicy.getDataTypeClassName(ruleset.name);
+ StandardTypeConstructor typeConstructor = new StandardTypeConstructor(ruleset.type, Kinds.STAR,
+ TypeDesc.forClass(ruleset.className), ruleset.documentation == null ? null : ruleset.documentation.documentation);
+ typeConstructor.external = true;
+ addTypeDescriptor(ruleset.location, ruleset.name, typeConstructor);
+ }
javaTypeTranslator = new JavaTypeTranslator(compilationContext.environment);
compilationContext.javaTypeTranslator = javaTypeTranslator;
}
+
+ private void addTypeDescriptor(long location, String name, TypeDescriptor typeDescriptor) {
+ if(module.addTypeDescriptor(name, typeDescriptor))
+ errorLog.log(location, "Type "+name+" has already been defined in this module.");
+ }
private static final int[] EMPTY_INT_ARRAY = new int[0];
String fullName = instancePrefix + valueName;
long loc = valueDefs.getDefinition(valueName).get(0).location;
valueDefinitionsAst.addFrom(valueDefs, valueName, fullName);
+ valueDefinitionsAst.setDerived(fullName);
/*valueDefinitionsAst.addAnnotation(fullName, new DAnnotationAst(new EVar("@private"),
Collections.<Expression>emptyList()));*/
TypeClassMethod method = typeClass.methods.get(valueName);
}
}
+ public void processRulesets(ArrayList<DRulesetAst> rulesetsAst) {
+ for(DRulesetAst ruleset : rulesetsAst) {
+ String constructorName = "create" + ruleset.name;
+ supplementedTypeAnnotations.add(new SupplementedValueType(ruleset.location, constructorName, Types.functionE(Types.PUNIT, Types.PROC, ruleset.type)));
+ try {
+ valueDefinitionsAst.add(new DValueAst(new EVar(constructorName), new EPreCHRRulesetConstructor(ruleset)));
+ } catch (NotPatternException e) {
+ throw new InternalCompilerError(ruleset.location, e);
+ }
+ }
+ }
+
/**
* Convert a java class method into a {@link CallJava} instance.
* Compilation errors are logged for failures in finding the named class or in accessing the method.
value.definitionLocation = location;
if(module.addValue(value))
errorLog.log(location, "Value " + name + " is already defined.");
+ if(valueDefinitionsAst.isDerived(name))
+ value.addProperty(DerivedProperty.INSTANCE);
}
for(DValueTypeAst valueTypeAst : typeAnnotationsAst)
for(EVar name : valueTypeAst.names) {
import org.simantics.scl.compiler.constants.BooleanConstant;
import org.simantics.scl.compiler.constants.Constant;
import org.simantics.scl.compiler.constants.IntegerConstant;
+import org.simantics.scl.compiler.constants.JavaConstructor;
import org.simantics.scl.compiler.constants.JavaMethod;
+import org.simantics.scl.compiler.constants.NoRepConstant;
import org.simantics.scl.compiler.constants.generic.CallJava;
import org.simantics.scl.compiler.constants.generic.MethodRef.FieldRef;
import org.simantics.scl.compiler.constants.generic.MethodRef.SetFieldRef;
+import org.simantics.scl.compiler.elaboration.chr.analysis.CHRConstraintGGInfo;
import org.simantics.scl.compiler.elaboration.chr.analysis.UsageAnalysis;
+import org.simantics.scl.compiler.elaboration.chr.plan.CHRSearchPlan;
import org.simantics.scl.compiler.elaboration.chr.plan.PlanRealizer;
-import org.simantics.scl.compiler.elaboration.chr.plan.PrioritizedPlan;
import org.simantics.scl.compiler.elaboration.chr.relations.CHRConstraint;
import org.simantics.scl.compiler.elaboration.contexts.SimplificationContext;
import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
import org.simantics.scl.compiler.elaboration.expressions.Variable;
