Changeset 3261

Timestamp:

02/23/08 03:32:39 (10 months ago)

Author:

kris

Message:

added an unescape() function, which closes #894

Files:

• trunk/tango/text/Util.d (modified) (4 diffs)

trunk/tango/text/Util.d

@@ -81 +81 @@
-        matching (s1*, s2*, length)                 // low-level compare
-        isSpace (match)                             // is whitespace?
+        unescape(source, output)                    // convert '\' prefixes
-        layout (destination, format ...)            // featherweight printf
-        lines (str)                                 // foreach lines
@@ -965 +966 @@
-/******************************************************************************
-
+        Convert 'escaped' chars to normal ones: \t => ^t for example.
+        Supports \" \' \\ \a \b \f \n \r \t \v
+        
+******************************************************************************/
+
+T[] unescape(T) (T[] src, T[] dst = null)
+{
+        int delta;
+        auto s = src.ptr;
+        auto len = src.length;
+
+        // take a peek first to see if there's anything
+        if ((delta = indexOf (s, '\\', len)) < len)
+           {
+           // make some room if not enough provided
+           if (dst.length < src.length)
+               dst.length = src.length;
+           auto d = dst.ptr;
+
+           // copy segments over, a chunk at a time
+           do {
+              d [0 .. delta] = s [0 .. delta];
+              len -= delta;
+              s += delta;
+              d += delta;
+
+              // bogus trailing '\'
+              if (len < 2)
+                 {
+                 *d++ = '\\';
+                 len = 0;
+                 break;
+                 }
+
+              // translate \char
+              auto c = s[1];
+              switch (c)
+                     {
+                      case '\\':
+                           break;
+                      case '\'':
+                           c = '\'';
+                           break;
+                      case '"':
+                           c = '"';
+                           break;
+                      case 'a':
+                           c = '\a';
+                           break;
+                      case 'b':
+                           c = '\b';
+                           break;
+                      case 'f':
+                           c = '\f';
+                           break;
+                      case 'n':
+                           c = '\n';
+                           break;
+                      case 'r':
+                           c = '\r';
+                           break;
+                      case 't':
+                           c = '\t';
+                           break;
+                      case 'v':
+                           c = '\v';
+                           break;
+                      default:
+                           *d++ = '\\';
+                     }
+              *d++ = c;  
+              len -= 2;           
+              s += 2;
+              } while ((delta = indexOf (s, '\\', len)) < len);
+
+           // copy tail too
+           d [0 .. len] = s [0 .. len];
+           return dst [0 .. (d + len) - dst.ptr];
+           }
+        return src;
+}
+
+
+/******************************************************************************
+
-        jhash() -- hash a variable-length key into a 32-bit value
-
@@ -1246 +1332 @@
-debug (UnitTest)
-{
-//
+
-        
-        unittest
@@ -1417 +1503 @@
-        assert (repeat ("abc", 2, rep) == "abcabc");
-        assert (repeat ("", 4, rep) == "");
+
+        assert (unescape ("abc") == "abc");
+        assert (unescape ("abc\\") == "abc\\");
+        assert (unescape ("abc\\t") == "abc\t");
+        assert (unescape ("abc\\tc") == "abc\tc");
+        assert (unescape ("\\t") == "\t");
+        assert (unescape ("\\tx") == "\tx");
+        assert (unescape ("\\v\\vx") == "\v\vx");
+        assert (unescape ("abc\\t\\a\\bc") == "abc\t\a\bc");
-        }
-}