New interface and implementation to model function parameters

operator-assign.go

@@ -31,18 +31,20 @@ func evalAssign(ctx ExprContext, self *term) (v any, err error) {
 
 	if v, err = rightChild.compute(ctx); err == nil {
 		if functor, ok := v.(Functor); ok {
-			var minArgs, maxArgs int = 0, -1
-
 			funcName := rightChild.source()
-			if info, exists := ctx.GetFuncInfo(funcName); exists {
-				minArgs = info.MinArgs()
-				maxArgs = info.MaxArgs()
+			if info, exists, _ := GetFuncInfo(ctx, funcName); exists {
+				// ctx.RegisterFuncInfo(info)
+				ctx.RegisterFunc2(leftTerm.source(), info.Functor(), info.ReturnType(), info.Params())
 			} else if funcDef, ok := functor.(*funcDefFunctor); ok {
-				l := len(funcDef.params)
-				minArgs = l
-				maxArgs = l
+				paramCount := len(funcDef.params)
+				paramSpecs := make([]ExprFuncParam, paramCount)
+				for i := range paramSpecs {
+					paramSpecs[i] = newFuncParam(funcDef.params[i])
+				}
+				ctx.RegisterFunc2(leftTerm.source(), functor, typeAny, paramSpecs)
+			} else {
+				err = self.Errorf("unknown function %s()", funcName)
 			}
-			ctx.RegisterFunc(leftTerm.source(), functor, minArgs, maxArgs)
 		} else {
 			ctx.UnsafeSetVar(leftTerm.source(), v)
 		}