import org.simantics.scl.compiler.elaboration.expressions.VariableProcedure;
+import org.simantics.scl.compiler.elaboration.expressions.block.IncludeStatement;
+import org.simantics.scl.compiler.environment.AmbiguousNameException;
import org.simantics.scl.compiler.errors.Locations;
-import org.simantics.scl.compiler.internal.codegen.chr.CHRCodeGenerator;
+import org.simantics.scl.compiler.internal.codegen.chr.CHRCodeGenerationConstants;
+import org.simantics.scl.compiler.internal.codegen.chr.CHRRuntimeRulesetCodeGenerator;
import org.simantics.scl.compiler.internal.codegen.references.BoundVar;
import org.simantics.scl.compiler.internal.codegen.references.IVal;
+import org.simantics.scl.compiler.internal.codegen.ssa.SSAFunction;
import org.simantics.scl.compiler.internal.codegen.types.StandardTypeConstructor;
import org.simantics.scl.compiler.internal.codegen.writer.CodeWriter;
import org.simantics.scl.compiler.internal.parsing.Symbol;
import org.simantics.scl.compiler.types.TVar;
import org.simantics.scl.compiler.types.Type;
import org.simantics.scl.compiler.types.Types;
+import org.simantics.scl.runtime.chr.CHRContext;
+import gnu.trove.map.hash.THashMap;
import gnu.trove.map.hash.TObjectIntHashMap;
import gnu.trove.set.hash.THashSet;
import gnu.trove.set.hash.TIntHashSet;
public ArrayList<CHRConstraint> constraints = new ArrayList<CHRConstraint>();
public ArrayList<CHRRule> rules = new ArrayList<CHRRule>();
+ public ArrayList<IncludeStatement> includes = new ArrayList<IncludeStatement>();
+ public THashMap<CHRConstraint, IncludeStatement> constraintSourceMap = new THashMap<CHRConstraint, IncludeStatement>();
+ public THashMap<CHRConstraint, CHRConstraintGGInfo> activeConstraintGGInfo = new THashMap<CHRConstraint, CHRConstraintGGInfo>(); // contains also imported constraints
+ public THashMap<IncludeStatement, ArrayList<CHRConstraint>> inverseActiveConstraintSourceMap = new THashMap<IncludeStatement, ArrayList<CHRConstraint>>();
+
+ public boolean extensible;
public CHRConstraint initConstraint;
public int priorityCount;
- public String storeClassName;
- public TCon storeType;
- public BoundVar storeVariable;
- public TypeDesc storeTypeDesc;
- public Constant activateProcedure;
+ public int initialPriorityNumber = 0;
+
+ public String runtimeRulesetClassName;
+ public TCon runtimeRulesetType;
+ public BoundVar runtimeRulesetVariable;
+ public TypeDesc runtimeRulesetTypeDesc;
public Constant readCurrentId;
public Constant writeCurrentId;
private CompilationContext cachedContext;
// For code generation
- public BoundVar this_;
- public BoundVar[] parameters;
- public TypeDesc[] parameterTypeDescs;
+ public CHRRulesetObject rulesetObject;
+ public SSAFunction initializer;
+ public SSAFunction deinitializer;
public CHRRuleset() {
initConstraint = new CHRConstraint(Locations.NO_LOCATION, INIT_CONSTRAINT, Type.EMPTY_ARRAY);
}
public void resolve(TranslationContext context) {
+ boolean failedIncludes = false;
+ for(IncludeStatement include : includes) {
+ try {
+ include.ruleset = context.resolveRuleset(include.name.text);
+ if(include.ruleset == null) {
+ failedIncludes = true;
+ context.getErrorLog().log(include.name.location, "Couldn't resolve ruleset " + include.name + ".");
+ continue;
+ }
+ include.value = include.value.resolve(context);
+ for(CHRConstraint constraint : include.ruleset.constraints) {
+ context.newCHRConstraint(constraint.name, constraint);
+ constraintSourceMap.put(constraint, include);
+ }
