org.luaj.vm2.lib.StringLib Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2009-2011 Luaj.org. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm2.lib;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import org.luaj.vm2.LuaClosure;
import org.luaj.vm2.Buffer;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
import org.luaj.vm2.compiler.DumpState;
/**
* Subclass of {@link LibFunction} which implements the lua standard {@code string}
* library.
*
* Typically, this library is included as part of a call to either
* {@link org.luaj.vm2.lib.jse.JsePlatform#standardGlobals()} or {@link org.luaj.vm2.lib.jme.JmePlatform#standardGlobals()}
*
{@code
* Globals globals = JsePlatform.standardGlobals();
* System.out.println( globals.get("string").get("upper").call( LuaValue.valueOf("abcde") ) );
* }
*
* To instantiate and use it directly,
* link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as:
*
{@code
* Globals globals = new Globals();
* globals.load(new JseBaseLib());
* globals.load(new PackageLib());
* globals.load(new StringLib());
* System.out.println( globals.get("string").get("upper").call( LuaValue.valueOf("abcde") ) );
* }
*
* This is a direct port of the corresponding library in C.
* @see LibFunction
* @see org.luaj.vm2.lib.jse.JsePlatform
* @see org.luaj.vm2.lib.jme.JmePlatform
* @see Lua 5.2 String Lib Reference
*/
public class StringLib extends TwoArgFunction {
/** Construct a StringLib, which can be initialized by calling it with a
* modname string, and a global environment table as arguments using
* {@link #call(LuaValue, LuaValue)}. */
public StringLib() {
}
/** Perform one-time initialization on the library by creating a table
* containing the library functions, adding that table to the supplied environment,
* adding the table to package.loaded, and returning table as the return value.
* Creates a metatable that uses __INDEX to fall back on itself to support string
* method operations.
* If the shared strings metatable instance is null, will set the metatable as
* the global shared metatable for strings.
*
* All tables and metatables are read-write by default so if this will be used in
* a server environment, sandboxing should be used. In particular, the
* {@link LuaString#s_metatable} table should probably be made read-only.
* @param modname the module name supplied if this is loaded via 'require'.
* @param env the environment to load into, typically a Globals instance.
*/
public LuaValue call(LuaValue modname, LuaValue env) {
LuaTable string = new LuaTable();
string.set("byte", new byte_());
string.set("char", new char_());
string.set("dump", new dump());
string.set("find", new find());
string.set("format", new format());
string.set("gmatch", new gmatch());
string.set("gsub", new gsub());
string.set("len", new len());
string.set("lower", new lower());
string.set("match", new match());
string.set("rep", new rep());
string.set("reverse", new reverse());
string.set("sub", new sub());
string.set("upper", new upper());
LuaTable mt = LuaValue.tableOf(
new LuaValue[] { INDEX, string });
env.set("string", string);
env.get("package").get("loaded").set("string", string);
if (LuaString.s_metatable == null)
LuaString.s_metatable = mt;
return string;
}
/**
* string.byte (s [, i [, j]])
*
* Returns the internal numerical codes of the
* characters s[i], s[i+1], ..., s[j]. The default value for i is 1; the
* default value for j is i.
*
* Note that numerical codes are not necessarily portable across platforms.
*
* @param args the calling args
*/
static final class byte_ extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString s = args.checkstring(1);
int l = s.m_length;
int posi = posrelat( args.optint(2,1), l );
int pose = posrelat( args.optint(3,posi), l );
int n,i;
if (posi <= 0) posi = 1;
if (pose > l) pose = l;
if (posi > pose) return NONE; /* empty interval; return no values */
n = (int)(pose - posi + 1);
if (posi + n <= pose) /* overflow? */
error("string slice too long");
LuaValue[] v = new LuaValue[n];
for (i=0; i=256) argerror(a, "invalid value");
bytes[i] = (byte) c;
}
return LuaString.valueUsing( bytes );
}
}
/**
* string.dump (function)
*
* Returns a string containing a binary representation of the given function,
* so that a later loadstring on this string returns a copy of the function.
* function must be a Lua function without upvalues.
*
* TODO: port dumping code as optional add-on
*/
static final class dump extends OneArgFunction {
public LuaValue call(LuaValue arg) {
LuaValue f = arg.checkfunction();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
DumpState.dump( ((LuaClosure)f).p, baos, true );
return LuaString.valueUsing(baos.toByteArray());
} catch (IOException e) {
return error( e.getMessage() );
}
}
}
/**
* string.find (s, pattern [, init [, plain]])
*
* Looks for the first match of pattern in the string s.
