migration

clojure/cljtest/ClojureEngine.java

@@ -0,0 +1,53 @@
+package cljtest;
+
+import clojure.lang.IFn;
+import common.Engine;
+
+import java.util.Optional;
+
+/**
+ * Clojure tests engine.
+ *
+ * @author Georgiy Korneev (kgeorgiy@kgeorgiy.info)
+ */
+public class ClojureEngine implements Engine<Object> {
+    private static final IFn HASH_MAP = ClojureScript.var("clojure.core/hash-map");
+
+    private final Optional<IFn> evaluate;
+    private final String evaluateString;
+    private final ClojureScript.F<Object> parse;
+    private final ClojureScript.F<String> toString;
+
+    public ClojureEngine(final String script, final Optional<String> evaluate, final String parse, final String toString) {
+        ClojureScript.loadScript(script);
+        this.parse = ClojureScript.function(parse, Object.class);
+        this.toString = ClojureScript.function(toString, String.class);
+
+        this.evaluate = evaluate.map(ClojureScript::var);
+        evaluateString = evaluate.map(s -> s + " ").orElse("");
+    }
+
+    @Override
+    public Result<Object> prepare(final String expression) {
+        return new Result<>(expression, ClojureScript.LOAD_STRING_IN.invoke(expression));
+    }
+
+    @Override
+    public Result<Object> parse(final String expression) {
+        return parse.call(new Result<>("\"" + expression + "\"", expression));
+    }
+
+    @Override
+    public Result<Number> evaluate(final Result<Object> prepared, final double[] vars) {
+        final Object map = HASH_MAP.invoke("x", vars[0], "y", vars[1], "z", vars[2]);
+        final String context = "(%sexpr %s)\nwhere expr = %s".formatted(evaluateString, map, prepared.context());
+        return evaluate
+                .map(f -> ClojureScript.call(f, Number.class, context, new Object[]{prepared.value(), map}))
+                .orElseGet(() -> ClojureScript.call((IFn) prepared.value(), Number.class, context, new Object[]{map}));
+    }
+
+    @Override
+    public Result<String> toString(final Result<Object> prepared) {
+        return toString.call(prepared);
+    }
+}