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

   1 package org.simantics.scl.compiler.elaboration.expressions;
   2
   3 import java.util.ArrayList;
   4 import java.util.List;
   5
   6 import org.simantics.scl.compiler.elaboration.chr.CHRRuleset;
   7 import org.simantics.scl.compiler.elaboration.chr.translation.CHRTranslation;
   8 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
   9 import org.simantics.scl.compiler.elaboration.expressions.block.CHRStatement;
  10 import org.simantics.scl.compiler.elaboration.expressions.block.ConstraintStatement;
  11 import org.simantics.scl.compiler.elaboration.expressions.block.GuardStatement;
  12 import org.simantics.scl.compiler.elaboration.expressions.block.IncludeStatement;
  13 import org.simantics.scl.compiler.elaboration.expressions.block.LetStatement;
  14 import org.simantics.scl.compiler.elaboration.expressions.block.RuleStatement;
  15 import org.simantics.scl.compiler.elaboration.expressions.block.Statement;
  16 import org.simantics.scl.compiler.elaboration.expressions.block.StatementGroup;
  17 import org.simantics.scl.compiler.errors.Locations;
  18
  19 public class EBlock extends ASTExpression {
  20
  21     ArrayList<Statement> statements = new ArrayList<Statement>();
  22     boolean monadic;
  23
  24     public EBlock() {
  25     }
  26
  27     public void addStatement(Statement statement) {
  28         statements.add(statement);
  29     }
  30
  31     public void setMonadic(boolean monadic) {
  32         this.monadic = monadic;
  33     }
  34
  35     public ArrayList<Statement> getStatements() {
  36         return statements;
  37     }
  38
  39     public Statement getFirst() {
  40         return statements.get(0);
  41     }
  42
  43     public Statement getLast() {
  44         return statements.get(statements.size()-1);
  45     }
  46
  47     @Override
  48     public Expression resolve(TranslationContext context) {
  49         if(statements.isEmpty()) {
  50             context.getErrorLog().log(location, "Block should not be empty.");
  51             return new EError(location);
  52         }
  53         int i = statements.size()-1;
  54         Statement last = statements.get(i);
  55         if(!(last instanceof GuardStatement)) {
  56             context.getErrorLog().log(last.location, "Block should end with an expression");
  57             return new EError(location);
  58         }
  59
  60         Expression in = ((GuardStatement)last).value;
  61         while(--i >= 0) {
  62             Statement cur = statements.get(i);
  63             StatementGroup group = cur.getStatementGroup();
  64             if(group == null)
  65                 in = cur.toExpression(context, monadic, in);
  66             else {
  67                 int endId = i+1;
  68                 while(i>0 && statements.get(i-1).getStatementGroup() == group)
  69                     --i;
  70                 switch(group) {
  71                 case LetFunction:
  72                     in = extractLet(i, endId, in);
  73                     break;
  74                 case Rule:
  75                     in = extractRules(i, endId, in);
  76                     break;
  77                 case CHR:
  78                     in = new ECHRRuleset(extractCHRRules(context, i, endId), in);
  79                     break;
  80                 }
  81             }
  82         }
  83         return in.resolve(context);
  84     }
  85
  86     private Expression extractRules(int begin, int end, Expression in) {
  87         return new EPreRuleset(statements.subList(begin, end).toArray(new RuleStatement[end-begin]), in);
  88     }
  89
  90     private CHRRuleset extractCHRRules(TranslationContext context, int begin, int end) {
  91         CHRRuleset ruleset = new CHRRuleset();
  92         ruleset.location = Locations.combine(statements.get(begin).location, statements.get(end-1).location);
  93         for(int i=begin;i<end;++i) {
  94             Statement statement = statements.get(i);
  95             if(statement instanceof CHRStatement)
  96                 ruleset.addRule(CHRTranslation.convertCHRStatement(context, (CHRStatement)statement));
  97             else if(statement instanceof ConstraintStatement)
  98                 ruleset.constraints.add(CHRTranslation.convertConstraintStatement(context, (ConstraintStatement)statement));
  99             else if(statement instanceof IncludeStatement)
 100                 ruleset.includes.add((IncludeStatement)statement);
 101             else
 102                 context.getErrorLog().log(statement.location, "Invalid CHR statement.");
 103         }
 104         return ruleset;
 105     }
 106
 107     public CHRRuleset extractCHRRules(TranslationContext context) {
 108         return extractCHRRules(context, 0, statements.size());
 109     }
 110
 111     @SuppressWarnings("unchecked")
 112     private Expression extractLet(int begin, int end, Expression in) {
 113         return new EPreLet((List<LetStatement>)(List<?>)statements.subList(begin, end), in);
 114     }
 115
 116     public static Expression create(ArrayList<Expression> statements) {
 117         EBlock block = new EBlock();
 118         for(Expression statement : statements)
 119             block.addStatement(new GuardStatement(statement));
 120         return block;
 121     }
 122
 123     @Override
 124     public void setLocationDeep(long loc) {
 125         if(location == Locations.NO_LOCATION) {
 126             location = loc;
 127             for(Statement statement : statements)
 128                 statement.setLocationDeep(loc);
 129         }
 130     }
 131
 132     @Override
 133     public Expression accept(ExpressionTransformer transformer) {
 134         return transformer.transform(this);
 135     }
 136
 137     @Override
 138     public int getSyntacticFunctionArity() {
 139         if(monadic)
 140             return 0;
 141         Statement lastStatement = statements.get(statements.size()-1);
 142         if(!(lastStatement instanceof GuardStatement))
 143             return 0;
 144         return ((GuardStatement)lastStatement).value.getSyntacticFunctionArity();
 145     }
 146
 147     @Override
 148     public void accept(ExpressionVisitor visitor) {
 149         visitor.visit(this);
 150     }
 151 }