protected internal override object GetInstanceIdValue(int id)
{
int shifted = id - base.MaxInstanceId;
if (1 <= shifted && shifted <= MAX_INSTANCE_ID)
{
RegExpImpl impl = Impl;
object stringResult;
switch (shifted)
{
case Id_multiline:
case Id_STAR:
return(impl.multiline);
case Id_input:
case Id_UNDERSCORE:
stringResult = impl.input;
break;
case Id_lastMatch:
case Id_AMPERSAND:
stringResult = impl.lastMatch;
break;
case Id_lastParen:
case Id_PLUS:
stringResult = impl.lastParen;
break;
case Id_leftContext:
case Id_BACK_QUOTE:
stringResult = impl.leftContext;
break;
case Id_rightContext:
case Id_QUOTE:
stringResult = impl.rightContext;
break;
default: {
// Must be one of $1..$9, convert to 0..8
int substring_number = shifted - DOLLAR_ID_BASE - 1;
stringResult = impl.getParenSubString(substring_number);
break;
}
}
return((stringResult == null) ? "" : stringResult.ToString());
}
return(base.GetInstanceIdValue(id));
}
private static SubString interpretDollar (Context cx, RegExpImpl res, string da, int dp, int [] skip)
{
char dc;
int num, tmp;
if (da [dp] != '$')
Context.CodeBug ();
/* Allow a real backslash (literal "\\") to escape "$1" etc. */
Context.Versions version = cx.Version;
if (version != Context.Versions.Default && version <= Context.Versions.JS1_4) {
if (dp > 0 && da [dp - 1] == '\\')
return null;
}
int daL = da.Length;
if (dp + 1 >= daL)
return null;
/* Interpret all Perl match-induced dollar variables. */
dc = da [dp + 1];
if (BuiltinRegExp.isDigit (dc)) {
int cp;
if (version != Context.Versions.Default && version <= Context.Versions.JS1_4) {
if (dc == '0')
return null;
/* Check for overflow to avoid gobbling arbitrary decimal digits. */
num = 0;
cp = dp;
while (++cp < daL && BuiltinRegExp.isDigit (dc = da [cp])) {
tmp = 10 * num + (dc - '0');
if (tmp < num)
break;
num = tmp;
}
}
else {
/* ECMA 3, 1-9 or 01-99 */
int parenCount = (res.parens == null) ? 0 : res.parens.Length;
num = dc - '0';
if (num > parenCount)
return null;
cp = dp + 2;
if ((dp + 2) < daL) {
dc = da [dp + 2];
if (BuiltinRegExp.isDigit (dc)) {
tmp = 10 * num + (dc - '0');
if (tmp <= parenCount) {
cp++;
num = tmp;
}
}
}
if (num == 0)
return null; /* $0 or $00 is not valid */
}
/* Adjust num from 1 $n-origin to 0 array-index-origin. */
num--;
skip [0] = cp - dp;
return res.getParenSubString (num);
}
skip [0] = 2;
switch (dc) {
case '$':
return new SubString ("$");
case '&':
return res.lastMatch;
case '+':
return res.lastParen;
case '`':
if (version == Context.Versions.JS1_2) {
/*
* JS1.2 imitated the Perl4 bug where left context at each step
* in an iterative use of a global regexp started from last match,
* not from the start of the target string. But Perl4 does start
* $` at the beginning of the target string when it is used in a
* substitution, so we emulate that special case here.
*/
res.leftContext.index = 0;
res.leftContext.length = res.lastMatch.index;
}
return res.leftContext;
case '\'':
return res.rightContext;
}
return null;
}
private static SubString interpretDollar(Context cx, RegExpImpl res, string da, int dp, int [] skip)
{
char dc;
int num, tmp;
if (da [dp] != '$')
{
Context.CodeBug();
}
/* Allow a real backslash (literal "\\") to escape "$1" etc. */
Context.Versions version = cx.Version;
if (version != Context.Versions.Default && version <= Context.Versions.JS1_4)
{
if (dp > 0 && da [dp - 1] == '\\')
{
return(null);
}
}
int daL = da.Length;
if (dp + 1 >= daL)
{
return(null);
}
/* Interpret all Perl match-induced dollar variables. */
dc = da [dp + 1];
if (BuiltinRegExp.isDigit(dc))
{
int cp;
if (version != Context.Versions.Default && version <= Context.Versions.JS1_4)
{
if (dc == '0')
{
return(null);
}
/* Check for overflow to avoid gobbling arbitrary decimal digits. */
num = 0;
cp = dp;
while (++cp < daL && BuiltinRegExp.isDigit(dc = da [cp]))
{
tmp = 10 * num + (dc - '0');
if (tmp < num)
{
break;
}
num = tmp;
}
}
else
{
/* ECMA 3, 1-9 or 01-99 */
int parenCount = (res.parens == null) ? 0 : res.parens.Length;
num = dc - '0';
if (num > parenCount)
{
return(null);
}
cp = dp + 2;
if ((dp + 2) < daL)
{
dc = da [dp + 2];
if (BuiltinRegExp.isDigit(dc))
{
tmp = 10 * num + (dc - '0');
if (tmp <= parenCount)
{
cp++;
num = tmp;
}
}
}
if (num == 0)
{
return(null); /* $0 or $00 is not valid */
}
}
/* Adjust num from 1 $n-origin to 0 array-index-origin. */
num--;
skip [0] = cp - dp;
return(res.getParenSubString(num));
}
skip [0] = 2;
switch (dc)
{
case '$':
return(new SubString("$"));
case '&':
return(res.lastMatch);
case '+':
return(res.lastParen);
case '`':
if (version == Context.Versions.JS1_2)
{
/*
* JS1.2 imitated the Perl4 bug where left context at each step
* in an iterative use of a global regexp started from last match,
* not from the start of the target string. But Perl4 does start
* $` at the beginning of the target string when it is used in a
* substitution, so we emulate that special case here.
*/
res.leftContext.index = 0;
res.leftContext.length = res.lastMatch.index;
}
return(res.leftContext);
case '\'':
return(res.rightContext);
}
return(null);
}