bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/expressions/ERuleset.java

   1 package org.simantics.scl.compiler.elaboration.expressions;
   2
   3 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.Just;
   4 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.addInteger;
   5 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.apply;
   6 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.as;
   7 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.if_;
   8 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.integer;
   9 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.isZeroInteger;
  10 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.lambda;
  11 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.let;
  12 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.letRec;
  13 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.matchWithDefault;
  14 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.newVar;
  15 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.seq;
  16 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.tuple;
  17 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.var;
  18 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.vars;
  19
  20 import java.util.ArrayList;
  21 import java.util.Set;
  22
  23 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
  24 import org.simantics.scl.compiler.common.names.Names;
  25 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
  26 import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
  27 import org.simantics.scl.compiler.elaboration.expressions.printing.ExpressionToStringVisitor;
  28 import org.simantics.scl.compiler.elaboration.query.Query;
  29 import org.simantics.scl.compiler.elaboration.query.Query.Diff;
  30 import org.simantics.scl.compiler.elaboration.query.Query.Diffable;
  31 import org.simantics.scl.compiler.elaboration.query.compilation.DerivateException;
  32 import org.simantics.scl.compiler.elaboration.relations.LocalRelation;
  33 import org.simantics.scl.compiler.elaboration.relations.SCLRelation;
  34 import org.simantics.scl.compiler.errors.Locations;
  35 import org.simantics.scl.compiler.internal.elaboration.utils.ForcedClosure;
  36 import org.simantics.scl.compiler.internal.elaboration.utils.StronglyConnectedComponents;
  37 import org.simantics.scl.compiler.top.SCLCompilerConfiguration;
  38 import org.simantics.scl.compiler.types.Type;
  39 import org.simantics.scl.compiler.types.Types;
  40 import org.simantics.scl.compiler.types.exceptions.MatchException;
  41 import org.simantics.scl.compiler.types.kinds.Kinds;
  42
  43 import gnu.trove.impl.Constants;
  44 import gnu.trove.map.hash.THashMap;
  45 import gnu.trove.map.hash.TObjectIntHashMap;
  46 import gnu.trove.set.hash.THashSet;
  47 import gnu.trove.set.hash.TIntHashSet;
  48
  49 public class ERuleset extends SimplifiableExpression {
  50     LocalRelation[] relations;
  51     DatalogRule[] rules;
  52     Expression in;
  53
  54     public ERuleset(LocalRelation[] relations, DatalogRule[] rules, Expression in) {
  55         this.relations = relations;
  56         this.rules = rules;
  57         this.in = in;
  58     }
  59
  60     public static class DatalogRule {
  61         public long location;
  62         public LocalRelation headRelation;
  63         public Expression[] headParameters;
  64         public Query body;
  65         public Variable[] variables;
  66
  67         public DatalogRule(LocalRelation headRelation, Expression[] headParameters,
  68                 Query body) {
  69             this.headRelation = headRelation;
  70             this.headParameters = headParameters;
  71             this.body = body;
  72         }
  73
  74         public DatalogRule(long location, LocalRelation headRelation, Expression[] headParameters,
  75                 Query body, Variable[] variables) {
  76             this.location = location;
  77             this.headRelation = headRelation;
  78             this.headParameters = headParameters;
  79             this.body = body;
  80             this.variables = variables;
  81         }
  82
  83         public void setLocationDeep(long loc) {
  84             this.location = loc;
  85             for(Expression parameter : headParameters)
  86                 parameter.setLocationDeep(loc);
  87             body.setLocationDeep(loc);
  88         }
  89
  90         @Override
  91         public String toString() {
  92             StringBuilder b = new StringBuilder();
  93             ExpressionToStringVisitor visitor = new ExpressionToStringVisitor(b);
  94             visitor.visit(this);
  95             return b.toString();
  96         }
  97
  98         public void forVariables(VariableProcedure procedure) {
