org.snapscript.compile.validate.FunctionValidator Maven / Gradle / Ivy

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package org.snapscript.compile.validate;

import static org.snapscript.core.convert.Score.INVALID;

import java.util.List;
import java.util.Set;

import org.snapscript.core.InternalStateException;
import org.snapscript.core.ModifierType;
import org.snapscript.core.Type;
import org.snapscript.core.TypeExtractor;
import org.snapscript.core.convert.ConstraintMatcher;
import org.snapscript.core.convert.FunctionComparator;
import org.snapscript.core.convert.Score;
import org.snapscript.core.function.Function;
import org.snapscript.tree.ModifierValidator;

public class FunctionValidator {
   
   private final FunctionComparator comparator;
   private final ModifierValidator validator;
   private final TypeExtractor extractor;
   
   public FunctionValidator(ConstraintMatcher matcher, TypeExtractor extractor) {
      this.comparator = new FunctionComparator(matcher);
      this.validator = new ModifierValidator();
      this.extractor = extractor;
   }
   
   public void validate(Function function) throws Exception {
      Type type = function.getType();
      
      if(type == null) {
         throw new InternalStateException("Function '" + function + "' does not have a type");
      }
      validateModifiers(function);
   }
   
   private void validateModifiers(Function function) throws Exception {
      Type actual = function.getType();
      int modifiers = function.getModifiers();
      
      if(ModifierType.isOverride(modifiers)) {
         Set types = extractor.getTypes(actual);
         int matches = 0;
         
         for(Type type : types) {
            if(type != actual) {
               List functions = type.getFunctions();
               Score score = comparator.compare(function, functions);
               
               if(score.compareTo(INVALID) != 0) {
                  matches++;
                  break;
               }
            }
         }
         if(matches == 0) {
            throw new InternalStateException("Function '" + function + "' is not an override");
         }
      }
      validator.validate(actual, function, modifiers);
   }
   
}