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Cursor.cs
667 lines (553 loc) · 19.1 KB
/
Cursor.cs
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using Niecza;
using System;
using System.Collections.Generic;
using System.Text;
// this exists to allow O(1) addition, since additions (esp. in the presence
// of backtracking) dominate lookups
public class Matched {
public Matched next;
public string name;
public Variable val; // or null for a list-mode sentinel
public Matched(Matched next, string name, Variable val) {
this.next = next;
this.name = name;
this.val = val;
}
}
//
//public class Match {
// public string backing;
// public int from;
// public int to;
// public Dictionary<string,Variable> captures;
//}
//
//public class Xact {
//
public class Cursor {
// XXX It's a bit wrong that we ref the string both from the cursor and
// from $*ORIG.
public Matched captures;
public string backing;
public int pos;
public Cursor(Matched captures, string backing, int pos) {
this.captures = captures;
this.backing = backing;
this.pos = pos;
}
public Cursor(string backing) : this(null, backing, 0) { }
public Cursor At(int npos) {
return new Cursor(captures, backing, npos);
}
public Cursor Exact(string what) {
if (backing.Length - what.Length >= pos &&
backing.Substring(pos, what.Length) == what) {
return At(pos + what.Length);
} else {
return null;
}
}
public Cursor SetCaps(Matched caps) {
return new Cursor(caps, backing, pos);
}
public Cursor Bind(string name, Variable what) {
return SetCaps(new Matched(captures, name, what));
}
public Cursor SimpleWS() {
int l = backing.Length;
int p = pos;
if (p != 0 && p != l && !Char.IsWhiteSpace(backing, p) &&
!Char.IsWhiteSpace(backing, p-1)) {
return null;
}
while (p != l && Char.IsWhiteSpace(backing, p)) { p++; }
return At(p);
}
}
public sealed class CCTerm {
public readonly int catmask;
// these should probably be inversion lists
public readonly char[] butyes;
public readonly char[] butno;
public CCTerm(int catmask, char[] butyes, char[] butno) {
this.catmask = catmask; this.butyes = butyes; this.butno = butno;
}
public CCTerm(char[] butyes) : this(0, butyes, new char[0]{}) { }
public CCTerm(char butyes) : this(0, new char[1] { butyes },
new char[0] {}) { }
public CCTerm(int catmask) : this(catmask, new char[0] {}, new char[0]{}) {}
public bool Accepts(char ch) {
foreach (char y in butyes)
if (y == ch)
return true;
foreach (char n in butno)
if (n == ch)
return false;
return (catmask & (1 << ((int)char.GetUnicodeCategory(ch)))) != 0;
}
public const int Alpha = 0x1F;
public const int Mark = 0xE0;
public const int Num = 0x700;
public const int Space = 0x3800;
public const int Control = 0x3C000;
public const int Punct = 0x1FC0000;
public const int Symbol = 0x1E000000;
public const int Other = 0x20000000;
public const int AlNum = Alpha | Num;
private static readonly string[] categories = new string[] {
"Lu", "Ll", "Lt", "Lm", "Lo", "Mn", "Mc", "Me",
"Nd", "Nl", "No", "Zs", "Zl", "Zp", "Cc", "Cf",
"Cs", "Co", "Pc", "Pd", "Ps", "Pe", "Pi", "Pf",
"Po", "Sm", "Sc", "Sk", "So", "Cn"
};
public override string ToString() {
string o = "";
if (catmask == 0x3FFFFFFF) {
o = "+any";
} else {
for (int c = 0; c <= 29; c++) {
if ((catmask & (1 << c)) != 0) {
o += "+is" + categories[c];
}
}
}
foreach (char c in butyes) {
o += "+[" + c + "]";
}
foreach (char c in butno) {
o += "-[" + c + "]";
}
return o;
}
}
public sealed class NFA {
public sealed class Node {
public int fate;
public bool final;
public List<Edge> edges = new List<Edge>();
public Node(int curfate) { fate = curfate; }
public override string ToString() {
return "(" + fate + ")" + (final ? "+ " : " ") +
Kernel.JoinS(", ", edges);
}
}
public sealed class Edge {
public int to;
public CCTerm when; // null if epsilon
public override string ToString() {
return ((when != null) ? when.ToString() : "ε") + " => " + to;
}
}
public List<Node> nodes = new List<Node>();
public int curfate;
public DynMetaObject cursor_class;
public HashSet<string> method_stack = new HashSet<string>();
public Dictionary<string,LAD> method_cache = new Dictionary<string,LAD>();
public LAD ResolveMethod(string name) {
LAD sub = null;
if (method_cache.TryGetValue(name, out sub))
return sub;
IP6 method = cursor_class.Can(name);
if (Lexer.LtmTrace && method != null)
Console.WriteLine("+ Found method");
sub = ((SubInfo)(((DynObject)method).slots["info"])).ltm;
if (Lexer.LtmTrace)
Console.WriteLine("+ {0} to sub-automaton",
(sub != null ? "Resolved" : "Failed to resolve"));
