Just another update

Task/Execute-a-Markov-algorithm/Java/execute-a-markov-algorithm.java

@@ -0,0 +1,63 @@
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class Markov {
+
+    public static void main(String[] args) throws IOException {
+
+        List<String[]> rules = readRules("markov_rules.txt");
+        List<String> tests = readTests("markov_tests.txt");
+
+        Pattern pattern = Pattern.compile("^([^#]*?)\\s+->\\s+(\\.?)(.*)");
+
+        for (int i = 0; i < tests.size(); i++) {
+            String origTest = tests.get(i);
+
+            List<String[]> captures = new ArrayList<>();
+            for (String rule : rules.get(i)) {
+                Matcher m = pattern.matcher(rule);
+                if (m.find()) {
+                    String[] groups = new String[m.groupCount()];
+                    for (int j = 0; j < groups.length; j++)
+                        groups[j] = m.group(j + 1);
+                    captures.add(groups);
+                }
+            }
+
+            String test = origTest;
+            String copy = test;
+            for (int j = 0; j < captures.size(); j++) {
+                String[] c = captures.get(j);
+                test = test.replace(c[0], c[2]);
+                if (c[1].equals("."))
+                    break;
+                if (!test.equals(copy)) {
+                    j = -1; // redo loop
+                    copy = test;
+                }
+            }
+            System.out.printf("%s\n%s\n\n", origTest, test);
+        }
+    }
+
+    private static List<String> readTests(String path)
+            throws IOException {
+        return Files.readAllLines(Paths.get(path), StandardCharsets.UTF_8);
+    }
+
+    private static List<String[]> readRules(String path)
+            throws IOException {
+        String ls = System.lineSeparator();
+        String lines = new String(Files.readAllBytes(Paths.get(path)), "UTF-8");
+        List<String[]> rules = new ArrayList<>();
+        for (String line : lines.split(ls + ls))
+            rules.add(line.split(ls));
+        return rules;
+    }
+}