* If it finds a match, then find returns the indices of s
* where this occurrence starts and ends; otherwise, it returns nil.
* A third, optional numerical argument init specifies where to start the search;
* its default value is 1 and may be negative. A value of true as a fourth,
* optional argument plain turns off the pattern matching facilities,
* so the function does a plain "find substring" operation,
* with no characters in pattern being considered "magic".
* Note that if plain is given, then init must be given as well.
*
* If the pattern has captures, then in a successful match the captured values
* are also returned, after the two indices.
*/
static final class find extends VarArgFunction {
public Varargs invoke(Varargs args) {
return str_find_aux( args, true );
}
}
/**
* string.format (formatstring, ...)
*
* Returns a formatted version of its variable number of arguments following
* the description given in its first argument (which must be a string).
* The format string follows the same rules as the printf family of standard C functions.
* The only differences are that the options/modifiers *, l, L, n, p, and h are not supported
* and that there is an extra option, q. The q option formats a string in a form suitable
* to be safely read back by the Lua interpreter: the string is written between double quotes,
* and all double quotes, newlines, embedded zeros, and backslashes in the string are correctly
* escaped when written. For instance, the call
* string.format('%q', 'a string with "quotes" and \n new line')
*
* will produce the string:
* "a string with \"quotes\" and \
* new line"
*
* The options c, d, E, e, f, g, G, i, o, u, X, and x all expect a number as argument,
* whereas q and s expect a string.
*
* This function does not accept string values containing embedded zeros,
* except as arguments to the q option.
*/
static final class format extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString fmt = args.checkstring( 1 );
final int n = fmt.length();
Buffer result = new Buffer(n);
int arg = 1;
int c;
for ( int i = 0; i < n; ) {
switch ( c = fmt.luaByte( i++ ) ) {
case '\n':
result.append( "\n" );
break;
default:
result.append( (byte) c );
break;
case L_ESC:
if ( i < n ) {
if ( ( c = fmt.luaByte( i ) ) == L_ESC ) {
++i;
result.append( (byte)L_ESC );
} else {
arg++;
FormatDesc fdsc = new FormatDesc(args, fmt, i );
i += fdsc.length;
switch ( fdsc.conversion ) {
case 'c':
fdsc.format( result, (byte)args.checkint( arg ) );
break;
case 'i':
case 'd':
fdsc.format( result, args.checkint( arg ) );
break;
case 'o':
case 'u':
case 'x':
case 'X':
fdsc.format( result, args.checklong( arg ) );
break;
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
fdsc.format( result, args.checkdouble( arg ) );
break;
case 'q':
addquoted( result, args.checkstring( arg ) );
break;
case 's': {
LuaString s = args.checkstring( arg );
if ( fdsc.precision == -1 && s.length() >= 100 ) {
result.append( s );
} else {
fdsc.format( result, s );
}
} break;
default:
error("invalid option '%"+(char)fdsc.conversion+"' to 'format'");
break;
}
}
}
}
}
return result.tostring();
}
}
private static void addquoted(Buffer buf, LuaString s) {
int c;
buf.append( (byte) '"' );
for ( int i = 0, n = s.length(); i < n; i++ ) {
switch ( c = s.luaByte( i ) ) {
case '"': case '\\': case '\n':
buf.append( (byte)'\\' );
buf.append( (byte)c );
break;
default:
if (c <= 0x1F || c == 0x7F) {
buf.append( (byte) '\\' );
if (i+1 == n || s.luaByte(i+1) < '0' || s.luaByte(i+1) > '9') {
buf.append(Integer.toString(c));
} else {
buf.append( (byte) '0' );
buf.append( (byte) (char) ('0' + c / 10) );
buf.append( (byte) (char) ('0' + c % 10) );
}
} else {
buf.append((byte) c);
}
break;
}
}
buf.append( (byte) '"' );
}
private static final String FLAGS = "-+ #0";
static class FormatDesc {
private boolean leftAdjust;
