static string Str(Node p)
{
StringBuilder s = new StringBuilder();
while (p != null)
{
if (p.typ == Node.chr)
{
s.Append((char)p.val);
}
else if (p.typ == Node.clas)
{
BitArray set = CharClass.Set(p.val);
if (Sets.Elements(set) != 1)
{
Parser.SemErr("character set contains more than 1 character");
}
s.Append((char)Sets.First(set));
}
else
{
Parser.SemErr("comment delimiters may not be structured");
}
p = p.next;
}
if (s.Length == 0 || s.Length > 2)
{
Parser.SemErr("comment delimiters must be 1 or 2 characters long");
s = new StringBuilder("?");
}
return(s.ToString());
}
//---------- String handling
static char Hex2Char(string s)
{
int val = 0;
for (int i = 0; i < s.Length; i++)
{
char ch = s[i];
if ('0' <= ch && ch <= '9')
{
val = 16 * val + (ch - '0');
}
else if ('a' <= ch && ch <= 'f')
{
val = 16 * val + (10 + ch - 'a');
}
else if ('A' <= ch && ch <= 'Z')
{
val = 16 * val + (10 + ch - 'A');
}
else
{
Parser.SemErr("bad escape sequence in string or character");
}
}
return((char)val);
}
/* ML 2002-09-07 Generates the class "Tokens" *
* which maps the token number to meaningfully named integer constants, *
* as specified in the NAMES section. */
static void GenTokens()
{
if (Symbol.tokenNames != null && Symbol.tokenNames.Count > 0)
{
gen.WriteLine("public class Tokens {");
foreach (DictionaryEntry entry in Symbol.tokenNames)
{
string token = entry.Key as string;
string name = entry.Value as string;
if (IsCSharpKW(name))
{
Parser.SemErr(name + " is a C# keyword." +
"Use another name for the token " + token);
continue;
}
Symbol sym = Symbol.Find(token);
if (sym != null && (sym.typ == Node.t || sym.typ == Node.wt))
{
gen.WriteLine("\tpublic const int {0} = {1};", name, sym.n);
}
}
gen.WriteLine("}");
}
}
public static string Unescape(string s)
{
/* replaces escape sequences in s by their Unicode values. */
StringBuilder buf = new StringBuilder();
int i = 0;
while (i < s.Length)
{
if (s[i] == '\\')
{
switch (s[i + 1])
{
case '\\': buf.Append('\\'); i += 2; break;
case '\'': buf.Append('\''); i += 2; break;
case '\"': buf.Append('\"'); i += 2; break;
case 'r': buf.Append('\r'); i += 2; break;
case 'n': buf.Append('\n'); i += 2; break;
case 't': buf.Append('\t'); i += 2; break;
case '0': buf.Append('\0'); i += 2; break;
case 'a': buf.Append('\a'); i += 2; break;
case 'b': buf.Append('\b'); i += 2; break;
case 'f': buf.Append('\f'); i += 2; break;
case 'v': buf.Append('\v'); i += 2; break;
case 'u':
case 'x':
if (i + 6 <= s.Length)
{
buf.Append(Hex2Char(s.Substring(i + 2, 4))); i += 6; break;
}
else
{
Parser.SemErr("bad escape sequence in string or character"); i = s.Length; break;
}
default: Parser.SemErr("bad escape sequence in string or character"); i += 2; break;
}
}
else
{
buf.Append(s[i]);
i++;
}
}
return(buf.ToString());
}
public static void ConvertToStates(Node p, Symbol sym)
{
curGraph = p; curSy = sym;
if (Node.DelGraph(curGraph))
{
Parser.SemErr("token might be empty");
}
NumberNodes(curGraph, firstState);
FindTrans(curGraph, true, new BitArray(Node.nodes.Count));
}
static void NewTransition(State from, State to, int typ, int sym, int tc)
{
if (to == firstState)
{
Parser.SemErr("token must not start with an iteration");
}
Target t = new Target(to);
Action a = new Action(typ, sym, tc); a.target = t;
from.AddAction(a);
}
public Symbol(int typ, string name, int line) {
if (name.Length == 2 && name[0] == '"') {
Parser.SemErr("empty token not allowed"); name = "???";
}
if (name.IndexOf(' ') >= 0) Parser.SemErr("tokens must not contain blanks");
this.typ = typ; this.name = name; this.line = line;
switch (typ) {
case Node.t: n = terminals.Count; terminals.Add(this); break;
case Node.pr: pragmas.Add(this); break;
case Node.nt: n = nonterminals.Count; nonterminals.Add(this); break;
}
}
public static Graph StrToGraph(string str) {
string s = DFA.Unescape(str.Substring(1, str.Length-2));
if (s.IndexOf('\0') >= 0) Parser.SemErr("\\0 not allowed here. Used as eof character");
if (s.Length == 0) Parser.SemErr("empty token not allowed");
Graph g = new Graph();
g.r = dummyNode;
for (int i = 0; i < s.Length; i++) {
Node p = new Node(Node.chr, (int)s[i], 0);
g.r.next = p; g.r = p;
}
g.l = dummyNode.next; dummyNode.next = null;
return g;
}
public static void MatchLiteral(Symbol sym) // store string either as token or as literal
{
string name = Unescape(sym.name.Substring(1, sym.name.Length - 2));
if (name.IndexOf('\0') >= 0)
{
Parser.SemErr("\\0 not allowed here. Used as eof character");
}
Symbol matchedSym = MatchedDFA(name, sym);
if (matchedSym == null)
{
sym.tokenKind = Symbol.classToken;
}
else
{
matchedSym.tokenKind = Symbol.classLitToken;
sym.tokenKind = Symbol.litToken;
}
}
void NewTransition(State from, State to, int typ, int sym, int tc)
{
if (to == firstState)
{
parser.SemErr("token must not start with an iteration");
}
Target t = new Target(to);
Action a = new Action(typ, sym, tc); a.target = t;
from.AddAction(a);
if (typ == Node.clas)
{
curSy.tokenKind = Symbol.classToken;
}
}
void Step(State from, Node p, BitArray stepped)
{
if (p == null)
{
return;
}
stepped[p.n] = true;
switch (p.typ)
{
case Node.clas:
case Node.chr: {
NewTransition(from, TheState(p.next), p.typ, p.val, p.code);
break;
}
case Node.alt: {
Step(from, p.sub, stepped); Step(from, p.down, stepped);
break;
}
case Node.iter: {
if (Tab.DelSubGraph(p.sub))
{
parser.SemErr("contents of {...} must not be deletable");
return;
}
if (p.next != null && !stepped[p.next.n])
{
Step(from, p.next, stepped);
}
Step(from, p.sub, stepped);
if (p.state != from)
{
Step(p.state, p, new BitArray(tab.nodes.Count));
}
break;
}
case Node.opt: {
if (p.next != null && !stepped[p.next.n])
{
Step(from, p.next, stepped);
}
Step(from, p.sub, stepped);
break;
}
}
}