  99             for(Expression headParameter : headParameters)
 100                 headParameter.forVariables(procedure);
 101             body.forVariables(procedure);
 102         }
 103     }
 104
 105     private void checkRuleTypes(TypingContext context) {
 106         // Create relation variables
 107         for(DatalogRule rule : rules) {
 108             Type[] parameterTypes =  rule.headRelation.getParameterTypes();
 109             Expression[] parameters = rule.headParameters;
 110             for(Variable variable : rule.variables)
 111                 variable.setType(Types.metaVar(Kinds.STAR));
 112             for(int i=0;i<parameters.length;++i)
 113                 parameters[i] = parameters[i].checkType(context, parameterTypes[i]);
 114             rule.body.checkType(context);
 115         }
 116     }
 117
 118     @Override
 119     public Expression checkBasicType(TypingContext context, Type requiredType) {
 120         checkRuleTypes(context);
 121         in = in.checkBasicType(context, requiredType);
 122         return compile(context);
 123     }
 124
 125     @Override
 126     public Expression inferType(TypingContext context) {
 127         checkRuleTypes(context);
 128         in = in.inferType(context);
 129         return compile(context);
 130     }
 131
 132     @Override
 133     public Expression checkIgnoredType(TypingContext context) {
 134         checkRuleTypes(context);
 135         in = in.checkIgnoredType(context);
 136         return compile(context);
 137     }
 138
 139     @Override
 140     public void collectFreeVariables(THashSet<Variable> vars) {
 141         for(DatalogRule rule : rules) {
 142             for(Expression parameter : rule.headParameters)
 143                 parameter.collectFreeVariables(vars);
 144             rule.body.collectFreeVariables(vars);
 145             for(Variable var : rule.variables)
 146                 vars.remove(var);
 147         }
 148         in.collectFreeVariables(vars);
 149     }
 150
 151     @Override
 152     public void collectRefs(TObjectIntHashMap<Object> allRefs,
 153             TIntHashSet refs) {
 154         for(DatalogRule rule : rules) {
 155             for(Expression parameter : rule.headParameters)
 156                 parameter.collectRefs(allRefs, refs);
 157             rule.body.collectRefs(allRefs, refs);
 158         }
 159         in.collectRefs(allRefs, refs);
 160     }
 161
 162     @Override
 163     public void collectVars(TObjectIntHashMap<Variable> allVars,
 164             TIntHashSet vars) {
 165         for(DatalogRule rule : rules) {
 166             for(Expression parameter : rule.headParameters)
 167                 parameter.collectVars(allVars, vars);
 168             rule.body.collectVars(allVars, vars);
 169         }
 170         in.collectVars(allVars, vars);
 171     }
 172
 173     @Override
 174     public void collectEffects(THashSet<Type> effects) {
 175         throw new InternalCompilerError(location, getClass().getSimpleName() + " does not support collectEffects.");
 176     }
 177
 178     @Override
 179     public Expression resolve(TranslationContext context) {
 180         throw new InternalCompilerError();
 181     }
 182
 183     static class LocalRelationAux {
 184         Variable handleFunc;
 185     }
 186
 187     public Expression compile(TypingContext context) {
 188         // Create a map from relations to their ids
 189         TObjectIntHashMap<SCLRelation> relationsToIds = new TObjectIntHashMap<SCLRelation>(relations.length,
 190                 Constants.DEFAULT_LOAD_FACTOR, -1);
 191         for(int i=0;i<relations.length;++i)
 192             relationsToIds.put(relations[i], i);
 193
 194         // Create a table from relations to the other relations they depend on
 195         TIntHashSet[] refsSets = new TIntHashSet[relations.length];
 196         int setCapacity = Math.min(Constants.DEFAULT_CAPACITY, relations.length);
 197         for(int i=0;i<relations.length;++i)
 198             refsSets[i] = new TIntHashSet(setCapacity);
 199
 200         for(DatalogRule rule : rules) {
 201             int headRelationId = relationsToIds.get(rule.headRelation);
 202             TIntHashSet refsSet = refsSets[headRelationId];
 203             rule.body.collectRelationRefs(relationsToIds, refsSet);
 204             for(Expression parameter : rule.headParameters)
 205                 parameter.collectRelationRefs(relationsToIds, refsSet);
 206         }
 207
 208         // Convert refsSets to an array
 209         final int[][] refs = new int[relations.length][];
 210         for(int i=0;i<relations.length;++i)
 211             refs[i] = refsSets[i].toArray();
 212
 213         // Find strongly connected components of the function refs
