(yegor256#1462) Add text.Mapped

src/main/java/org/cactoos/text/Mapped.java

@@ -0,0 +1,62 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2020 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.cactoos.text;
+
+import org.cactoos.Func;
+import org.cactoos.Text;
+
+/**
+ * Mapped text.
+ *
+ * @since 0.47
+ */
+public final class Mapped implements Text {
+
+    /**
+     * Map function.
+     */
+    private final Func<String, String> func;
+
+    /**
+     * Original text.
+     */
+    private final Text text;
+
+    /**
+     * Ctor.
+     *
+     * @param fnc Function to apply
+     * @param txt Original text
+     */
+    public Mapped(final Func<String, String> fnc, final Text txt) {
+        this.func = fnc;
+        this.text = txt;
+    }
+
+    @Override
+    public String asString() throws Exception {
+        return this.func.apply(this.text.asString());
+    }
+
+}

src/test/java/org/cactoos/text/MappedTest.java

@@ -0,0 +1,61 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2020 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.cactoos.text;
+
+import org.junit.jupiter.api.Test;
+import org.llorllale.cactoos.matchers.Assertion;
+import org.llorllale.cactoos.matchers.TextHasString;
+
+/**
+ * Tests for @{link Mapped}.
+ *
+ * @since 0.47
+ */
+final class MappedTest {
+
+    @Test
+    void mapsWithFormat() {
+        new Assertion<>(
+            "must apply lambda to a string",
+            new Mapped(
+                s -> String.format("<%s>", s),
+                new TextOf("hi")
+            ),
+            new TextHasString("<hi>")
+        ).affirm();
+    }
+
+    @Test
+    void maps() {
+        new Assertion<>(
+            "must apply mehtod reference to a string",
+            new Mapped(
+                String::toLowerCase,
+                new TextOf("ABC")
+            ),
+            new TextHasString("abc")
+        ).affirm();
+    }
+
+}