method_cache[name] = sub;
return sub;
}
public int AddNode() {
nodes.Add(new Node(curfate));
return nodes.Count - 1;
}
public void AddEdge(int from, int to, CCTerm when) {
Edge e = new Edge();
e.to = to;
e.when = when;
nodes[from].edges.Add(e);
}
public void Dump() {
for (int ix = 0; ix < nodes.Count; ix++) {
Console.WriteLine(ix + ": " + nodes[ix].ToString());
}
}
}
// ltm automaton descriptors
public abstract class LAD {
public abstract void ToNFA(NFA pad, int from, int to);
public abstract void Dump(int indent);
public virtual void QueryLiteral(NFA pad, out int len, out bool cont) {
len = 0; cont = false;
}
}
public class LADStr : LAD {
public readonly string text;
public LADStr(string text) { this.text = text; }
public override void QueryLiteral(NFA pad, out int len, out bool cont) {
len = text.Length; cont = true;
}
public override void ToNFA(NFA pad, int from, int to) {
if (text.Length == 0) {
pad.AddEdge(from, to, null);
} else {
int len = text.Length;
for (int c = 0; c < len; c++) {
int fromp = (c == len - 1) ? to : pad.AddNode();
pad.AddEdge(from, fromp, new CCTerm(text[c]));
from = fromp;
}
}
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "str: " + text);
}
}
public class LADCC : LAD {
public readonly CCTerm[] cc;
public LADCC(CCTerm[] cc) { this.cc = cc; }
public override void ToNFA(NFA pad, int from, int to) {
foreach (CCTerm t in cc) {
pad.AddEdge(from, to, t);
}
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "cc: " + cc.ToString());
}
}
public class LADStar : LAD {
public readonly LAD child;
public LADStar(LAD child) { this.child = child; }
public override void ToNFA(NFA pad, int from, int to) {
int knot = pad.AddNode();
pad.AddEdge(from, knot, null);
pad.AddEdge(knot, to, null);
child.ToNFA(pad, knot, knot);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "star:");
child.Dump(indent + 4);
}
}
public class LADOpt : LAD {
public readonly LAD child;
public LADOpt(LAD child) { this.child = child; }
public override void ToNFA(NFA pad, int from, int to) {
pad.AddEdge(from, to, null);
child.ToNFA(pad, from, to);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "opt:");
child.Dump(indent + 4);
}
}
public class LADPlus : LAD {
public readonly LAD child;
public LADPlus(LAD child) { this.child = child; }
public override void QueryLiteral(NFA pad, out int len, out bool cont) {
child.QueryLiteral(pad, out len, out cont);
}
public override void ToNFA(NFA pad, int from, int to) {
int knot1 = pad.AddNode();
int knot2 = pad.AddNode();
pad.AddEdge(from, knot1, null);
pad.AddEdge(knot2, to, null);
pad.AddEdge(knot2, knot1, null);
child.ToNFA(pad, knot1, knot2);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "plus:");
child.Dump(indent + 4);
}
}
public class LADSequence : LAD {
public readonly LAD fst;
public readonly LAD snd;
public LADSequence(LAD fst, LAD snd) { this.fst = fst; this.snd = snd; }
public override void QueryLiteral(NFA pad, out int len, out bool cont) {
fst.QueryLiteral(pad, out len, out cont);
if (cont) {
int l1 = len;
snd.QueryLiteral(pad, out len, out cont);
len += l1;
}
}
public override void ToNFA(NFA pad, int from, int to) {
int knot = pad.AddNode();
fst.ToNFA(pad, from, knot);
snd.ToNFA(pad, knot, to);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "seq:");
fst.Dump(indent + 4);
snd.Dump(indent + 4);
}
}
public class LADAny : LAD {
public readonly LAD[] zyg;
public LADAny(LAD[] zyg) { this.zyg = zyg; }
public override void ToNFA(NFA pad, int from, int to) {
foreach (LAD k in zyg)
k.ToNFA(pad, from, to);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "any:");
foreach (LAD k in zyg)
k.Dump(indent + 4);
}
}
public class LADImp : LAD {
public override void ToNFA(NFA pad, int from, int to) {
int knot = pad.AddNode();
pad.nodes[knot].final = true;
pad.AddEdge(from, knot, null);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "imp");
}
}
public class LADNull : LAD {
public override void ToNFA(NFA pad, int from, int to) {
pad.AddEdge(from, to, null);
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "null");
}
public override void QueryLiteral(NFA pad, out int len, out bool cont) {
len = 0; cont = true;
}
}
public class LADMethod : LAD {
public readonly string name;
public LADMethod(string name) { this.name = name; }
public override void ToNFA(NFA pad, int from, int to) {
if (Lexer.LtmTrace)
Console.WriteLine("+ Processing subrule {0}", name);
if (pad.method_stack.Contains(name)) {
// NFAs cannot be recursive, so treat this as the end of the
// declarative prefix.