 214         final ArrayList<int[]> components = new ArrayList<int[]>();
 215
 216         new StronglyConnectedComponents(relations.length) {
 217             @Override
 218             protected void reportComponent(int[] component) {
 219                 components.add(component);
 220             }
 221
 222             @Override
 223             protected int[] findDependencies(int u) {
 224                 return refs[u];
 225             }
 226         }.findComponents();
 227
 228         // If there is just one component, compile it
 229         if(components.size() == 1) {
 230             return compileStratified(context);
 231         }
 232
 233         // Inverse of components array
 234         int[] strataPerRelation = new int[relations.length];
 235         for(int i=0;i<components.size();++i)
 236             for(int k : components.get(i))
 237                 strataPerRelation[k] = i;
 238
 239         // Collects rules belonging to each strata
 240         @SuppressWarnings("unchecked")
 241         ArrayList<DatalogRule>[] rulesPerStrata = new ArrayList[components.size()];
 242         for(int i=0;i<components.size();++i)
 243             rulesPerStrata[i] = new ArrayList<DatalogRule>();
 244         for(DatalogRule rule : rules) {
 245             int stratum = strataPerRelation[relationsToIds.get(rule.headRelation)];
 246             rulesPerStrata[stratum].add(rule);
 247         }
 248
 249         // Create stratified system
 250         Expression cur = this.in;
 251         for(int stratum=components.size()-1;stratum >= 0;--stratum) {
 252             int[] cs = components.get(stratum);
 253             LocalRelation[] curRelations = new LocalRelation[cs.length];
 254             for(int i=0;i<cs.length;++i)
 255                 curRelations[i] = relations[cs[i]];
 256             ArrayList<DatalogRule> curRules = rulesPerStrata[stratum];
 257             cur = new ERuleset(curRelations, curRules.toArray(new DatalogRule[curRules.size()]), cur).compileStratified(context);
 258         }
 259         return cur;
 260     }
 261
 262     private Expression compileStratified(TypingContext context) {
 263         Expression continuation = Expressions.tuple();
 264
 265         // Create stacks
 266         Variable[] stacks = new Variable[relations.length];
 267         for(int i=0;i<relations.length;++i) {
 268             LocalRelation relation = relations[i];
 269             Type[] parameterTypes = relation.getParameterTypes();
 270             stacks[i] = newVar("stack" + relation.getName(),
 271                     Types.apply(Names.MList_T, Types.tuple(parameterTypes))
 272                     );
 273         }
 274
 275         // Simplify subexpressions and collect derivatives
 276         THashMap<LocalRelation, Diffable> diffables = new THashMap<LocalRelation, Diffable>(relations.length);
 277         for(int i=0;i<relations.length;++i) {
 278             LocalRelation relation = relations[i];
 279             Type[] parameterTypes = relation.getParameterTypes();
 280             Variable[] parameters = new Variable[parameterTypes.length];
 281             for(int j=0;j<parameterTypes.length;++j)
 282                 parameters[j] = new Variable("p" + j, parameterTypes[j]);
 283             diffables.put(relations[i], new Diffable(i, relation, parameters));
 284         }
 285         @SuppressWarnings("unchecked")
 286         ArrayList<Expression>[] updateExpressions = (ArrayList<Expression>[])new ArrayList[relations.length];
 287         for(int i=0;i<relations.length;++i)
 288             updateExpressions[i] = new ArrayList<Expression>(2);
 289         ArrayList<Expression> seedExpressions = new ArrayList<Expression>();
 290         for(DatalogRule rule : rules) {
 291             int id = diffables.get(rule.headRelation).id;
 292             Expression appendExp = apply(context.getCompilationContext(), Types.PROC, Names.MList_add, Types.tuple(rule.headRelation.getParameterTypes()),
 293                     var(stacks[id]),
 294                     tuple(rule.headParameters)
 295                     );
 296             Diff[] diffs;
 297             try {
 298                 diffs = rule.body.derivate(diffables);
 299             } catch(DerivateException e) {
 300                 context.getErrorLog().log(e.location, "Recursion must not contain negations or aggragates.");
 301                 return new EError();
 302             }
 303             for(Diff diff : diffs)
 304                 updateExpressions[diff.id].add(((EWhen)new EWhen(rule.location, diff.query, appendExp, rule.variables).copy(context)).compile(context));
 305             if(diffs.length == 0)
 306                 seedExpressions.add(((EWhen)new EWhen(rule.location, rule.body, appendExp, rule.variables).copy(context)).compile(context));
