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

   1 package org.simantics.scl.compiler.elaboration.expressions;
   2
   3 import java.util.ArrayList;
   4
   5 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
   6 import org.simantics.scl.compiler.compilation.CompilationContext;
   7 import org.simantics.scl.compiler.elaboration.contexts.ReplaceContext;
   8 import org.simantics.scl.compiler.elaboration.contexts.SimplificationContext;
   9 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
  10 import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
  11 import org.simantics.scl.compiler.errors.Locations;
  12 import org.simantics.scl.compiler.internal.codegen.references.BoundVar;
  13 import org.simantics.scl.compiler.internal.codegen.references.IVal;
  14 import org.simantics.scl.compiler.internal.codegen.writer.CodeWriter;
  15 import org.simantics.scl.compiler.internal.codegen.writer.RecursiveDefinitionWriter;
  16 import org.simantics.scl.compiler.internal.elaboration.decomposed.DecomposedExpression;
  17 import org.simantics.scl.compiler.internal.elaboration.utils.StronglyConnectedComponents;
  18 import org.simantics.scl.compiler.types.Type;
  19 import org.simantics.scl.compiler.types.Types;
  20 import org.simantics.scl.compiler.types.exceptions.MatchException;
  21 import org.simantics.scl.compiler.types.kinds.Kinds;
  22
  23 import gnu.trove.map.hash.TObjectIntHashMap;
  24 import gnu.trove.set.hash.THashSet;
  25 import gnu.trove.set.hash.TIntHashSet;
  26
  27 /**
  28  * Generated maily from EPreLet
  29  */
  30 public class ELet extends Expression {
  31     public Assignment[] assignments;
  32     public Expression in;
  33
  34     public ELet(long loc, Assignment[] assignments, Expression in) {
  35         super(loc);
  36         this.assignments = assignments;
  37         this.in = in;
  38     }
  39
  40     @Override
  41     public void collectVars(TObjectIntHashMap<Variable> allVars,
  42             TIntHashSet vars) {
  43         for(Assignment assign : assignments)
  44             assign.value.collectVars(allVars, vars);
  45         in.collectVars(allVars, vars);
  46     }
  47
  48     @Override
  49     protected void updateType() throws MatchException {
  50         setType(in.getType());
  51     }
  52
  53     /**
  54      * Splits let
  55      */
  56     @Override
  57     public Expression simplify(SimplificationContext context) {
  58
  59         // Simplify assignments
  60         for(Assignment assignment : assignments) {
  61             assignment.value = assignment.value.simplify(context);
  62         }
  63
  64         // Find strongly connected components
  65         final TObjectIntHashMap<Variable> allVars = new TObjectIntHashMap<Variable>(
  66                 2*assignments.length, 0.5f, -1);
  67
  68         for(int i=0;i<assignments.length;++i)
  69             for(Variable var : assignments[i].pattern.getFreeVariables())
  70                 allVars.put(var, i);
  71         final boolean isRecursive[] = new boolean[assignments.length];
  72         final ArrayList<int[]> components = new ArrayList<int[]>(Math.max(10, assignments.length));
  73         new StronglyConnectedComponents(assignments.length) {
  74             @Override
  75             protected int[] findDependencies(int u) {
  76                 TIntHashSet vars = new TIntHashSet();
  77                 assignments[u].value.collectVars(allVars, vars);
  78                 if(vars.contains(u))
  79                     isRecursive[u] = true;
  80                 return vars.toArray();
  81             }
  82
  83             @Override
  84             protected void reportComponent(int[] component) {
  85                 components.add(component);
  86             }
  87
  88         }.findComponents();
  89
  90         // Simplify in
  91         Expression result = in.simplify(context);
  92
  93         // Handle each component
  94         for(int j=components.size()-1;j>=0;--j) {
  95             int[] component = components.get(j);
  96             boolean recursive = component.length > 1 || isRecursive[component[0]];
  97             if(recursive) {
  98                 Assignment[] cAssignments = new Assignment[component.length];
  99                 for(int i=0;i<component.length;++i)
 100                     cAssignments[i] = assignments[component[i]];
 101                 result = new ELet(location, cAssignments, result);
 102             }
 103             else {
 104                 Assignment assignment = assignments[component[0]];
 105                 Expression pattern = assignment.pattern;
 106
 107                 if(pattern instanceof EVariable) {
 108                     EVariable pvar = (EVariable)pattern;
 109                     result = new ESimpleLet(location, pvar.variable, assignment.value, result);
 110                 }
 111                 else {
 112                     result = new EMatch(location, new Expression[] {assignment.value},
 113                                     new Case(new Expression[] {pattern}, result));
