Add StmtContext.findFirstSubstatementArgument()

[yangtools.git] / yang / yang-parser-spi / src / main / java / org / opendaylight / yangtools / yang / parser / spi / meta / StmtContextDefaults.java

diff --git a/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/StmtContextDefaults.java b/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/StmtContextDefaults.java
new file mode 100644 (file)
index 0000000..a5692a8
--- /dev/null
+++ b/yang/yang-parser-spi/src/main/java/org/opendaylight/yangtools/yang/parser/spi/meta/StmtContextDefaults.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2020 PANTHEON.tech, s.r.o. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.yangtools.yang.parser.spi.meta;
+
+import java.util.Optional;
+import org.eclipse.jdt.annotation.NonNull;
+import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
+
+/**
+ * Default implementations for various {@link StmtContext} methods. Code hosted here is meant for use by actual
+ * {@link StmtContext} implementations, not for general use by others.
+ */
+public final class StmtContextDefaults {
+    private StmtContextDefaults() {
+        // Hidden on purpose
+    }
+
+    /**
+     * Default implementation of {@link StmtContext#findSubstatementArgument(Class)}. See that method for API contract.
+     *
+     * @param <A> Substatement argument type
+     * @param <E> Substatement effective statement representation
+     * @param stmt Statement context to search
+     * @param type Effective statement representation being look up
+     * @return Effective statement argument, if found
+     */
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public static <A, E extends EffectiveStatement<A, ?>> @NonNull Optional<A> findSubstatementArgument(
+            final @NonNull StmtContext<?, ?, ?> stmt, final @NonNull Class<E> type) {
+        return stmt.allSubstatementsStream()
+                .filter(ctx -> ((StmtContext) ctx).producesEffective(type))
+                .findAny()
+                .map(ctx -> (A) ctx.coerceStatementArgument());
+    }
+
+    /**
+     * Default implementation of {@link StmtContext#hasSubstatement(Class)}. See that method for API contract.
+     *
+     * @param stmt Statement context to search
+     * @param type Effective statement representation being look up
+     * @return True if a match is found, false otherwise
+     */
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public static boolean hasSubstatement(final @NonNull StmtContext<?, ?, ?> stmt,
+            @SuppressWarnings("rawtypes") final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
+        return stmt.allSubstatementsStream().anyMatch(ctx -> ((StmtContext) ctx).producesEffective(type));
+    }
+}