Implementation of UTF-8 ranges

New constructor 'lpeg.utfR(from, to)' creates a pattern that matches
UTF-8 byte sequences representing code points in the range [from, to].

1 files changed, 12 insertions, 0 deletions

diff --git a/lpeg.html b/lpeg.html
index 8b9f59c..1295c4f 100644
--- a/lpeg.html
+++ b/lpeg.html
@@ -107,6 +107,9 @@ for creating patterns:
   <td>Matches any character in <code>string</code> (Set)</td></tr>
 <tr><td><a href="#op-r"><code>lpeg.R("<em>xy</em>")</code></a></td>
   <td>Matches any character between <em>x</em> and <em>y</em> (Range)</td></tr>
+<tr><td><a href="#op-utfR"><code>lpeg.utfR(cp1, cp2)</code></a></td>
+  <td>Matches an UTF-8 code point between <code>cp1</code> and
+  <code>cp2</code></td></tr>
 <tr><td><a href="#op-pow"><code>patt^n</code></a></td>
   <td>Matches at least <code>n</code> repetitions of <code>patt</code></td></tr>
 <tr><td><a href="#op-pow"><code>patt^-n</code></a></td>
@@ -329,6 +332,15 @@ are patterns that always fail.
 </p>
 
 
+<h3><a name="op-utfR"></a><code>lpeg.utfR (cp1, cp2)</code></h3>
+<p>
+Returns a pattern that matches a valid UTF-8 byte sequence
+representing a code point in the range <code>[cp1, cp2]</code>.
+The range is limited by the natural Unicode limit of 0x10FFFF,
+but may include surrogates.
+</p>
+
+
 <h3><a name="op-v"></a><code>lpeg.V (v)</code></h3>
 <p>
 This operation creates a non-terminal (a <em>variable</em>)