+ } catch (AmbiguousNameException e) {
+ failedIncludes = true;
+ context.getErrorLog().log(include.name.location, e.getMessage());
+ }
+ }
+ if(failedIncludes)
+ return;
for(CHRConstraint constraint : constraints)
context.newCHRConstraint(constraint.name, constraint);
priorityCount = 0;
}
public void collectRefs(TObjectIntHashMap<Object> allRefs, TIntHashSet refs) {
+ for(IncludeStatement include : includes)
+ include.value.collectRefs(allRefs, refs);
for(CHRRule rule : rules)
rule.collectRefs(allRefs, refs);
}
public void checkType(TypingContext context) {
+ for(IncludeStatement include : includes)
+ include.value = include.value.checkType(context, include.ruleset.runtimeRulesetType);
for(CHRRule rule : rules)
rule.checkType(context);
}
public void collectVars(TObjectIntHashMap<Variable> allVars, TIntHashSet vars) {
+ for(IncludeStatement include : includes)
+ include.value.collectVars(allVars, vars);
for(CHRRule rule : rules)
rule.collectVars(allVars, vars);
}
public void forVariables(VariableProcedure procedure) {
+ for(IncludeStatement include : includes)
+ include.value.forVariables(procedure);
for(CHRRule rule : rules)
rule.forVariables(procedure);
}
public void collectFreeVariables(THashSet<Variable> vars) {
+ for(IncludeStatement include : includes)
+ include.value.collectFreeVariables(vars);
for(CHRRule rule : rules)
rule.collectFreeVariables(vars);
}
rule.setLocationDeep(loc);
}
}
+
+ public int getMinimumPriority(CHRConstraint constraint) {
+ CHRConstraintGGInfo info = activeConstraintGGInfo.get(constraint);
+ if(info == null)
+ return Integer.MAX_VALUE;
+ else
+ return info.minimumPriority;
+ }
+
+ public int getAndUpdateNextPriority(CHRConstraint constraint, int nextPriority) {
+ CHRConstraintGGInfo info = activeConstraintGGInfo.get(constraint);
+ if(info == null)
+ return Integer.MAX_VALUE;
+ else {
+ int result = info.nextPriority;
+ info.nextPriority = nextPriority;
+ return result;
+ }
+ }
public void compile(SimplificationContext context) {
initializeCodeGeneration(context.getCompilationContext());
+ if(extensible)
+ applyExtensibleDefaults();
UsageAnalysis.analyzeUsage(this);
- for(CHRRule rule : rules)
+ for(CHRRule rule : rules) {
rule.compile(context.getCompilationContext(), initConstraint);
+ for(CHRSearchPlan plan : rule.plans) {
+ CHRConstraint constraint = plan.constraint;
+ if(!activeConstraintGGInfo.containsKey(constraint)) {
+ activeConstraintGGInfo.put(constraint, new CHRConstraintGGInfo(rule.priority));
+ IncludeStatement include = constraintSourceMap.get(constraint);
+ if(include != null) {
+ ArrayList<CHRConstraint> list = inverseActiveConstraintSourceMap.get(include);
+ if(list == null) {
+ list = new ArrayList<CHRConstraint>(4);
+ inverseActiveConstraintSourceMap.put(include, list);
+ }
+ list.add(constraint);
+ }
+ }
+ }
+ }
// remove init constraint if it is not useful
- if(initConstraint.plans.isEmpty()) {
+ if(getMinimumPriority(initConstraint) == Integer.MAX_VALUE) {
constraints.remove(0);
initConstraint = null;
}
+ }
+
+ private void applyExtensibleDefaults() {
for(CHRConstraint constraint : constraints) {
- constraint.plans.sort((PrioritizedPlan a, PrioritizedPlan b) -> {
- return Integer.compare(a.priority, b.priority);
- });
- /*System.out.println(constraint.name);
- for(PrioritizedPlan plan : constraint.plans) {
- System.out.println(" priority " + plan.priority);
- for(PlanOp op : plan.ops)
- System.out.println(" " + op);
- }*/
+ // FIXME Too much indexing!!!
