feat(language): add support for count operator

2 files changed, 17 insertions, 11 deletions

diff --git a/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext b/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext
index ba885e3c..93d066af 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext
+++ b/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext
@@ -58,11 +58,17 @@ Consequent:
         actions+=Action ("," actions+=Action)*;
 
 Literal:
-        Atom | NegativeLiteral;
+        Atom | NegativeLiteral | CountLiteral;
 
 NegativeLiteral:
         modality=Modality? "!" atom=Atom;
 
+enum ComparisonOp:
+        LESS="<" | LESS_EQ="<=" | GREATER=">" | GREATER_EQ=">=" | EQ="=:=" | NOT_EQ="=!=" ;
+
+CountLiteral:
+        modality=Modality? "count" "{" atom=Atom "}" op=ComparisonOp threshold=INT;
+
 Action:
         AssertionAction | DeleteAction | NewAction;
 
@@ -174,7 +180,7 @@ QualifiedName hidden():
 
 Identifier:
         ID | "true" | "false" | "unknown" | "error" | "class" | "abstract" | "extends" | "enum" | "pred" |
-        "indiv" | "problem" | "new" | "delete" | "rule" | "may" | "must" | "current";
+        "indiv" | "problem" | "new" | "delete" | "rule" | "may" | "must" | "current" | "count";
 
 Integer returns ecore::EInt hidden():
         "-"? INT;
diff --git a/subprojects/language/src/main/java/tools/refinery/language/resource/DerivedVariableComputer.java b/subprojects/language/src/main/java/tools/refinery/language/resource/DerivedVariableComputer.java
index 4d19006f..b76c4bf7 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/resource/DerivedVariableComputer.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/resource/DerivedVariableComputer.java
@@ -18,11 +18,11 @@ import com.google.inject.name.Named;
 
 import tools.refinery.language.model.problem.Argument;
 import tools.refinery.language.model.problem.Atom;
+import tools.refinery.language.model.problem.CompoundLiteral;
 import tools.refinery.language.model.problem.Conjunction;
 import tools.refinery.language.model.problem.ExistentialQuantifier;
 import tools.refinery.language.model.problem.ImplicitVariable;
 import tools.refinery.language.model.problem.Literal;
-import tools.refinery.language.model.problem.NegativeLiteral;
 import tools.refinery.language.model.problem.Parameter;
 import tools.refinery.language.model.problem.ParametricDefinition;
 import tools.refinery.language.model.problem.Problem;
@@ -76,16 +76,16 @@ public class DerivedVariableComputer {
                 createVariables(conjunction, newVariables);
                 newVariables.addAll(knownVariables);
                 for (Literal literal : conjunction.getLiterals()) {
-                        if (literal instanceof NegativeLiteral negativeLiteral) {
-                                installDeriveNegativeLiteralState(negativeLiteral, newVariables);
+                        if (literal instanceof CompoundLiteral compoundLiteral) {
+                                installDerivedCompoundLiteralState(compoundLiteral, newVariables);
                         }
                 }
         }
 
-        protected void installDeriveNegativeLiteralState(NegativeLiteral negativeLiteral, Set<String> knownVariables) {
+        protected void installDerivedCompoundLiteralState(CompoundLiteral compoundLiteral, Set<String> knownVariables) {
                 Set<String> newVariables = new HashSet<>();
-                createSigletonVariablesAndCollectVariables(negativeLiteral.getAtom(), knownVariables, newVariables);
-                createVariables(negativeLiteral, newVariables);
+                createSigletonVariablesAndCollectVariables(compoundLiteral.getAtom(), knownVariables, newVariables);
+                createVariables(compoundLiteral, newVariables);
         }
 
         protected void createSigletonVariablesAndCollectVariables(Atom atom, Set<String> knownVariables,
@@ -169,9 +169,9 @@ public class DerivedVariableComputer {
                                 if (literal instanceof Atom atom) {
                                         discardDerivedAtomState(atom);
                                 }
-                                if (literal instanceof NegativeLiteral negativeLiteral) {
-                                        negativeLiteral.getImplicitVariables().clear();
-                                        discardDerivedAtomState(negativeLiteral.getAtom());
+                                if (literal instanceof CompoundLiteral compoundLiteral) {
+                                        compoundLiteral.getImplicitVariables().clear();
+                                        discardDerivedAtomState(compoundLiteral.getAtom());
                                 }
                         }
                 }