1 files changed, 105 insertions, 0 deletions
diff --git a/src/main/java/org/zwobble/mammoth/styles/StyleMapParser.java b/src/main/java/org/zwobble/mammoth/styles/StyleMapParser.java
new file mode 100644
index 0000000..4e18948
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/styles/StyleMapParser.java
@@ -0,0 +1,105 @@
+package org.zwobble.mammoth.styles;
+
+import com.google.common.collect.ImmutableList;
+import org.parboiled.BaseParser;
+import org.parboiled.Parboiled;
+import org.parboiled.Rule;
+import org.parboiled.parserunners.ReportingParseRunner;
+import org.parboiled.support.ParsingResult;
+import org.parboiled.support.Var;
+
+import java.util.List;
+
+import static org.zwobble.mammoth.util.MammothLists.list;
+import static org.zwobble.mammoth.util.MammothMaps.map;
+
+public class StyleMapParser extends BaseParser<Object> {
+    public static HtmlPath parseHtmlPath(String value) {
+        StyleMapParser parser = Parboiled.createParser(StyleMapParser.class);
+        ReportingParseRunner runner = new ReportingParseRunner(parser.HtmlPath());
+        ParsingResult<?> result = runner.run(value);
+        if (result.hasErrors()) {
+            // TODO: wrap in result
+            throw new RuntimeException("Parse error");
+        } else {
+            return (HtmlPath) result.valueStack.peek();
+        }
+    }
+
+    Rule HtmlPath() {
+        ListVar<HtmlPathElement> elements = new ListVar<>();
+        return Sequence(HtmlPathElements(elements), EOI, push(new HtmlPath(elements.build())));
+    }
+
+    Rule HtmlPathElements(ListVar<HtmlPathElement> elements) {
+        Var<HtmlPathElement> element = new Var<>();
+        return FirstOf(
+            Sequence(
+                HtmlPathElement(element),
+                elements.append(element),
+                ZeroOrMore(Sequence(Whitespace(), Ch('>'), Whitespace(), HtmlPathElement(element), elements.append(element)))),
+            toRule(push(ImmutableList.builder())));
+    }
+
+    Rule HtmlPathElement(Var<HtmlPathElement> element) {
+        Var<String> tagName = new Var<>();
+        ListVar<String> classNames = new ListVar<>();
+        Var<Boolean> fresh = new Var<>();
+        return Sequence(
+            TagNames(tagName),
+            ClassNames(classNames),
+            Fresh(fresh),
+            element.set(new HtmlPathElement(
+                list(tagName.get()),
+                classNames.isEmpty() ? map() : map("class", String.join(" ", classNames.build())),
+                !fresh.get())));
+    }
+
+    Rule TagNames(Var<String> tagName) {
+        return Sequence(Identifier(), tagName.set(match()));
+    }
+
+    Rule ClassNames(ListVar<String> classNames) {
+        Var<String> className = new Var<>();
+        return ZeroOrMore(Sequence(ClassName(className), classNames.append(className)));
+    }
+
+    Rule ClassName(Var<String> className) {
+        return Sequence(".", Identifier(), className.set(match()));
+    }
+
+    Rule Fresh(Var<Boolean> fresh) {
+        return Sequence(fresh.set(false), Optional(":fresh", fresh.set(true)));
+    }
+
+    Rule Identifier() {
+        return Sequence(
+            FirstOf(CharRange('a', 'z'), CharRange('A', 'Z')),
+            ZeroOrMore(FirstOf(CharRange('a', 'z'), CharRange('A', 'Z'), CharRange('0', '9'), Ch('-'), Ch('_'))));
+    }
+
+    Rule Whitespace() {
+        return ZeroOrMore(AnyOf(" \t"));
+    }
+
+    class ListVar<T> extends Var<ImmutableList.Builder<T>> {
+        boolean append(Var<T> element) {
+            if (get() == null) {
+                set(ImmutableList.builder());
+            }
+            return set(get().add(element.get()));
+        }
+
+        public List<T> build() {
+            if (get() == null) {
+                return list();
+            } else {
+                return get().build();
+            }
+        }
+
+        public boolean isEmpty() {
+            return get() == null;
+        }
+    }
+}