+ int max = 1 << constraint.parameterTypes.length;
+ for(int i=0;i<max;++i)
+ constraint.getOrCreateIndex(cachedContext, i);
++ constraint.setMayBeRemoved();
+ /*
+ constraint.getOrCreateIndex(cachedContext, 0);
+ if(constraint.parameterTypes.length > 0)
+ constraint.getOrCreateIndex(cachedContext, 1);*/
}
}
public void simplify(SimplificationContext context) {
+ for(IncludeStatement include : includes)
+ include.value = include.value.simplify(context);
for(CHRRule rule : rules)
rule.simplify(context);
}
+ public void setRulesetType(TCon type, String className) {
+ this.runtimeRulesetType = type;
+ this.runtimeRulesetClassName = className;
+ }
+
public void initializeCodeGeneration(CompilationContext context) {
cachedContext = context; // FIXME remove
- String suffix = context.namingPolicy.getFreshClosureClassNameSuffix();
- storeType = Types.con(context.namingPolicy.getModuleName(), "CHR" + suffix);
- storeClassName = context.namingPolicy.getModuleClassName() + suffix;
- storeTypeDesc = TypeDesc.forClass(storeClassName);
- storeVariable = new BoundVar(storeType);
+ boolean createTypeDesc = false;
+ if(runtimeRulesetType == null) {
+ String suffix = context.namingPolicy.getFreshClosureClassNameSuffix();
+ setRulesetType(Types.con(context.namingPolicy.getModuleName(), "CHR" + suffix), context.namingPolicy.getModuleClassName() + suffix);
+ createTypeDesc = true;
+ }
+ runtimeRulesetTypeDesc = TypeDesc.forClass(runtimeRulesetClassName);
+ runtimeRulesetVariable = new BoundVar(runtimeRulesetType);
for(CHRConstraint constraint : constraints)
constraint.initializeCodeGeneration(context, this);
- activateProcedure = new JavaMethod(true, storeClassName, "activate", Types.PROC, Types.UNIT, storeType, Types.INTEGER);
- readCurrentId = new CallJava(TVar.EMPTY_ARRAY, Types.PROC, Types.INTEGER, new Type[] {storeType},
- null, new FieldRef(storeClassName, "currentId", CHRCodeGenerator.FACT_ID_TYPE), null);
- writeCurrentId = new CallJava(TVar.EMPTY_ARRAY, Types.PROC, Types.UNIT, new Type[] {storeType, Types.INTEGER},
- null, new SetFieldRef(storeClassName, "currentId", CHRCodeGenerator.FACT_ID_TYPE), null);
- if(context.module != null) // for unit testing
- context.module.addTypeDescriptor(storeType.name, new StandardTypeConstructor(storeType, TVar.EMPTY_ARRAY, storeTypeDesc));
+ readCurrentId = new CallJava(TVar.EMPTY_ARRAY, Types.PROC, Types.INTEGER, new Type[] {Types.CHRContext},
+ null, new FieldRef(CHRCodeGenerationConstants.CHRContext_name, "currentId", CHRRuntimeRulesetCodeGenerator.FACT_ID_TYPE), null);
+ writeCurrentId = new CallJava(TVar.EMPTY_ARRAY, Types.PROC, Types.UNIT, new Type[] {Types.CHRContext, Types.INTEGER},
+ null, new SetFieldRef(CHRCodeGenerationConstants.CHRContext_name, "currentId", CHRRuntimeRulesetCodeGenerator.FACT_ID_TYPE), null);
+ if(createTypeDesc && context.module != null) // for unit testing
+ context.module.addTypeDescriptor(runtimeRulesetType.name, new StandardTypeConstructor(runtimeRulesetType, TVar.EMPTY_ARRAY, runtimeRulesetTypeDesc));
}
+
+ public static final Constant ACTIVATE = new JavaMethod(true, CHRCodeGenerationConstants.CHRContext_name, "activate", Types.PROC, Types.UNIT, Types.CHRContext, Types.INTEGER);
+ private static final Constant CREATE_CHR_CONTEXT = new JavaConstructor("org/simantics/scl/runtime/chr/CHRContext", Types.PROC, Types.CHRContext);
- public void generateCode(CodeWriter w) {
- CHRRulesetObject object = new CHRRulesetObject(storeVariable, this);
+ public IVal generateCode(CodeWriter w) {
+ for(IncludeStatement include : includes) {
+ include.storeVar = include.value.toVal(cachedContext.environment, w);
