Improvements to SCL compiler error messages

[simantics/platform.git] / bundles / org.simantics.scl.compiler / src / org / simantics / scl / compiler / compilation / TypeChecking.java

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/compilation/TypeChecking.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/compilation/TypeChecking.java
index 667c089c3e24fe58561a674622f053a0ed6d9662..3118142df09740dce51ead4cf262f058f0b11b0b 100644 (file)
--- a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/compilation/TypeChecking.java
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/compilation/TypeChecking.java
@@ -204,6 +204,9 @@ public class TypeChecking {
 
                             Expression expression = value.getExpression();
 
+                            int errorCountBeforeTypeChecking = compilationContext.errorLog.getErrorCount();
+                            int functionArity = expression.getSyntacticFunctionArity();
+                            
                             try {
                                 ArrayList<TVar> vars = new ArrayList<TVar>();
                                 type = Types.removeForAll(type, vars);
@@ -218,6 +221,13 @@ public class TypeChecking {
                                     overloaded.assertResolved(compilationContext.errorLog);
                                 expression.getType().addPolarity(Polarity.POSITIVE);
                                 context.solveSubsumptions(expression.getLocation());
+                                
+                                if(compilationContext.errorLog.getErrorCount() != errorCountBeforeTypeChecking) {
+                                    int typeArity = Types.getArity(type); 
+                                    if(typeArity != functionArity)
+                                        compilationContext.errorLog.log(value.definitionLocation, "Possible problem: type declaration has " + typeArity + " parameter types, but function definition has " + functionArity + " parameters.");
+                                }
+                                
                                 ArrayList<EVariable> demands = context.getConstraintDemand();
                                 if(!demands.isEmpty() || !givenConstraints.isEmpty()) {
                                     ReducedConstraints red =