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
  99     private void checkRuleTypes(TypingContext context) {
 100         // Create relation variables
 101         for(DatalogRule rule : rules) {
 102             Type[] parameterTypes =  rule.headRelation.getParameterTypes();
 103             Expression[] parameters = rule.headParameters;
 104             for(Variable variable : rule.variables)
 105                 variable.setType(Types.metaVar(Kinds.STAR));
 106             for(int i=0;i<parameters.length;++i)
 107                 parameters[i] = parameters[i].checkType(context, parameterTypes[i]);
 108             rule.body.checkType(context);
 109         }
 110     }
 111
 112     @Override
 113     public Expression checkBasicType(TypingContext context, Type requiredType) {
 114         checkRuleTypes(context);
 115         in = in.checkBasicType(context, requiredType);
 116         return compile(context);
 117     }
 118
 119     @Override
 120     public Expression inferType(TypingContext context) {
 121         checkRuleTypes(context);
 122         in = in.inferType(context);
 123         return compile(context);
 124     }
 125
 126     @Override
 127     public Expression checkIgnoredType(TypingContext context) {
 128         checkRuleTypes(context);
 129         in = in.checkIgnoredType(context);
 130         return compile(context);
 131     }
 132
 133     @Override
 134     public void collectFreeVariables(THashSet<Variable> vars) {
 135         for(DatalogRule rule : rules) {
 136             for(Expression parameter : rule.headParameters)
 137                 parameter.collectFreeVariables(vars);
 138             rule.body.collectFreeVariables(vars);
 139             for(Variable var : rule.variables)
 140                 vars.remove(var);
 141         }
 142         in.collectFreeVariables(vars);
 143     }
 144
 145     @Override
 146     public void collectVars(TObjectIntHashMap<Variable> allVars,
 147             TIntHashSet vars) {
 148         for(DatalogRule rule : rules) {
 149             for(Expression parameter : rule.headParameters)
 150                 parameter.collectVars(allVars, vars);
 151             rule.body.collectVars(allVars, vars);
 152         }
 153         in.collectVars(allVars, vars);
 154     }
 155
 156     @Override
 157     public void collectEffects(THashSet<Type> effects) {
 158         throw new InternalCompilerError(location, getClass().getSimpleName() + " does not support collectEffects.");
 159     }
 160
 161     @Override
 162     public Expression resolve(TranslationContext context) {
 163         throw new InternalCompilerError();
 164     }
 165
 166     static class LocalRelationAux {
 167         Variable handleFunc;
 168     }
 169
 170     public Expression compile(TypingContext context) {
 171         // Create a map from relations to their ids
 172         TObjectIntHashMap<SCLRelation> relationsToIds = new TObjectIntHashMap<SCLRelation>(relations.length,
 173                 Constants.DEFAULT_LOAD_FACTOR, -1);
 174         for(int i=0;i<relations.length;++i)
 175             relationsToIds.put(relations[i], i);
 176
 177         // Create a table from relations to the other relations they depend on
 178         TIntHashSet[] refsSets = new TIntHashSet[relations.length];
 179         int setCapacity = Math.min(Constants.DEFAULT_CAPACITY, relations.length);
 180         for(int i=0;i<relations.length;++i)
 181             refsSets[i] = new TIntHashSet(setCapacity);
 182
 183         for(DatalogRule rule : rules) {
 184             int headRelationId = relationsToIds.get(rule.headRelation);
 185             TIntHashSet refsSet = refsSets[headRelationId];
 186             rule.body.collectRelationRefs(relationsToIds, refsSet);
 187             for(Expression parameter : rule.headParameters)
 188                 parameter.collectRelationRefs(relationsToIds, refsSet);
 189         }
 190
 191         // Convert refsSets to an array
 192         final int[][] refs = new int[relations.length][];
 193         for(int i=0;i<relations.length;++i)
 194             refs[i] = refsSets[i].toArray();
 195
 196         // Find strongly connected components of the function refs
 197         final ArrayList<int[]> components = new ArrayList<int[]>();
 198
 199         new StronglyConnectedComponents(relations.length) {
 200             @Override
 201             protected void reportComponent(int[] component) {
 202                 components.add(component);
 203             }
