Merge pull request objectionary#3929 from maxonfjvipon/bug/objectiona…

…ry#3927/xpath-to-xnav-unhexing

bug(objectionary#3927): rewrite `StUnhex` with `Xnav`

eo-parser/src/main/java/org/eolang/parser/StUnhex.java

@@ -24,65 +24,117 @@
 package org.eolang.parser;
 
 import com.yegor256.xsline.Shift;
-import com.yegor256.xsline.StEndless;
+import com.yegor256.xsline.StClasspath;
 import com.yegor256.xsline.StEnvelope;
 import com.yegor256.xsline.StSequence;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import org.apache.commons.text.StringEscapeUtils;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
 import org.xembly.Directive;
 import org.xembly.Directives;
 
 /**
- * This {@link Shift} turns hex data inside XMIR
+ * This {@link Shift} turns hex data inside XMIR.
  * into EO-printable data.
  *
  * @since 0.29.0
  */
 final class StUnhex extends StEnvelope {
+    /**
+     * Unexing via {@link com.github.lombrozo.xnav.Xnav}.
+     */
+    static final Shift XNAV = new StSequence(
+        StUnhex.class.getSimpleName(),
+        new StXnav(
+            StUnhex.elements("number"),
+            xnav -> {
+                final double number = StUnhex.buffer(
+                    StUnhex.undash(xnav.element("o").text().orElse(""))
+                ).getDouble();
+                final Node node = xnav.node();
+                if (Double.isNaN(number) || Double.isInfinite(number)) {
+                    ((Element) node).setAttribute("skip", "");
+                } else {
+                    node.setTextContent(StUnhex.number(number));
+                }
+            }
+        ),
+        new StXnav(
+            StUnhex.elements("string"),
+            xnav -> xnav.node().setTextContent(
+                String.format(
+                    "\"%s\"",
+                    StringEscapeUtils.escapeJava(
+                        new String(
+                            StUnhex.buffer(
+                                StUnhex.undash(xnav.element("o").text().orElse(""))
+                            ).array(),
+                            StandardCharsets.UTF_8
+                        )
+                    )
+                )
+            )
+        )
+    );
 
     /**
-     * Ctor.
+     * Unhexing via {@link com.jcabi.xml.XMLDocument#xpath(String)}.
      */
-    StUnhex() {
-        super(
-            new StEndless(
-                new StSequence(
-                    StUnhex.class.getSimpleName(),
-                    new StXPath(
-                        StUnhex.xpath("number"),
-                        xml -> {
-                            final double number = StUnhex.buffer(
+    static final Shift XPATH = new StSequence(
+        StUnhex.class.getSimpleName(),
+        new StXPath(
+            StUnhex.elements("number"),
+            xml -> {
+                final double number = StUnhex.buffer(
+                    StUnhex.undash(xml.xpath("./o/text()").get(0))
+                ).getDouble();
+                final Iterable<Directive> dirs;
+                if (Double.isNaN(number) || Double.isInfinite(number)) {
+                    dirs = new Directives().attr("skip", "");
+                } else {
+                    dirs = new Directives().set(StUnhex.number(number));
+                }
+                return dirs;
+            }
+        ),
+        new StXPath(
+            StUnhex.elements("string"),
+            xml -> new Directives().set(
+                String.format(
+                    "\"%s\"",
+                    StringEscapeUtils.escapeJava(
+                        new String(
+                            StUnhex.buffer(
                                 StUnhex.undash(xml.xpath("./o/text()").get(0))
-                            ).getDouble();
-                            final Iterable<Directive> dirs;
-                            if (Double.isNaN(number) || Double.isInfinite(number)) {
-                                dirs = new Directives().attr("skip", "");
-                            } else {
-                                dirs = StUnhex.append(StUnhex.number(number));
-                            }
-                            return dirs;
-                        }
-                    ),
-                    new StXPath(
-                        StUnhex.xpath("string"),
-                        xml -> StUnhex.append(
-                            String.format(
-                                "\"%s\"",
-                                StringEscapeUtils.escapeJava(
-                                    new String(
-                                        StUnhex.buffer(
-                                            StUnhex.undash(xml.xpath("./o/text()").get(0))
-                                        ).array(),
-                                        StandardCharsets.UTF_8
-                                    )
-                                )
-                            )
+                            ).array(),
+                            StandardCharsets.UTF_8
                         )
                     )
                 )
             )
-        );
+        )
+    );
+
+    /**
+     * Unhexing via XSL.
+     */
+    static final Shift XSL = new StClasspath("/org/eolang/parser/print/unhex-data.xsl");
+
+    /**
+     * Ctor.
+     */
+    StUnhex() {
+        this(StUnhex.XNAV);
+    }
+
+    /**
+     * Base ctor.
+     * @param origin Original shift
+     */
+    StUnhex(final Shift origin) {
+        super(origin);
     }
 