if (Lexer.LtmTrace)
Console.WriteLine("+ Pruning to avoid recursion");
int knot = pad.AddNode();
pad.AddEdge(from, knot, null);
pad.nodes[knot].final = true;
return;
}
pad.method_stack.Add(name);
LAD sub = pad.ResolveMethod(name);
if (sub == null) {
int knot = pad.AddNode();
pad.AddEdge(from, knot, null);
pad.nodes[knot].final = true;
} else {
sub.ToNFA(pad, from, to);
}
pad.method_stack.Remove(name);
}
public override void QueryLiteral(NFA pad, out int len, out bool cont) {
LAD sub = pad.ResolveMethod(name);
if (pad.method_stack.Contains(name)) {
len = 0; cont = false;
} else {
pad.method_stack.Add(name);
sub.QueryLiteral(pad, out len, out cont);
pad.method_stack.Remove(name);
}
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "methodcall " + name);
}
}
public class LADProtoRegex : LAD {
public readonly string name;
public LADProtoRegex(string name) { this.name = name; }
public override void ToNFA(NFA pad, int from, int to) {
foreach (DynObject cand in Lexer.ResolveProtoregex(pad.cursor_class, name)) {
((SubInfo)cand.slots["info"]).ltm.ToNFA(pad, from, to);
}
}
public override void Dump(int indent) {
Console.WriteLine(new string(' ', indent) + "protorx " + name);
}
}
// These objects get put in hash tables, so don't change nstates[] after
// that happens
public class LexerState {
public int[] nstates;
public readonly Lexer parent;
public LexerState(Lexer parent) {
this.parent = parent;
this.nstates = new int[parent.pad.nodes.Count];
}
public bool alive;
// But these cachey fields are fair game
// note there will be no epsilons here
public List<NFA.Edge> alledges = new List<NFA.Edge>();
public override int GetHashCode() {
int o = 0;
for (int i = 0; i < nstates.Length; i++)
o = o * 1342883 + nstates[i];
return o;
}
public void AddNFAState(int num) {
Stack<int> grey = new Stack<int>();
grey.Push(num);
alive = true;
while (grey.Count != 0) {
int val = grey.Pop();
int vm = 1 << (val & 31);
if ((nstates[val >> 5] & vm) != 0)
continue;
nstates[val >> 5] |= vm;
foreach (NFA.Edge e in parent.pad.nodes[val].edges) {
if (e.when == null)
grey.Push(e.to);
else
alledges.Add(e);
}
}
}
public void CollectFates(Stack<int> f) {
for (int i = parent.pad.nodes.Count - 1; i >= 0; i--) {
if ((nstates[i >> 5] & (1 << (i & 31))) != 0) {
NFA.Node n = parent.pad.nodes[i];
if (n.final) {
if (Lexer.LtmTrace)
Console.WriteLine("+ Adding fate {0}", n.fate);
f.Push(n.fate);
}
}
}
}
public override string ToString() {
List<int> li = new List<int>();
for (int i = 0; i < nstates.Length; i++)
for (int j = 0; j < 32; j++) {
if ((nstates[i] & (1 << j)) == 0)
continue;
li.Add(32*i + j);
}
return Kernel.JoinS("|", li);
}
}
public class Lexer {
public LAD[] alts;
public NFA pad = new NFA();
public string tag;
public static bool LtmTrace =
Environment.GetEnvironmentVariable("NIECZA_LTM_TRACE") != null;
public Lexer(IP6 cursorObj, string tag, LAD[] alts) {
pad.cursor_class = ((DynObject)cursorObj).klass;
this.alts = alts;
this.tag = tag;
int root = pad.AddNode();
int[] alt_shuffle = new int[alts.Length];
for (int i = 0; i < alts.Length; i++) alt_shuffle[i] = i;