 307             else {
 308                 Query query = rule.body.removeRelations((Set<SCLRelation>)(Set)diffables.keySet());
 309                 if(query != Query.EMPTY_QUERY)
 310                     seedExpressions.add(((EWhen)new EWhen(location, query, appendExp, rule.variables).copy(context)).compile(context));
 311             }
 312         }
 313
 314         // Iterative solving of relations
 315
 316         Variable[] loops = new Variable[relations.length];
 317         for(int i=0;i<loops.length;++i)
 318             loops[i] = newVar("loop" + relations[i].getName(), Types.functionE(Types.INTEGER, Types.PROC, Types.UNIT));
 319         continuation = seq(apply(Types.PROC, var(loops[0]), integer(relations.length-1)), continuation);
 320
 321         Expression[] loopDefs = new Expression[relations.length];
 322         for(int i=0;i<relations.length;++i) {
 323             LocalRelation relation = relations[i];
 324             Type[] parameterTypes = relation.getParameterTypes();
 325             Variable[] parameters = diffables.get(relation).parameters;
 326
 327             Variable counter = newVar("counter", Types.INTEGER);
 328
 329             Type rowType = Types.tuple(parameterTypes);
 330             Variable row = newVar("row", rowType);
 331
 332             Expression handleRow = tuple();
 333             for(Expression updateExpression : updateExpressions[i])
 334                 handleRow = seq(updateExpression, handleRow);
 335             handleRow = if_(
 336                     apply(context.getCompilationContext(), Types.PROC, Names.MSet_add, rowType,
 337                             var(relation.table), var(row)),
 338                     handleRow,
 339                     tuple()
 340                     );
 341             handleRow = seq(handleRow, apply(Types.PROC, var(loops[i]), integer(relations.length-1)));
 342             Expression failure =
 343                     if_(isZeroInteger(var(counter)),
 344                         tuple(),
 345                         apply(Types.PROC, var(loops[(i+1)%relations.length]), addInteger(var(counter), integer(-1)))
 346                        );
 347             Expression body = matchWithDefault(
 348                     apply(context.getCompilationContext(), Types.PROC, Names.MList_removeLast, rowType, var(stacks[i])),
 349                     Just(as(row, tuple(vars(parameters)))), handleRow,
 350                     failure);
 351
 352             loopDefs[i] = lambda(Types.PROC, counter, body);
 353         }
 354         continuation = letRec(loops, loopDefs, continuation);
 355
 356         // Seed relations
 357         for(Expression seedExpression : seedExpressions)
 358             continuation = seq(seedExpression, continuation);
 359
 360         // Create stacks
 361         for(int i=0;i<stacks.length;++i)
 362             continuation = let(stacks[i],
 363                     apply(context.getCompilationContext(), Types.PROC, Names.MList_create, Types.tuple(relations[i].getParameterTypes()), tuple()),
 364                     continuation);
 365
 366         continuation = ForcedClosure.forceClosure(continuation, SCLCompilerConfiguration.EVERY_DATALOG_STRATUM_IN_SEPARATE_METHOD);
 367
 368         // Create relations
 369         for(LocalRelation relation : relations)
 370             continuation = let(relation.table,
 371                     apply(context.getCompilationContext(), Types.PROC, Names.MSet_create, Types.tuple(relation.getParameterTypes()), tuple()),
 372                     continuation);
 373
 374         return seq(continuation, in);
 375     }
 376
 377     @Override
 378     protected void updateType() throws MatchException {
 379         setType(in.getType());
 380     }
 381
 382     @Override
 383     public void setLocationDeep(long loc) {
 384         if(location == Locations.NO_LOCATION) {
 385             location = loc;
 386             for(DatalogRule rule : rules)
 387                 rule.setLocationDeep(loc);
 388         }
 389     }
 390
 391     @Override
 392     public void accept(ExpressionVisitor visitor) {
 393         visitor.visit(this);
 394     }
 395
 396     public DatalogRule[] getRules() {
 397         return rules;
 398     }
 399
 400     public Expression getIn() {
 401         return in;
 402     }
 403
 404     @Override
 405     public void forVariables(VariableProcedure procedure) {
 406         for(DatalogRule rule : rules)
 407             rule.forVariables(procedure);
 408         in.forVariables(procedure);
 409     }
 410
 411     @Override
 412     public Expression accept(ExpressionTransformer transformer) {
 413         return transformer.transform(this);
 414     }
 415
 416 }