private boolean zeroPad;
private boolean explicitPlus;
private boolean space;
private boolean alternateForm;
private static final int MAX_FLAGS = 5;
private int width;
private int precision;
public final int conversion;
public final int length;
public FormatDesc(Varargs args, LuaString strfrmt, final int start) {
int p = start, n = strfrmt.length();
int c = 0;
boolean moreFlags = true;
while ( moreFlags ) {
switch ( c = ( (p < n) ? strfrmt.luaByte( p++ ) : 0 ) ) {
case '-': leftAdjust = true; break;
case '+': explicitPlus = true; break;
case ' ': space = true; break;
case '#': alternateForm = true; break;
case '0': zeroPad = true; break;
default: moreFlags = false; break;
}
}
if ( p - start > MAX_FLAGS )
error("invalid format (repeated flags)");
width = -1;
if ( Character.isDigit( (char)c ) ) {
width = c - '0';
c = ( (p < n) ? strfrmt.luaByte( p++ ) : 0 );
if ( Character.isDigit( (char) c ) ) {
width = width * 10 + (c - '0');
c = ( (p < n) ? strfrmt.luaByte( p++ ) : 0 );
}
}
precision = -1;
if ( c == '.' ) {
c = ( (p < n) ? strfrmt.luaByte( p++ ) : 0 );
if ( Character.isDigit( (char) c ) ) {
precision = c - '0';
c = ( (p < n) ? strfrmt.luaByte( p++ ) : 0 );
if ( Character.isDigit( (char) c ) ) {
precision = precision * 10 + (c - '0');
c = ( (p < n) ? strfrmt.luaByte( p++ ) : 0 );
}
}
}
if ( Character.isDigit( (char) c ) )
error("invalid format (width or precision too long)");
zeroPad &= !leftAdjust; // '-' overrides '0'
conversion = c;
length = p - start;
}
public void format(Buffer buf, byte c) {
// TODO: not clear that any of width, precision, or flags apply here.
buf.append(c);
}
public void format(Buffer buf, long number) {
String digits;
if ( number == 0 && precision == 0 ) {
digits = "";
} else {
int radix;
switch ( conversion ) {
case 'x':
case 'X':
radix = 16;
break;
case 'o':
radix = 8;
break;
default:
radix = 10;
break;
}
digits = Long.toString( number, radix );
if ( conversion == 'X' )
digits = digits.toUpperCase();
}
int minwidth = digits.length();
int ndigits = minwidth;
int nzeros;
if ( number < 0 ) {
ndigits--;
} else if ( explicitPlus || space ) {
minwidth++;
}
if ( precision > ndigits )
nzeros = precision - ndigits;
else if ( precision == -1 && zeroPad && width > minwidth )
nzeros = width - minwidth;
else
nzeros = 0;
minwidth += nzeros;
int nspaces = width > minwidth ? width - minwidth : 0;
if ( !leftAdjust )
pad( buf, ' ', nspaces );
if ( number < 0 ) {
if ( nzeros > 0 ) {
buf.append( (byte)'-' );
digits = digits.substring( 1 );
}
} else if ( explicitPlus ) {
buf.append( (byte)'+' );
} else if ( space ) {
buf.append( (byte)' ' );
}
if ( nzeros > 0 )
pad( buf, '0', nzeros );
buf.append( digits );
if ( leftAdjust )
pad( buf, ' ', nspaces );
}
public void format(Buffer buf, double x) {
// TODO
buf.append( String.valueOf( x ) );
}
public void format(Buffer buf, LuaString s) {
int nullindex = s.indexOf( (byte)'\0', 0 );
if ( nullindex != -1 )
s = s.substring( 0, nullindex );
buf.append(s);
}
public static final void pad(Buffer buf, char c, int n) {
byte b = (byte)c;
while ( n-- > 0 )
buf.append(b);
}
}
/**
* string.gmatch (s, pattern)
*
* Returns an iterator function that, each time it is called, returns the next captures
* from pattern over string s. If pattern specifies no captures, then the
* whole match is produced in each call.
*
* As an example, the following loop
* s = "hello world from Lua"
* for w in string.gmatch(s, "%a+") do
* print(w)
* end
*
* will iterate over all the words from string s, printing one per line.
* The next example collects all pairs key=value from the given string into a table:
* t = {}
* s = "from=world, to=Lua"
* for k, v in string.gmatch(s, "(%w+)=(%w+)") do
* t[k] = v
* end
*
* For this function, a '^' at the start of a pattern does not work as an anchor,
* as this would prevent the iteration.
