1 files changed, 114 insertions, 0 deletions
diff --git a/java/pablotron/luigi/Parser.java b/java/pablotron/luigi/Parser.java
new file mode 100644
index 0000000..0daef25
--- /dev/null
+++ b/java/pablotron/luigi/Parser.java
@@ -0,0 +1,114 @@
+package pablotron.luigi;
+
+import java.util.ArrayList;
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+
+import pablotron.luigi.actions.Action;
+import pablotron.luigi.actions.FilterAction;
+import pablotron.luigi.actions.TextAction;
+import pablotron.luigi.FilterReference;
+import pablotron.luigi.LuigiError;
+
+public final class Parser {
+  private static final Pattern RE_ACTION = Pattern.compile(
+    // match opening brace
+    "%\\{" + 
+      
+      // match optional whitespace
+      "\\s*" + 
+
+      // match key
+      // "(?<key>[^\\s\\|\\}]+)" +
+      "([^\\s\\|\\}]+)" +
+
+      // match filter(s)
+      // "(?<filters>(\\s*\\|(\\s*[^\\s\\|\\}]+)+)*)" +
+      "((\\s*\\|(\\s*[^\\s\\|\\}]+)+)*)" +
+
+      // match optional whitespace
+      "\\s*" +
+    
+    // match closing brace
+    "\\}" +
+    
+    // or match up all non-% chars or a single % char
+    // "| (?<text>[^%]* | %)",
+    "| ([^%]* | %)",
+
+    Pattern.COMMENTS
+  );
+
+  private static final Pattern RE_FILTER = Pattern.compile(
+    // match filter name
+    // "(?<name>\\S+)" +
+    "(\\S+)" +
+  
+    // match filter arguments (optional)
+    // "(?<args>(\\s*\\S+)*)" +
+    "((\\s*\\S+)*)" +
+  
+    // optional trailing whitespace
+    "\\s*",
+
+    Pattern.COMMENTS
+  );
+
+  private static final Pattern RE_DELIM_FILTERS = Pattern.compile(
+    "\\s*\\|\\s*"
+  );
+
+  private static final Pattern RE_DELIM_ARGS = Pattern.compile(
+    "\\s+"
+  );
+
+  public static Action[] parse_template(
+    String template
+  ) throws LuigiError {
+    ArrayList<Action> r = new ArrayList<Action>();
+
+    // match on text
+    final Matcher m = RE_ACTION.matcher(template);
+
+    while (m.find()) {
+      // String key = m.group("key");
+      String key = m.group(1);
+      
+      if (key != null && key.length() > 0) {
+        // r.add(new FilterAction(key, parse_filters(m.group("filters"))));
+        r.add(new FilterAction(key, parse_filters(m.group(2))));
+      } else {
+        // r.add(new TextAction(m.group("text")));
+        r.add(new TextAction(m.group(5)));
+      }
+    }
+
+    // build array of results
+    return r.toArray(new Action[r.size()]);
+  }
+
+  public static FilterReference[] parse_filters(
+    String filters_str
+  ) throws LuigiError {
+    ArrayList<FilterReference> r = new ArrayList<FilterReference>();
+
+    // split string into individual filters and handle each one
+    for (String f: RE_DELIM_FILTERS.split(filters_str)) {
+      // trim filter string and skip empty filters
+      f = f.trim();
+      if (f.length() == 0)
+        continue;
+
+      // match on filter and check for error
+      Matcher m = RE_FILTER.matcher(f);
+      if (!m.find())
+        throw new LuigiError("invalid filter: " + f);
+
+      // append new filter reference to result
+      r.add(new FilterReference(m.group(1), RE_DELIM_ARGS.split(m.group(2))));
+    }
+
+    // return result
+    return r.toArray(new FilterReference[r.size()]);
+  }
+};