[asciidoc] Add support for hard line breaks (fix #30)

Author: fpapon

asciidoc-java/src/main/java/io/yupiik/asciidoc/parser/Parser.java

@@ -267,6 +267,10 @@ private List<Element> doParse(final Reader reader, final Predicate<String> conti
                 }
                 elements.add(new Quote(doParse(new Reader(buffer), l -> true, resolver, attributes, supportComplexStructures), options == null ? Map.of() : options));
                 options = null;
+            } else if (stripped.endsWith(" +")) {
+                elements.addAll(parseLine(reader, stripped.substring(0, stripped.length()-2), resolver, attributes, supportComplexStructures));
+                elements.add(new LineBreak());
+                options = null;
             } else if (stripped.startsWith(":") && (attributeMatcher = ATTRIBUTE_DEFINITION.matcher(stripped)).matches()) {
                 final var value = attributeMatcher.groupCount() == 3 ? ofNullable(attributeMatcher.group("value")).orElse("") : "";
                 final var name = attributeMatcher.group("name");

asciidoc-java/src/test/java/io/yupiik/asciidoc/parser/ParserTest.java

@@ -24,6 +24,7 @@
 import io.yupiik.asciidoc.model.ConditionalBlock;
 import io.yupiik.asciidoc.model.DescriptionList;
 import io.yupiik.asciidoc.model.Element;
+import io.yupiik.asciidoc.model.LineBreak;
 import io.yupiik.asciidoc.model.Link;
 import io.yupiik.asciidoc.model.Macro;
 import io.yupiik.asciidoc.model.OpenBlock;
@@ -1263,4 +1264,19 @@ void icon() {
                 List.of(new Macro("icon", "heart", Map.of("size", "2x"), true)),
                 new Parser().parseBody(new Reader(List.of("icon:heart[size=2x]")), null).children());
     }
+
+    @Test
+    void hardbreak() {
+        final var body = new Parser().parseBody(new Reader(List.of("""
+                Rubies are red, +
+                Topazes are blue.
+                """.split("\n"))), null);
+        assertEquals(
+                List.of(new Text(List.of(), "Rubies are red,", Map.of()),
+                        new LineBreak(),
+                        new Text(List.of(), "Topazes are blue.", Map.of())),
+                body.children());
+    }
+
+
 }