diff options
Diffstat (limited to 'mcs/ilasm/scanner/StringHelper.cs')
| -rw-r--r-- | mcs/ilasm/scanner/StringHelper.cs | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/mcs/ilasm/scanner/StringHelper.cs b/mcs/ilasm/scanner/StringHelper.cs new file mode 100644 index 00000000000..e1e13e02b07 --- /dev/null +++ b/mcs/ilasm/scanner/StringHelper.cs @@ -0,0 +1,132 @@ +// StringHelper.cs
+// Author: Sergey Chaban (serge@wildwestsoftware.com)
+
+using System;
+using System.Text;
+
+namespace Mono.ILASM {
+
+ /// <summary>
+ /// </summary>
+ internal class StringHelper : StringHelperBase {
+
+ private static readonly string idChars = "_$@?`";
+
+ /// <summary>
+ /// </summary>
+ /// <param name="host"></param>
+ public StringHelper (ILTokenizer host) : base (host)
+ {
+ }
+
+
+ /// <summary>
+ /// </summary>
+ /// <returns></returns>
+ public override bool Start (char ch)
+ {
+ mode = Token.UNKNOWN;
+
+ if (Char.IsLetter (ch) || idChars.IndexOf (ch) != -1) {
+ mode = Token.ID;
+ } else if (ch == '\'') {
+ mode = Token.SQSTRING;
+ } else if (ch == '"') {
+ mode = Token.QSTRING;
+ }
+
+ return (mode != Token.UNKNOWN);
+ }
+
+
+ private static bool IsIdChar (int c)
+ {
+ char ch = (char) c;
+ return (Char.IsLetterOrDigit(ch) || idChars.IndexOf (ch) != -1);
+ }
+
+ /// <summary>
+ /// </summary>
+ /// <returns></returns>
+ public override string Build ()
+ {
+ if (mode == Token.UNKNOWN) return String.Empty;
+ int ch = 0;
+
+ ILReader reader = host.Reader;
+
+ StringBuilder idsb = new StringBuilder ();
+ if (mode == Token.SQSTRING || mode == Token.QSTRING) {
+ int term = (mode == Token.SQSTRING) ? '\'' : '"';
+ reader.Read (); // skip quote
+ for (ch = reader.Read (); ch != -1; ch = reader.Read ()) {
+ if (ch == term) {
+ break;
+ }
+
+ if (ch == '\\') {
+ ch = reader.Read ();
+
+ /*
+ * Long string can be broken across multiple lines
+ * by using '\' as the last char in line.
+ * Any white space chars between '\' and the first
+ * char on the next line are ignored.
+ */
+ if (ch == '\n') {
+ reader.SkipWhitespace ();
+ continue;
+ }
+
+ int escaped = Escape (ch);
+ if (escaped == -1) {
+ reader.Unread (ch);
+ ch = '\\';
+ } else {
+ ch = escaped;
+ }
+ }
+
+ idsb.Append((char)ch);
+ }
+ } else { // ID
+ while ((ch = reader.Read ()) != -1) {
+ if (IsIdChar (ch)) {
+ idsb.Append ((char) ch);
+ } else {
+ reader.Unread (ch);
+ break;
+ }
+ }
+ }
+ return idsb.ToString ();
+ }
+
+
+
+
+ /// <summary>
+ /// </summary>
+ /// <param name="ch"></param>
+ /// <returns></returns>
+ public static int Escape (int ch)
+ {
+ int res = -1;
+
+ if (ch >= '0' && ch <='7') {
+ //TODO : octal code
+ } else {
+ int id = "abfnrtv\"'\\".IndexOf ((char)ch);
+ if (id != -1) {
+ res = "\a\b\f\n\r\t\v\"'\\" [id];
+ }
+ }
+
+ return res;
+ }
+
+ }
+
+
+}
+
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