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Port regex optimizer
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@sorear
sorear committed Jun 4, 2012
1 parent fb31c9b commit 154e541
Showing 1 changed file with 162 additions and 7 deletions.
169 changes: 162 additions & 7 deletions lib/RxOp.cs
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Expand Up @@ -40,6 +40,49 @@ abstract class RxOp {

// placeholders...
protected void AddMyName(params object[] args) { throw new NotImplementedException(); }

public static object[] optimize_lad(object[] lad) {
if ((string)lad[0] != "Sequence")
return lad;
var zyg = (object[][])lad[1];
var fzyg = new List<object[]>();
foreach(object[] z in zyg) {
var oz = optimize_lad(z);
if ((string)oz[0] == "Sequence") {
foreach (var zz in (object[][])oz[1])
fzyg.Add(zz);
} else if ((string)oz[0] == "Null") {
} else {
fzyg.Add(oz);
}
}
var ozyg = new List<object[]>();
foreach (var fz in fzyg) {
if ((string)fz[0] == "None") return fz;
if ((string)fz[0] == "Imp") {
ozyg.Add(fz);
break;
} else if (ozyg.Count != 0 && (string)ozyg[ozyg.Count - 1][0] == "Str" && (string)fz[0] == "Str") {
ozyg[ozyg.Count-1] = new [] { "Str", ((string)ozyg[ozyg.Count-1][1]) + ((string)fz[1]) };
} else {
ozyg.Add(fz);
}
}
if (ozyg.Count == 0) {
return new object[] { "Null" };
} else if (ozyg.Count == 1) {
return ozyg[0];
} else {
return new object[] { "Sequence", ozyg.ToArray() };
}
}

public virtual bool mayback() { return true; }
public virtual RxOp rxsimp(bool cut) {
for (int i = 0; i < zyg.Length; i++)
zyg[i] = zyg[i].rxsimp(false);
return this;
}
}

abstract class Capturing : RxOp {
Expand Down Expand Up @@ -94,10 +137,11 @@ class Sym : Capturing {
return endsym != null ? new object[] { "Sequence",
new [] { m, new [] { "Method", endsym } } } : m;
}
public override bool mayback() { return false; }
}

class String : RxOp {
string text;
internal string text;
bool igcase;

public String(string text, bool igcase=false) {
Expand All @@ -119,6 +163,7 @@ class String : RxOp {
public override object[] lad() {
return new [] { igcase ? "StrNoCase": "Str", text };
}
public override bool mayback() { return false; }
}

class VarString : RxOp {
Expand All @@ -133,6 +178,7 @@ class VarString : RxOp {
acc.Add(CgOp.rxbprim("Exact", CgOp.obj_getstr(ops.cgop(body))));
}

public override bool mayback() { return false; }
public override object[] lad() { return new[] { "Imp" }; }
}

Expand All @@ -149,6 +195,13 @@ class Quantifier : RxOp {
this.opsep = opsep;
}

public override RxOp rxsimp(bool cut) {
base.rxsimp(cut);
if (cut && zyg.Length == 1 && zyg[0] is CClassElem)
return new QuantCClass(((CClassElem)zyg[0]).cc, min, max);
return this;
}

public override void VisitOps(Func<Op.Op,Op.Op> post) {
if (closure != null) closure = closure.VisitOps(post);
}
Expand Down Expand Up @@ -236,7 +289,7 @@ class Quantifier : RxOp {
}

class Sequence : RxOp {
public Sequence(RxOp[] z) : base(z) { }
public Sequence(RxOp[] z = null) : base(z ?? new RxOp[0]) { }

public override void code(SubInfo body, List<object> acc) {
foreach (RxOp z in zyg) z.code(body, acc);
Expand All @@ -252,6 +305,24 @@ class Sequence : RxOp {
ar[i] = zyg[i].lad();
return new object[] { "Sequence", ar };
}

public override RxOp rxsimp(bool cut) {
var kids = new List<RxOp>();
for (int i = 0; i < zyg.Length; i++) {
var k = zyg[i].rxsimp(cut && (i == zyg.Length - 1));
if (k is Sequence) {
foreach (var kz in k.zyg) kids.Add(kz);
} else {
kids.Add(k);
}
}
return (kids.Count == 1) ? kids[0] : new Sequence(kids.ToArray());
}

public override bool mayback() {
foreach (RxOp z in zyg) if (z.mayback()) return true;
return false;
}
}

class Conj : RxOp {
Expand Down Expand Up @@ -324,6 +395,7 @@ class ConfineLang : RxOp {
acc.Add(CgOp.popcut());
}
public override object[] lad() { return zyg[0].lad(); }
public override bool mayback() { return zyg[0].mayback(); }
}