 114                 }
 115             }
 116         }
 117
 118         return result;
 119     }
 120
 121     @Override
 122     public void collectFreeVariables(THashSet<Variable> vars) {
 123         in.collectFreeVariables(vars);
 124         for(Assignment assign : assignments)
 125             assign.value.collectFreeVariables(vars);
 126         for(Assignment assign : assignments)
 127             assign.pattern.removeFreeVariables(vars);
 128     }
 129
 130     @Override
 131     public Expression resolve(TranslationContext context) {
 132         throw new InternalCompilerError("ELet should be already resolved.");
 133     }
 134
 135     @Override
 136     public Expression replace(ReplaceContext context) {
 137         Assignment[] newAssignments = new Assignment[assignments.length];
 138         for(int i=0;i<assignments.length;++i)
 139             newAssignments[i] = assignments[i].replace(context);
 140         Expression newIn = in.replace(context);
 141         return new ELet(getLocation(), newAssignments, newIn);
 142     }
 143
 144     @Override
 145     public IVal toVal(CompilationContext context, CodeWriter w) {
 146         // Create bound variables
 147         BoundVar[] vars = new BoundVar[assignments.length];
 148         for(int i=0;i<assignments.length;++i) {
 149             Expression pattern = assignments[i].pattern;
 150             if(!(pattern instanceof EVariable))
 151                 throw new InternalCompilerError("Cannot handle pattern targets in recursive assignments.");
 152             vars[i] = new BoundVar(pattern.getType());
 153             ((EVariable)pattern).getVariable().setVal(vars[i]);
 154         }
 155
 156         // Create values
 157         RecursiveDefinitionWriter rdw = w.createRecursiveDefinition();
 158         long range = Locations.NO_LOCATION;
 159         for(Assignment assign2 : assignments) {
 160             range = Locations.combine(range, assign2.pattern.location);
 161             range = Locations.combine(range, assign2.value.location);
 162         }
 163         rdw.setLocation(range);
 164         for(int i=0;i<assignments.length;++i) {
 165             DecomposedExpression decomposed =
 166                     DecomposedExpression.decompose(context.errorLog, assignments[i].value);
 167             CodeWriter newW = rdw.createFunction(vars[i],
 168                     decomposed.typeParameters,
 169                     decomposed.effect,
 170                     decomposed.returnType,
 171                     decomposed.parameterTypes);
 172             IVal[] parameters = newW.getParameters();
 173             for(int j=0;j<parameters.length;++j)
 174                 decomposed.parameters[j].setVal(parameters[j]);
 175             newW.return_(decomposed.body.toVal(context, newW));
 176         }
 177         return in.toVal(context, w);
 178     }
 179
 180     private void checkAssignments(TypingContext context) {
 181         for(Assignment assign : assignments)
 182             assign.pattern = assign.pattern.checkTypeAsPattern(context, Types.metaVar(Kinds.STAR));
 183         for(Assignment assign : assignments)
 184             assign.value = assign.value.checkType(context, assign.pattern.getType());
 185     }
 186
 187     @Override
 188     public Expression inferType(TypingContext context) {
 189         checkAssignments(context);
 190         in = in.inferType(context);
 191         return this;
 192     }
 193
 194     @Override
 195     public Expression checkBasicType(TypingContext context, Type requiredType) {
 196         checkAssignments(context);
 197         in = in.checkType(context, requiredType);
 198         return this;
 199     }
 200
 201     @Override
 202     public Expression checkIgnoredType(TypingContext context) {
 203         checkAssignments(context);
 204         in = in.checkIgnoredType(context);
 205         return this;
 206     }
 207
 208     @Override
 209     public void collectEffects(THashSet<Type> effects) {
 210         for(Assignment assignment : assignments) {
 211             assignment.pattern.collectEffects(effects);
 212             assignment.value.collectEffects(effects);
 213         }
 214         in.collectEffects(effects);
 215     }
 216
 217     @Override
 218     public void setLocationDeep(long loc) {
 219         if(location == Locations.NO_LOCATION) {
 220             location = loc;
 221             for(Assignment assignment : assignments)
 222                 assignment.setLocationDeep(loc);
 223             in.setLocationDeep(loc);
 224         }
 225     }
 226
 227     @Override
 228     public void accept(ExpressionVisitor visitor) {
 229         visitor.visit(this);
 230     }
 231
 232     @Override
 233     public Expression accept(ExpressionTransformer transformer) {
 234         return transformer.transform(this);
 235     }
 236
 237     @Override
 238     public int getSyntacticFunctionArity() {
 239         return in.getSyntacticFunctionArity();
 240     }
 241
 242 }