Fix recursive toString in Grammar, Token and Pattern

prism4j-languages/src/test/java/ru/noties/prism4j/ToStringTest.java

@@ -0,0 +1,25 @@
+package ru.noties.prism4j;
+
+import org.junit.Test;
+
+import ru.noties.prism4j.annotations.PrismBundle;
+
+@PrismBundle(includeAll = true, grammarLocatorClassName = ".GrammarLocatorToStringTest")
+public class ToStringTest {
+
+    @Test
+    public void test() {
+
+        final GrammarLocator locator = new GrammarLocatorToStringTest();
+        final Prism4j prism4j = new Prism4j(locator);
+
+        Prism4j.Grammar grammar;
+
+        for (String language : locator.languages()) {
+            grammar = prism4j.grammar(language);
+            if (grammar != null) {
+                System.err.printf("language: %s, toString: %s%n", language, ToString.toString(grammar));
+            }
+        }
+    }
+}

prism4j/src/main/java/ru/noties/prism4j/GrammarImpl.java

@@ -28,9 +28,6 @@ public List<Prism4j.Token> tokens() {
 
     @Override
     public String toString() {
-        return "GrammarImpl{" +
-                "name='" + name + '\'' +
-                ", tokens=" + tokens +
-                '}';
+        return ToString.toString(this);
     }
 }

prism4j/src/main/java/ru/noties/prism4j/PatternImpl.java

@@ -54,12 +54,6 @@ public Prism4j.Grammar inside() {
 
     @Override
     public String toString() {
-        return "PatternImpl{" +
-                "regex=" + regex +
-                ", lookbehind=" + lookbehind +
-                ", greedy=" + greedy +
-                ", alias='" + alias + '\'' +
-                ", inside=" + inside +
-                '}';
+        return ToString.toString(this);
     }
 }

prism4j/src/main/java/ru/noties/prism4j/ToString.java

@@ -0,0 +1,153 @@
+package ru.noties.prism4j;
+
+import android.support.annotation.NonNull;
+
+import java.util.HashSet;
+import java.util.Set;
+
+abstract class ToString {
+
+    @NonNull
+    static String toString(@NonNull Prism4j.Grammar grammar) {
+        final StringBuilder builder = new StringBuilder();
+        toString(builder, new CacheImpl(), grammar);
+        return builder.toString();
+    }
+
+    @NonNull
+    static String toString(@NonNull Prism4j.Token token) {
+        final StringBuilder builder = new StringBuilder();
+        toString(builder, new CacheImpl(), token);
+        return builder.toString();
+    }
+
+    @NonNull
+    static String toString(@NonNull Prism4j.Pattern pattern) {
+        final StringBuilder builder = new StringBuilder();
+        toString(builder, new CacheImpl(), pattern);
+        return builder.toString();
+    }
+
+    private ToString() {
+    }
+
+    private interface Cache {
+
+        boolean visited(@NonNull Object o);
+
+        void markVisited(@NonNull Object o);
+    }
+
+    private static void toString(@NonNull StringBuilder builder, @NonNull Cache cache, @NonNull Prism4j.Grammar grammar) {
+
+        builder
+                .append("Grammar{id=0x")
+                .append(Integer.toHexString(System.identityHashCode(grammar)))
+                .append(",name=\"")
+                .append(grammar.name())
+                .append('\"');
+
+        if (cache.visited(grammar)) {
+            builder.append(",[...]");
+        } else {
+            cache.markVisited(grammar);
+            builder.append(",tokens=[");
+            boolean first = true;
+            for (Prism4j.Token token : grammar.tokens()) {
+                if (first) {
+                    first = false;
+                } else {
+                    builder.append(',');
+                }
+                toString(builder, cache, token);
+            }
+            builder.append(']');
+        }
+
+        builder.append('}');
+    }
+
+    private static void toString(@NonNull StringBuilder builder, @NonNull Cache cache, @NonNull Prism4j.Token token) {
+
+        builder
+                .append("Token{id=0x")
+                .append(Integer.toHexString(System.identityHashCode(token)))
+                .append(",name=\"")
+                .append(token.name())
+                .append('\"');
+
+        if (cache.visited(token)) {
+            builder.append(",[...]");
+        } else {
+            cache.markVisited(token);
+            builder.append(",patterns=[");
+            boolean first = true;
+            for (Prism4j.Pattern pattern : token.patterns()) {
+                if (first) {
+                    first = false;
+                } else {
+                    builder.append(',');
+                }
+                toString(builder, cache, pattern);
+            }
+            builder.append(']');
+        }
+        builder.append('}');
+    }
+
+    private static void toString(@NonNull StringBuilder builder, @NonNull Cache cache, @NonNull Prism4j.Pattern pattern) {
+
+        builder
+                .append("Pattern{id=0x")
+                .append(Integer.toHexString(System.identityHashCode(pattern)));
+
+        if (cache.visited(pattern)) {
+            builder.append(",[...]");
+        } else {
+
+            cache.markVisited(pattern);
+
+            builder.append(",regex=\"").append(pattern.regex()).append('\"');
+
+            if (pattern.lookbehind()) {
+                builder.append(",lookbehind=true");
+            }
+
+            if (pattern.greedy()) {
+                builder.append(",greedy=true");
+            }
+
+            if (pattern.alias() != null) {
+                builder.append(",alias=\"").append(pattern.alias()).append('\"');
+            }
+
+            final Prism4j.Grammar inside = pattern.inside();
+            if (inside != null) {
+                builder.append(",inside=");
+                toString(builder, cache, inside);
+            }
+        }
+
+        builder.append('}');
+    }
+
+    private static class CacheImpl implements Cache {
+
+        private final Set<Integer> cache = new HashSet<>(3);
+
+        @Override
+        public boolean visited(@NonNull Object o) {
+            return cache.contains(key(o));
+        }
+
+        @Override
+        public void markVisited(@NonNull Object o) {
+            cache.add(key(o));
+        }
+
+        @NonNull
+        private static Integer key(@NonNull Object o) {
+            return System.identityHashCode(o);
+        }
+    }
+}

prism4j/src/main/java/ru/noties/prism4j/TokenImpl.java

@@ -28,9 +28,6 @@ public List<Prism4j.Pattern> patterns() {
 
     @Override
     public String toString() {
-        return "TokenImpl{" +
-                "name='" + name + '\'' +
-                ", patterns=" + patterns +
-                '}';
+        return ToString.toString(this);
     }
 }