class Cut : RxOp {
Expand All @@ -338,15 +410,22 @@ class Cut : RxOp {
to.Add(CgOp.rxcommitgroup(CgOp.str("CUTGRP")));
to.Add(CgOp.popcut());
}

public override RxOp rxsimp(bool cut) {
var kid = zyg[0].rxsimp(true);
return kid.mayback() ? new Cut(kid) : kid;
}
public override bool mayback() { return false; }
}

class BeforeString : RxOp {
string str;
public BeforeString(string s) { str = s; }
internal string text;
public BeforeString(string s) { text = s; }

public override void code(SubInfo sub, List<object> to) {
to.Add(CgOp.rxbprim("BeforeStr", CgOp.@bool(0), CgOp.str(str)));
to.Add(CgOp.rxbprim("BeforeStr", CgOp.@bool(0), CgOp.str(text)));
}
public override bool mayback() { return false; }
}

class ZeroWidthCCs : RxOp {
Expand All @@ -361,15 +440,18 @@ class ZeroWidthCCs : RxOp {
to.Add(CgOp.rxbprim(after ? "AfterCCs" : "BeforeCCs",
CgOp.@bool(neg?1:0), CgOp.@const(ccs)));
}
public ZeroWidthCCs zerowidthify(bool n) { return new ZeroWidthCCs(ccs, after, !neg); }
public override bool mayback() { return false; }
}

class NotBeforeString : RxOp {
string str;
internal string str;
public NotBeforeString(string s) { str = s; }

public override void code(SubInfo body, List<object> to) {
to.Add(CgOp.rxbprim("BeforeStr", CgOp.@bool(1), CgOp.str(str)));
}
public override bool mayback() { return false; }
}

class ZeroWidth : RxOp {
Expand All @@ -380,6 +462,7 @@ class ZeroWidth : RxOp {
public override void code(SubInfo body, List<object> to) {
to.Add(CgOp.rxbprim("ZeroWidth", CgOp.@int(type)));
}
public override bool mayback() { return false; }
}

class NotBefore : RxOp {
Expand All @@ -396,6 +479,24 @@ class NotBefore : RxOp {
to.Add(CgOp.label(pass));
to.Add(CgOp.popcut());
}

public override bool mayback() { return false; }
public override RxOp rxsimp(bool c) {
var z = zyg[0].rxsimp(true);
if (z is BeforeString)
return new NotBeforeString(((BeforeString)z).text);
if (z is Before)
return new NotBefore(z.zyg[0]);
if (z is String)
return new NotBeforeString(((String)z).text);
if (z is Subrule)
return ((Subrule)z).zerowidthify(true);
if (z is ZeroWidthCCs)
return ((ZeroWidthCCs)z).zerowidthify(true);
if (z is CClassElem)
return new ZeroWidthCCs(new [] { ((CClassElem)z).cc }, false, true);
return new NotBefore(z);
}
}

class Before : RxOp {
Expand All @@ -406,6 +507,21 @@ class Before : RxOp {
public override void code(SubInfo body, List<object> to) {
(new NotBefore(new NotBefore(zyg[0]))).code(body,to);
}
public override bool mayback() { return false; }
// it's not unusual to write <!before> and <?before>
public override RxOp rxsimp(bool c) {
var z = zyg[0].rxsimp(true);
if (z is BeforeString || z is ZeroWidthCCs || z is ZeroWidth ||
z is Before || z is NotBefore)
return z;
if (z is String)
return new BeforeString(((String)z).text);
if (z is Subrule)
return ((Subrule)z).zerowidthify(false);
if (z is CClassElem)
return new ZeroWidthCCs(new [] { ((CClassElem)z).cc }, false, false);
return new Before(z);
}
}

class Tilde : RxOp {
Expand Down Expand Up @@ -447,6 +563,11 @@ class Subrule : Capturing {
}
public Subrule(string method, bool selfcut) { this.method = method; this.selfcut = selfcut; }

public override RxOp rxsimp(bool cut) {
return cut ? new Subrule(method,regex,ltm,true,zerowidth,negative) : this;
}
public override bool mayback() { return !selfcut; }

public override void VisitOps(Func<Op.Op,Op.Op> post) {
if (regex != null) regex = regex.VisitOps(post);
}
Expand All @@ -457,6 +578,10 @@ class Subrule : Capturing {
return n;
}

internal RxOp zerowidthify(bool negate) {
return new Subrule(method,regex,ltm,selfcut,true,negate?!negative:negative);
}

public override void code(SubInfo body, List<object> to) {
var callf = regex != null ? regex.cgop(body) :
CgOp.methodcall(CgOp.rxcall("MakeCursorV"), method);
Expand Down Expand Up @@ -487,27 +612,35 @@ class Sigspace : RxOp {
public override void code(SubInfo body, List<object> to){
(new Subrule("ws", selfcut)).code(body, to);
}