     /**
@@ -142,23 +194,14 @@ private static String undash(final String txt) {
     }
 
     /**
-     * Make XPath.
+     * Find elements by XPath for given type.
      * @param type The type to match
      * @return XPath
      */
-    private static String xpath(final String type) {
+    private static String elements(final String type) {
         return String.format(
-            "(//o[@base='Q.org.eolang.%1$s' and(not(@skip)) and o[1][@base='Q.org.eolang.bytes' and not(o) and string-length(normalize-space(text()))>0]])[1]",
+            "//o[@base='Q.org.eolang.%1$s' and(not(@skip)) and o[1][@base='Q.org.eolang.bytes' and not(o) and string-length(normalize-space(text()))>0]]",
             type
         );
     }
-
-    /**
-     * Append Xemply instructions.
-     * @param after Value after
-     * @return Dirs
-     */
-    private static Iterable<Directive> append(final String after) {
-        return new Directives().set(after);
-    }
 }

eo-parser/src/main/java/org/eolang/parser/StXPath.java

@@ -39,6 +39,10 @@
  * @since 0.29.0
  */
 public final class StXPath implements Shift {
+    /**
+     * Xpath for finding first element.
+     */
+    private static final String INDEXED = "(%s)[1]";
 
     /**
      * XPath to search for.
@@ -68,22 +72,21 @@ public String uid() {
     @Override
     public XML apply(final int position, final XML xml) {
         final List<XML> nodes = xml.nodes(this.xpath);
-        if (nodes.size() > 1) {
-            throw new IllegalArgumentException(
-                String.format(
-                    "XPath '%s' returned too many elements (%d)",
-                    this.xpath, nodes.size()
-                )
+        final XML doc;
+        if (nodes.isEmpty()) {
+            doc = xml;
+        } else {
+            final Directives dirs = new Directives();
+            for (final XML node : nodes) {
+                dirs.xpath(String.format(StXPath.INDEXED, this.xpath))
+                    .strict(1)
+                    .append(this.fun.apply(node));
+            }
+            doc = new XMLDocument(
+                new Xembler(dirs).applyQuietly(xml.inner())
             );
         }
-        final Directives dirs = new Directives();
-        if (!nodes.isEmpty()) {
-            dirs.xpath(this.xpath);
-            dirs.append(this.fun.apply(nodes.get(0)));
-        }
-        return new XMLDocument(
-            new Xembler(dirs).applyQuietly(xml.deepCopy())
-        );
+        return doc;
     }
 
 }

eo-parser/src/main/java/org/eolang/parser/StXnav.java

@@ -0,0 +1,71 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2025 Objectionary.com
+ *
+ * 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.eolang.parser;
+
+import com.github.lombrozo.xnav.Xnav;
+import com.jcabi.xml.XML;
+import com.jcabi.xml.XMLDocument;
+import com.yegor256.xsline.Shift;
+import java.util.function.Consumer;
+import org.w3c.dom.Node;
+
+/**
+ * This {@link Shift} finds all XPath matches and replaces them
+ * with what a function suggests using {@link com.github.lombrozo.xnav.Xnav}.
+ *
+ * @since 0.53.0
+ */
+public final class StXnav implements Shift {
+    /**
+     * XPath to search for.
+     */
+    private final String xpath;
+
+    /**
+     * The mapping function.
+     */
+    private final Consumer<Xnav> fun;
+
+    /**
+     * Ctor.
+     * @param path The XPath
+     * @param func The function
+     */
+    public StXnav(final String path, final Consumer<Xnav> func) {
+        this.xpath = path;
+        this.fun = func;
+    }
+
+    @Override
+    public String uid() {
+        return this.getClass().getSimpleName();
+    }
+
+    @Override
+    public XML apply(final int position, final XML xml) {
+        final Node dom = xml.inner();
+        new Xnav(dom).path(this.xpath).forEach(this.fun);
+        return new XMLDocument(dom);
+    }
+}