*/
static final class gmatch extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString src = args.checkstring( 1 );
LuaString pat = args.checkstring( 2 );
return new GMatchAux(args, src, pat);
}
}
static class GMatchAux extends VarArgFunction {
private final int srclen;
private final MatchState ms;
private int soffset;
public GMatchAux(Varargs args, LuaString src, LuaString pat) {
this.srclen = src.length();
this.ms = new MatchState(args, src, pat);
this.soffset = 0;
}
public Varargs invoke(Varargs args) {
for ( ; soffset=0 ) {
int soff = soffset;
soffset = res;
return ms.push_captures( true, soff, res );
}
}
return NIL;
}
}
/**
* string.gsub (s, pattern, repl [, n])
* Returns a copy of s in which all (or the first n, if given) occurrences of the
* pattern have been replaced by a replacement string specified by repl, which
* may be a string, a table, or a function. gsub also returns, as its second value,
* the total number of matches that occurred.
*
* If repl is a string, then its value is used for replacement.
* The character % works as an escape character: any sequence in repl of the form %n,
* with n between 1 and 9, stands for the value of the n-th captured substring (see below).
* The sequence %0 stands for the whole match. The sequence %% stands for a single %.
*
* If repl is a table, then the table is queried for every match, using the first capture
* as the key; if the pattern specifies no captures, then the whole match is used as the key.
*
* If repl is a function, then this function is called every time a match occurs,
* with all captured substrings passed as arguments, in order; if the pattern specifies
* no captures, then the whole match is passed as a sole argument.
*
* If the value returned by the table query or by the function call is a string or a number,
* then it is used as the replacement string; otherwise, if it is false or nil,
* then there is no replacement (that is, the original match is kept in the string).
*
* Here are some examples:
* x = string.gsub("hello world", "(%w+)", "%1 %1")
* --> x="hello hello world world"
*
* x = string.gsub("hello world", "%w+", "%0 %0", 1)
* --> x="hello hello world"
*
* x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
* --> x="world hello Lua from"
*
* x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
* --> x="home = /home/roberto, user = roberto"
*
* x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
* return loadstring(s)()
* end)
* --> x="4+5 = 9"
*
* local t = {name="lua", version="5.1"}
* x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t)
* --> x="lua-5.1.tar.gz"
*/
static final class gsub extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString src = args.checkstring( 1 );
final int srclen = src.length();
LuaString p = args.checkstring( 2 );
LuaValue repl = args.arg( 3 );
int max_s = args.optint( 4, srclen + 1 );
final boolean anchor = p.length() > 0 && p.charAt( 0 ) == '^';
Buffer lbuf = new Buffer( srclen );
MatchState ms = new MatchState( args, src, p );
int soffset = 0;
int n = 0;
while ( n < max_s ) {
ms.reset();
int res = ms.match( soffset, anchor ? 1 : 0 );
if ( res != -1 ) {
n++;
ms.add_value( lbuf, soffset, res, repl );
}
if ( res != -1 && res > soffset )
soffset = res;
else if ( soffset < srclen )
lbuf.append( (byte) src.luaByte( soffset++ ) );
else
break;
if ( anchor )
break;
}
lbuf.append( src.substring( soffset, srclen ) );
return varargsOf(lbuf.tostring(), valueOf(n));
}
}
/**
* string.len (s)
*
* Receives a string and returns its length. The empty string "" has length 0.
* Embedded zeros are counted, so "a\000bc\000" has length 5.
*/
static final class len extends OneArgFunction {
public LuaValue call(LuaValue arg) {
return arg.checkstring().len();
}
}
/**
* string.lower (s)
*
* Receives a string and returns a copy of this string with all uppercase letters
* changed to lowercase. All other characters are left unchanged.
* The definition of what an uppercase letter is depends on the current locale.
*/
static final class lower extends OneArgFunction {
public LuaValue call(LuaValue arg) {
return valueOf( arg.checkjstring().toLowerCase() );
}
}
/**
* string.match (s, pattern [, init])
*
* Looks for the first match of pattern in the string s. If it finds one,
* then match returns the captures from the pattern; otherwise it returns
* nil. If pattern specifies no captures, then the whole match is returned.
* A third, optional numerical argument init specifies where to start the
* search; its default value is 1 and may be negative.
*/
static final class match extends VarArgFunction {
public Varargs invoke(Varargs args) {
return str_find_aux( args, false );
}
}
/**
* string.rep (s, n)
*
* Returns a string that is the concatenation of n copies of the string s.
*/
static final class rep extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString s = args.checkstring( 1 );
int n = args.checkint( 2 );
final byte[] bytes = new byte[ s.length() * n ];
int len = s.length();
for ( int offset = 0; offset < bytes.length; offset += len ) {
s.copyInto( 0, bytes, offset, len );
}
return LuaString.valueUsing( bytes );
}
}
/**
* string.reverse (s)
*
* Returns a string that is the string s reversed.