 204
 205             @Override
 206             protected int[] findDependencies(int u) {
 207                 return refs[u];
 208             }
 209         }.findComponents();
 210
 211         // If there is just one component, compile it
 212         if(components.size() == 1) {
 213             return compileStratified(context);
 214         }
 215
 216         // Inverse of components array
 217         int[] strataPerRelation = new int[relations.length];
 218         for(int i=0;i<components.size();++i)
 219             for(int k : components.get(i))
 220                 strataPerRelation[k] = i;
 221
 222         // Collects rules belonging to each strata
 223         @SuppressWarnings("unchecked")
 224         ArrayList<DatalogRule>[] rulesPerStrata = new ArrayList[components.size()];
 225         for(int i=0;i<components.size();++i)
 226             rulesPerStrata[i] = new ArrayList<DatalogRule>();
 227         for(DatalogRule rule : rules) {
 228             int stratum = strataPerRelation[relationsToIds.get(rule.headRelation)];
 229             rulesPerStrata[stratum].add(rule);
 230         }
 231
 232         // Create stratified system
 233         Expression cur = this.in;
 234         for(int stratum=components.size()-1;stratum >= 0;--stratum) {
 235             int[] cs = components.get(stratum);
 236             LocalRelation[] curRelations = new LocalRelation[cs.length];
 237             for(int i=0;i<cs.length;++i)
 238                 curRelations[i] = relations[cs[i]];
 239             ArrayList<DatalogRule> curRules = rulesPerStrata[stratum];
 240             cur = new ERuleset(curRelations, curRules.toArray(new DatalogRule[curRules.size()]), cur).compileStratified(context);
 241         }
 242         return cur;
 243     }
 244
 245     private Expression compileStratified(TypingContext context) {
 246         Expression continuation = Expressions.tuple();
 247
 248         // Create stacks
 249         Variable[] stacks = new Variable[relations.length];
 250         for(int i=0;i<relations.length;++i) {
 251             LocalRelation relation = relations[i];
 252             Type[] parameterTypes = relation.getParameterTypes();
 253             stacks[i] = newVar("stack" + relation.getName(),
 254                     Types.apply(Names.MList_T, Types.tuple(parameterTypes))
 255                     );
 256         }
 257
 258         // Simplify subexpressions and collect derivatives
 259         THashMap<LocalRelation, Diffable> diffables = new THashMap<LocalRelation, Diffable>(relations.length);
 260         for(int i=0;i<relations.length;++i) {
 261             LocalRelation relation = relations[i];
 262             Type[] parameterTypes = relation.getParameterTypes();
 263             Variable[] parameters = new Variable[parameterTypes.length];
 264             for(int j=0;j<parameterTypes.length;++j)
 265                 parameters[j] = new Variable("p" + j, parameterTypes[j]);
 266             diffables.put(relations[i], new Diffable(i, relation, parameters));
 267         }
 268         @SuppressWarnings("unchecked")
 269         ArrayList<Expression>[] updateExpressions = (ArrayList<Expression>[])new ArrayList[relations.length];
 270         for(int i=0;i<relations.length;++i)
 271             updateExpressions[i] = new ArrayList<Expression>(2);
 272         ArrayList<Expression> seedExpressions = new ArrayList<Expression>();
 273         for(DatalogRule rule : rules) {
 274             int id = diffables.get(rule.headRelation).id;
 275             Expression appendExp = apply(context.getCompilationContext(), Types.PROC, Names.MList_add, Types.tuple(rule.headRelation.getParameterTypes()),
 276                     var(stacks[id]),
 277                     tuple(rule.headParameters)
 278                     );
 279             Diff[] diffs;
 280             try {
 281                 diffs = rule.body.derivate(diffables);
 282             } catch(DerivateException e) {
 283                 context.getErrorLog().log(e.location, "Recursion must not contain negations or aggragates.");
 284                 return new EError();
 285             }
 286             for(Diff diff : diffs)
 287                 updateExpressions[diff.id].add(((EWhen)new EWhen(rule.location, diff.query, appendExp, rule.variables).copy(context)).compile(context));
 288             if(diffs.length == 0)
 289                 seedExpressions.add(((EWhen)new EWhen(rule.location, rule.body, appendExp, rule.variables).copy(context)).compile(context));
