[core] Convert "legacy" filters directly into expressions (#11610)

Ports the specialized filter-* expressions from GL JS, adding them to src/mbgl/style/expression/compound_expression.cpp

1 files changed, 10 insertions, 2 deletions

diff --git a/src/mbgl/style/filter.cpp b/src/mbgl/style/filter.cpp
index 51aa6bcf82..2559eb4816 100644
--- a/src/mbgl/style/filter.cpp
+++ b/src/mbgl/style/filter.cpp
@@ -1,12 +1,20 @@
 #include <mbgl/style/filter.hpp>
-#include <mbgl/style/filter_evaluator.hpp>
 #include <mbgl/tile/geometry_tile_data.hpp>
 
 namespace mbgl {
 namespace style {
 
 bool Filter::operator()(const expression::EvaluationContext &context) const {
-    return FilterBase::visit(*this, FilterEvaluator { context });
+    
+    if (!this->expression) return true;
+    
+    const expression::EvaluationResult result = (*this->expression)->evaluate(context);
+    if (result) {
+        const optional<bool> typed = expression::fromExpressionValue<bool>(*result);
+        return typed ? *typed : false;
+    } else {
+        return true;
+    }
 }
 
 } // namespace style