+ initialPriorityNumber = Math.max(initialPriorityNumber, include.ruleset.initialPriorityNumber + include.ruleset.priorityCount);
+ }
+ CHRRulesetObject object = new CHRRulesetObject(runtimeRulesetVariable, this);
w.defineObject(object);
- for(CHRConstraint constraint : constraints) {
- //System.out.println(constraint);
- for(PrioritizedPlan plan : constraint.plans) {
+ for(CHRRule rule : rules) {
+ for(CHRSearchPlan plan : rule.plans) {
/*System.out.println(" plan " + plan.priority);
for(PlanOp planOp : plan.ops)
System.out.println(" " + planOp);*/
- PlanRealizer realizer = new PlanRealizer(cachedContext, this, storeVariable, plan.ops);
- CodeWriter methodWriter = object.createMethod(w.getModuleWriter(), TVar.EMPTY_ARRAY, Types.PROC, Types.BOOLEAN, new Type[] {constraint.factType});
+ CodeWriter methodWriter = object.createMethod(w.getModuleWriter(), TVar.EMPTY_ARRAY, Types.PROC, Types.BOOLEAN, new Type[] {Types.CHRContext, plan.constraint.factType});
plan.implementation = methodWriter.getFunction();
- plan.activeFact.setVal(methodWriter.getParameters()[0]);
+ IVal[] implementationParameters = methodWriter.getParameters();
+ plan.activeFact.setVal(implementationParameters[1]);
+ PlanRealizer realizer = new PlanRealizer(cachedContext, this, runtimeRulesetVariable, implementationParameters[0], plan.ops);
realizer.nextOp(methodWriter);
if(methodWriter.isUnfinished())
methodWriter.return_(BooleanConstant.TRUE);
}
}
+ if(!includes.isEmpty()) {
+ {
+ CodeWriter methodWriter = object.createMethod(w.getModuleWriter(), TVar.EMPTY_ARRAY, Types.PROC, Types.UNIT, new Type[] {Types.CHRContext});
+ initializer = methodWriter.getFunction();
+ for(IncludeStatement include : includes) {
+ methodWriter.apply(include.location,
+ new JavaMethod(true, runtimeRulesetClassName, "register", Types.PROC, Types.UNIT, new Type[] {runtimeRulesetType, Types.CHRContext, include.ruleset.runtimeRulesetType}),
+ object.getTarget(), methodWriter.getParameters()[0], include.storeVar);
+ }
+ methodWriter.return_(NoRepConstant.UNIT);
+ }
+ {
+ CodeWriter methodWriter = object.createMethod(w.getModuleWriter(), TVar.EMPTY_ARRAY, Types.PROC, Types.UNIT, new Type[] {Types.CHRContext});
+ deinitializer = methodWriter.getFunction();
+ for(IncludeStatement include : includes) {
+ methodWriter.apply(include.location,
+ new JavaMethod(true, runtimeRulesetClassName, "unregister", Types.PROC, Types.UNIT, new Type[] {runtimeRulesetType, Types.CHRContext, include.ruleset.runtimeRulesetType}),
+ object.getTarget(), methodWriter.getParameters()[0], include.storeVar);
+ }
+ methodWriter.return_(NoRepConstant.UNIT);
+ }
+ }
if(initConstraint != null) {
+ IVal chrContext = w.apply(location, CREATE_CHR_CONTEXT);
+ if(initializer != null) {
+ w.apply(location,
+ new JavaMethod(true, runtimeRulesetClassName, "initialize", Types.PROC, Types.UNIT, new Type[] {runtimeRulesetType, Types.CHRContext}),
+ object.getTarget(), chrContext);
+ }
IVal initFact = w.apply(location, initConstraint.constructor, IntegerConstant.ZERO);
- w.apply(location, initConstraint.addProcedure, storeVariable, initFact);
- w.apply(location, activateProcedure, storeVariable, new IntegerConstant(Integer.MAX_VALUE));
+ w.apply(location, initConstraint.addProcedure, runtimeRulesetVariable, chrContext, initFact);
+ w.apply(location, ACTIVATE, chrContext, new IntegerConstant(Integer.MAX_VALUE));
+ if(deinitializer != null) {
+ w.apply(location,
+ new JavaMethod(true, runtimeRulesetClassName, "deinitialize", Types.PROC, Types.UNIT, new Type[] {runtimeRulesetType, Types.CHRContext}),
+ object.getTarget(), chrContext);
+ }
}
+ return runtimeRulesetVariable;
}
public void collectEffects(THashSet<Type> effects) {
Code Review / simantics / platform.git / commitdiff