Array.Sort(alt_shuffle, delegate (int i1, int i2) {
int j1, j2;
bool c1, c2;
alts[i1].QueryLiteral(pad, out j1, out c1);
alts[i2].QueryLiteral(pad, out j2, out c2);
return (j1 != j2) ? (j2 - j1) : (i1 - i2);
});
for (int ix = 0; ix < alts.Length; ix++) {
pad.curfate = alt_shuffle[ix];
int target = pad.AddNode();
pad.nodes[target].final = true;
alts[alt_shuffle[ix]].ToNFA(pad, root, target);
}
// now the NFA nodes are all in tiebreak order by lowest index
if (LtmTrace) {
Dump();
}
}
public void Dump() {
Console.WriteLine("--- LEXER ({0}) : Tree", tag);
for (int ix = 0; ix < alts.Length; ix++) {
Console.WriteLine("{0}:", ix);
alts[ix].Dump(0);
}
Console.WriteLine("--- NFA:");
pad.Dump();
Console.WriteLine("--- END");
}
public int[] Run(string from, int pos) {
LexerState state = new LexerState(this);
state.AddNFAState(0);
Stack<int> fate = new Stack<int>();
if (LtmTrace)
Console.WriteLine("+ Trying lexer {0} at {1}", tag, pos);
while (true) {
state.CollectFates(fate);
if (pos == from.Length || !state.alive) break;
char ch = from[pos++];
if (LtmTrace)
Console.WriteLine("+ Adding character {0}", ch);
LexerState next = new LexerState(this);
foreach (NFA.Edge e in state.alledges) {
if (!e.when.Accepts(ch)) continue;
next.AddNFAState(e.to);
}
if (LtmTrace)
Console.WriteLine("+ Changing state to {0}", next);
state = next;
}
List<int> uniqfates = new List<int>();
HashSet<int> usedfates = new HashSet<int>();
while (fate.Count != 0) {
int f = fate.Pop();
if (usedfates.Contains(f))
continue;
usedfates.Add(f);
if (LtmTrace)
Console.WriteLine("+ Useful fate: {0}", f);
uniqfates.Add(f);
}
return uniqfates.ToArray();
}
public static IP6[] RunProtoregex(IP6 cursor, string name) {
DynObject dc = (DynObject)cursor;
DynObject[] candidates = ResolveProtoregex(dc.klass, name);
LAD[] branches = new LAD[candidates.Length];
for (int i = 0; i < candidates.Length; i++)
branches[i] = ((SubInfo) candidates[i].slots["info"]).ltm;
Lexer l = new Lexer(dc, name, branches);
Cursor c = (Cursor)Kernel.UnboxAny(cursor);
int[] brnum = l.Run(c.backing, c.pos);
IP6[] ret = new IP6[brnum.Length];
for (int i = 0; i < brnum.Length; i++)
ret[i] = candidates[brnum[i]];
return ret;
}
public static DynObject[] ResolveProtoregex(DynMetaObject cursor_class,
string name) {
IP6 proto = cursor_class.Can(name);
List<DynObject> raword = new List<DynObject>();
foreach (DynMetaObject k in cursor_class.mro) {
if (proto != k.Can(name))
continue;
if (k.multiregex == null)
continue;
List<DynObject> locord;
if (k.multiregex.TryGetValue(name, out locord))
foreach (DynObject o in locord)
raword.Add(o);
}
HashSet<IP6> unshadowed = cursor_class.AllMethodsSet();
List<DynObject> useord = new List<DynObject>();
foreach (DynObject o in raword)
if (unshadowed.Contains(o))
useord.Add(o);
return useord.ToArray();
}
public static void SelfTest() {
Lexer l = new Lexer(null, "[for|forall]", new LAD[] {
new LADStr("for"),
new LADStr("forall"),
new LADPlus(new LADCC(new CCTerm[] { new CCTerm(CCTerm.AlNum) }))
});
l.Run("xforfoo--", 1);
l.Run("forallx", 0);
l.Run("forall", 0);
}
}