Block comment support

mirah · Oct 9, 2010 · c74f46f · c74f46f
1 parent 427d3e0
commit c74f46f
Show file tree

Hide file tree

Showing 4 changed files with 38 additions and 1 deletion.
diff --git a/jmeta/SyntaxError.java b/jmeta/SyntaxError.java
@@ -18,6 +18,9 @@ private static String makeMsg(String msg, int pos, String string, Object[] list)
             else msg = "expected "+ BaseParser.ERROR.last;
 
             String s = string.substring(pos, Math.min(pos + 13, string.length()));
+            if (pos >= string.length()) {
+              s = "<EOF>";
+            }
             int n = s.indexOf('\n');
             if (n > 0) s = s.substring(0, n);
             msg = msg + " before '"+ s +"'";

diff --git a/test/Mirah.mmeta b/test/Mirah.mmeta
@@ -55,7 +55,8 @@ parser MirahParser {
   sp: oneOf(" \t\f\r\v") | "\\" nl | comment;
   @Memo
   ws: (oneOf(" \t\f\r\v") | "\\" nl | comment)*;
-  comment: "#" (~"\n" _)*;
+  comment: "#" (~"\n" _)* | block_comment;
+  block_comment: "/*"! (block_comment | (~"*/" _))* "*/";
   start: ! prog=compstmt $EOF heredoc -> ^(Script prog);
   compstmt scope(@cond)
           : UNCOND

diff --git a/test/MirahLexer.java b/test/MirahLexer.java
@@ -39,6 +39,12 @@ private int skipWhitespace(int pos) {
           i = end;
         }
         break ws;
+      case '/':
+        if (i + 1 < end && chars[i + 1] == '*') {
+          i = skipBlockComment(i + 2);
+          break;
+        }
+        break ws;
       default:
         break ws;
       }
@@ -47,6 +53,29 @@ private int skipWhitespace(int pos) {
     return i;
   }
 
+  private int skipBlockComment(int start) {
+    int i = start;
+    while (i < end) {
+      switch(chars[i]) {
+      case '\n':
+        parser.note_newline(i);
+        break;
+      case '*':
+        if (i + 1 < end && chars[i + 1] == '/') {
+          return i + 1;
+        }
+        break;
+      case '/':
+        if (i + 1 < end && chars[i + 1] == '*') {
+          i = skipBlockComment(i + 2);
+        }
+        break;
+     }
+      i += 1;
+    }
+    throw new jmeta.SyntaxError("*/", end, string, null);
+  }
+
   private Tokens processFirstChar(int i) {
     Tokens type = null;
     if (i == end) {

diff --git a/test/test_mirah.rb b/test/test_mirah.rb
@@ -559,4 +559,8 @@ def test_return
    def test_call_assocs
     assert_parse("[Script, [FCall, puts, [[Hash, [Assoc, [Symbol, a], [Symbol, b]]]], null]]", "puts :a => :b")
    end
+
+   def test_block_comment
+     assert_parse("[Script, [Fixnum, 3]]", "/* A /* nested */ comment */3")
+   end
 end