Add number predicate addon (#412)

common/addons/config-number-predicate/build.gradle.kts

@@ -0,0 +1,13 @@
+import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
+
+version = version("1.0.0")
+
+dependencies {
+    compileOnlyApi(project(":common:addons:manifest-addon-loader"))
+    api("com.dfsek", "paralithic", Versions.Libraries.paralithic)
+}
+
+
+tasks.named<ShadowJar>("shadowJar") {
+    relocate("com.dfsek.paralithic", "com.dfsek.terra.addons.numberpredicate.lib.paralithic")
+}

common/addons/config-number-predicate/src/main/java/com/dfsek/terra/addons/numberpredicate/DoublePredicateLoader.java

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+package com.dfsek.terra.addons.numberpredicate;
+
+import com.dfsek.paralithic.Expression;
+import com.dfsek.paralithic.eval.parser.Parser;
+import com.dfsek.paralithic.eval.parser.Scope;
+import com.dfsek.paralithic.eval.tokenizer.ParseException;
+import com.dfsek.tectonic.api.depth.DepthTracker;
+import com.dfsek.tectonic.api.exception.LoadException;
+import com.dfsek.tectonic.api.loader.ConfigLoader;
+import com.dfsek.tectonic.api.loader.type.TypeLoader;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.AnnotatedType;
+import java.util.function.DoublePredicate;
+
+
+public class DoublePredicateLoader implements TypeLoader<DoublePredicate> {
+    @Override
+    public DoublePredicate load(@NotNull AnnotatedType annotatedType, @NotNull Object o, @NotNull ConfigLoader configLoader,
+                                DepthTracker depthTracker) throws LoadException {
+        if (o instanceof String expressionString) {
+            Scope scope = new Scope();
+            scope.addInvocationVariable("value");
+            try {
+                Expression expression = new Parser().parse(expressionString, scope);
+                return d -> expression.evaluate(d) != 0; // Paralithic expressions treat '!= 0' as true
+            } catch(ParseException e) {
+                throw new LoadException("Failed to parse double predicate expression", e, depthTracker);
+            }
+        } else {
+            throw new LoadException("Double predicates must be defined as a string. E.g. 'value > 3'", depthTracker);
+        }
+    }
+}

common/addons/config-number-predicate/src/main/java/com/dfsek/terra/addons/numberpredicate/NumberPredicateAddon.java

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+/*
+ * Copyright (c) 2020-2021 Polyhedral Development
+ *
+ * The Terra Core Addons are licensed under the terms of the MIT License. For more details,
+ * reference the LICENSE file in this module's root directory.
+ */
+
+package com.dfsek.terra.addons.numberpredicate;
+
+import com.dfsek.tectonic.api.config.template.object.ObjectTemplate;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.function.DoublePredicate;
+import java.util.function.Supplier;
+
+import com.dfsek.terra.addons.manifest.api.AddonInitializer;
+import com.dfsek.terra.api.Platform;
+import com.dfsek.terra.api.addon.BaseAddon;
+import com.dfsek.terra.api.event.events.config.pack.ConfigPackPreLoadEvent;
+import com.dfsek.terra.api.event.functional.FunctionalEventHandler;
+import com.dfsek.terra.api.inject.annotations.Inject;
+
+public class NumberPredicateAddon implements AddonInitializer {
+    
+    @Inject
+    private Platform plugin;
+    
+    @Inject
+    private BaseAddon addon;
+    
+    @Override
+    public void initialize() {
+        plugin.getEventManager()
+              .getHandler(FunctionalEventHandler.class)
+              .register(addon, ConfigPackPreLoadEvent.class)
+              .then(event -> event.getPack().applyLoader(DoublePredicate.class, new DoublePredicateLoader()))
+              .priority(50)
+              .failThrough();
+    }
+}

common/addons/config-number-predicate/src/main/resources/terra.addon.yml

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+schema-version: 1
+contributors:
+  - Terra contributors
+id: config-number-predicate
+version: @VERSION@
+entrypoints:
+  - "com.dfsek.terra.addons.numberpredicate.NumberPredicateAddon"
+website:
+  issues: https://github.com/PolyhedralDev/Terra/issues
+  source: https://github.com/PolyhedralDev/Terra
+  docs: https://terra.polydev.org
+license: MIT License