 290             else {
 291                 Query query = rule.body.removeRelations((Set<SCLRelation>)(Set)diffables.keySet());
 292                 if(query != Query.EMPTY_QUERY)
 293                     seedExpressions.add(((EWhen)new EWhen(location, query, appendExp, rule.variables).copy(context)).compile(context));
 294             }
 295         }
 296
 297         // Iterative solving of relations
 298
 299         Variable[] loops = new Variable[relations.length];
 300         for(int i=0;i<loops.length;++i)
 301             loops[i] = newVar("loop" + relations[i].getName(), Types.functionE(Types.INTEGER, Types.PROC, Types.UNIT));
 302         continuation = seq(apply(Types.PROC, var(loops[0]), integer(relations.length-1)), continuation);
 303
 304         Expression[] loopDefs = new Expression[relations.length];
 305         for(int i=0;i<relations.length;++i) {
 306             LocalRelation relation = relations[i];
 307             Type[] parameterTypes = relation.getParameterTypes();
 308             Variable[] parameters = diffables.get(relation).parameters;
 309
 310             Variable counter = newVar("counter", Types.INTEGER);
 311
 312             Type rowType = Types.tuple(parameterTypes);
 313             Variable row = newVar("row", rowType);
 314
 315             Expression handleRow = tuple();
 316             for(Expression updateExpression : updateExpressions[i])
 317                 handleRow = seq(updateExpression, handleRow);
 318             handleRow = if_(
 319                     apply(context.getCompilationContext(), Types.PROC, Names.MSet_add, rowType,
 320                             var(relation.table), var(row)),
 321                     handleRow,
 322                     tuple()
 323                     );
 324             handleRow = seq(handleRow, apply(Types.PROC, var(loops[i]), integer(relations.length-1)));
 325             Expression failure =
 326                     if_(isZeroInteger(var(counter)),
 327                         tuple(),
 328                         apply(Types.PROC, var(loops[(i+1)%relations.length]), addInteger(var(counter), integer(-1)))
 329                        );
 330             Expression body = matchWithDefault(
 331                     apply(context.getCompilationContext(), Types.PROC, Names.MList_removeLast, rowType, var(stacks[i])),
 332                     Just(as(row, tuple(vars(parameters)))), handleRow,
 333                     failure);
 334
 335             loopDefs[i] = lambda(Types.PROC, counter, body);
 336         }
 337         continuation = letRec(loops, loopDefs, continuation);
 338
 339         // Seed relations
 340         for(Expression seedExpression : seedExpressions)
 341             continuation = seq(seedExpression, continuation);
 342
 343         // Create stacks
 344         for(int i=0;i<stacks.length;++i)
 345             continuation = let(stacks[i],
 346                     apply(context.getCompilationContext(), Types.PROC, Names.MList_create, Types.tuple(relations[i].getParameterTypes()), tuple()),
 347                     continuation);
 348
 349         continuation = ForcedClosure.forceClosure(continuation, SCLCompilerConfiguration.EVERY_DATALOG_STRATUM_IN_SEPARATE_METHOD);
 350
 351         // Create relations
 352         for(LocalRelation relation : relations)
 353             continuation = let(relation.table,
 354                     apply(context.getCompilationContext(), Types.PROC, Names.MSet_create, Types.tuple(relation.getParameterTypes()), tuple()),
 355                     continuation);
 356
 357         return seq(continuation, in);
 358     }
 359
 360     @Override
 361     protected void updateType() throws MatchException {
 362         setType(in.getType());
 363     }
 364
 365     @Override
 366     public void setLocationDeep(long loc) {
 367         if(location == Locations.NO_LOCATION) {
 368             location = loc;
 369             for(DatalogRule rule : rules)
 370                 rule.setLocationDeep(loc);
 371         }
 372     }
 373
 374     @Override
 375     public void accept(ExpressionVisitor visitor) {
 376         visitor.visit(this);
 377     }
 378
 379     public DatalogRule[] getRules() {
 380         return rules;
 381     }
 382
 383     public Expression getIn() {
 384         return in;
 385     }
 386
 387     @Override
 388     public Expression accept(ExpressionTransformer transformer) {
 389         return transformer.transform(this);
 390     }
 391
 392 }