public override RxOp rxsimp(bool cut) {
return cut ? new Sigspace(true) : this;
}
public override bool mayback() { return !selfcut; }
}

class CutLTM : RxOp {
public override object[] lad() { return new [] { "Imp" }; } // special
public override void code(SubInfo s, List<object> to) {
to.Add(CgOp.rxcall("CommitGroup", CgOp.str("LTM")));
}
public override bool mayback() { return false; }
}

class CutRule : RxOp {
public override object[] lad() { return new [] { "Null" }; }
public override void code(SubInfo s, List<object> to) {
to.Add(CgOp.rxcall("CommitRule"));
}
public override bool mayback() { return false; }
}

class CutBrack : RxOp {
public override object[] lad() { return new [] { "Null" }; }
public override void code(SubInfo s, List<object> to) {
to.Add(CgOp.rxcall("CommitGroup", CgOp.str("BRACK")));
}
public override bool mayback() { return false; }
}

class SetLang : RxOp {
Expand All @@ -521,6 +654,7 @@ class SetLang : RxOp {
to.Add(CgOp.rxsetclass(CgOp.obj_llhow(CgOp.fetch(expr.cgop(body)))));
}
public override object[] lad() { return new [] { "Imp" }; }
public override bool mayback() { return false; }
}

class Alt : AltBase {
Expand Down Expand Up @@ -548,6 +682,18 @@ class Alt : AltBase {
for (int i = 0; i < z.Length; i++) z[i] = zyg[i].lad();
return new object[] { "Any", z };
}

public override RxOp rxsimp(bool cut) {
var lads = new object[zyg.Length][];
var kids = new RxOp[zyg.Length];
for (int i = 0; i < zyg.Length; i++) {
lads[i] = optimize_lad(zyg[i].lad());
kids[i] = zyg[i].rxsimp(cut);
}
var n = new Alt(kids, dba);
n.optimized_lads = lads;
return n;
}
}

class CheckBlock : RxOp {
Expand All @@ -562,6 +708,7 @@ class CheckBlock : RxOp {
to.Add(CgOp.N(negate ? "cgoto" : "ncgoto", "backtrack",
CgOp.obj_getbool(block.cgop(body))));
}
public override bool mayback() { return false; }
}

class SaveValue : RxOp {
Expand All @@ -578,6 +725,7 @@ class SaveValue : RxOp {
public override void code(SubInfo body, List<object> to) {
to.Add(CgOp.rxpushcapture(block.cgop(body), new [] { capid }));
}
public override bool mayback() { return false; }
}

class VoidBlock : RxOp {
Expand All @@ -586,6 +734,7 @@ class VoidBlock : RxOp {
public override void VisitOps(Func<Op.Op,Op.Op> post) {
block = block.VisitOps(post);
}
public override bool mayback() { return false; }
public override object[] lad() { return new [] { "Imp" }; }
public override void code(SubInfo body, List<object> to) {
to.Add(CgOp.sink(block.cgop(body)));
Expand All @@ -600,6 +749,8 @@ class Statement : RxOp {
// to the RegexBody node.
public override void code(SubInfo body, List<object> to) {}
public override object[] lad() { return new [] { "Null" }; }
public override RxOp rxsimp(bool cut) { return new Sequence(); }
public override bool mayback() { return false; }
}

class ProtoRedis : Capturing {
Expand All @@ -625,6 +776,7 @@ class Any : RxOp {
to.Add(CgOp.rxbprim("AnyChar"));
}
public override object[] lad() { return new [] { "Dot" }; }
public override bool mayback() { return false; }
}

// generated by optimizer so needs no lad; always greedy
Expand All @@ -637,10 +789,11 @@ class QuantCClass : RxOp {
to.Add(CgOp.rxbprim("ScanCClass", CgOp.@int(min), CgOp.@int(max),
CgOp.@const(cc)));
}
public override bool mayback() { return false; }
}

class CClassElem : RxOp {
CClass cc;
internal CClass cc;
public CClassElem(CClass c) { cc = c; }
public override void code(SubInfo body, List<object> to) {
to.Add(CgOp.rxbprim("CClass", CgOp.@const(cc)));
Expand All @@ -651,13 +804,15 @@ class CClassElem : RxOp {
Array.Copy(cc.terms,0,terms,1,terms.Length-1);
return terms;
}
public override bool mayback() { return false; }
}

class None : RxOp {
public override void code(SubInfo s,List<object> to) {
to.Add(CgOp.@goto("backtrack"));
}
public override object[] lad() { return new [] { "None" }; }
public override bool mayback() { return false; }
}

class Newline : RxOp {
Expand Down

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