*/
static final class reverse extends OneArgFunction {
public LuaValue call(LuaValue arg) {
LuaString s = arg.checkstring();
int n = s.length();
byte[] b = new byte[n];
for ( int i=0, j=n-1; i l )
end = l;
if ( start <= end ) {
return s.substring( start-1 , end );
} else {
return EMPTYSTRING;
}
}
}
/**
* string.upper (s)
*
* Receives a string and returns a copy of this string with all lowercase letters
* changed to uppercase. All other characters are left unchanged.
* The definition of what a lowercase letter is depends on the current locale.
*/
static final class upper extends OneArgFunction {
public LuaValue call(LuaValue arg) {
return valueOf(arg.checkjstring().toUpperCase());
}
}
/**
* This utility method implements both string.find and string.match.
*/
static Varargs str_find_aux( Varargs args, boolean find ) {
LuaString s = args.checkstring( 1 );
LuaString pat = args.checkstring( 2 );
int init = args.optint( 3, 1 );
if ( init > 0 ) {
init = Math.min( init - 1, s.length() );
} else if ( init < 0 ) {
init = Math.max( 0, s.length() + init );
}
boolean fastMatch = find && ( args.arg(4).toboolean() || pat.indexOfAny( SPECIALS ) == -1 );
if ( fastMatch ) {
int result = s.indexOf( pat, init );
if ( result != -1 ) {
return varargsOf( valueOf(result+1), valueOf(result+pat.length()) );
}
} else {
MatchState ms = new MatchState( args, s, pat );
boolean anchor = false;
int poff = 0;
if ( pat.luaByte( 0 ) == '^' ) {
anchor = true;
poff = 1;
}
int soff = init;
do {
int res;
ms.reset();
if ( ( res = ms.match( soff, poff ) ) != -1 ) {
if ( find ) {
return varargsOf( valueOf(soff+1), valueOf(res), ms.push_captures( false, soff, res ));
} else {
return ms.push_captures( true, soff, res );
}
}
} while ( soff++ < s.length() && !anchor );
}
return NIL;
}
private static int posrelat( int pos, int len ) {
return ( pos >= 0 ) ? pos : len + pos + 1;
}
// Pattern matching implementation
private static final int L_ESC = '%';
private static final LuaString SPECIALS = valueOf("^$*+?.([%-");
private static final int MAX_CAPTURES = 32;
private static final int CAP_UNFINISHED = -1;
private static final int CAP_POSITION = -2;
private static final byte MASK_ALPHA = 0x01;
private static final byte MASK_LOWERCASE = 0x02;
private static final byte MASK_UPPERCASE = 0x04;
private static final byte MASK_DIGIT = 0x08;
private static final byte MASK_PUNCT = 0x10;
private static final byte MASK_SPACE = 0x20;
private static final byte MASK_CONTROL = 0x40;
private static final byte MASK_HEXDIGIT = (byte)0x80;
private static final byte[] CHAR_TABLE;
static {
CHAR_TABLE = new byte[256];
for ( int i = 0; i < 256; ++i ) {
final char c = (char) i;
CHAR_TABLE[i] = (byte)( ( Character.isDigit( c ) ? MASK_DIGIT : 0 ) |
( Character.isLowerCase( c ) ? MASK_LOWERCASE : 0 ) |
( Character.isUpperCase( c ) ? MASK_UPPERCASE : 0 ) |
( ( c < ' ' || c == 0x7F ) ? MASK_CONTROL : 0 ) );
if ( ( c >= 'a' && c <= 'f' ) || ( c >= 'A' && c <= 'F' ) || ( c >= '0' && c <= '9' ) ) {
CHAR_TABLE[i] |= MASK_HEXDIGIT;
}
if ( ( c >= '!' && c <= '/' ) || ( c >= ':' && c <= '@' ) ) {
CHAR_TABLE[i] |= MASK_PUNCT;
}
if ( ( CHAR_TABLE[i] & ( MASK_LOWERCASE | MASK_UPPERCASE ) ) != 0 ) {
CHAR_TABLE[i] |= MASK_ALPHA;
}
}
CHAR_TABLE[' '] = MASK_SPACE;
CHAR_TABLE['\r'] |= MASK_SPACE;
CHAR_TABLE['\n'] |= MASK_SPACE;
CHAR_TABLE['\t'] |= MASK_SPACE;
CHAR_TABLE[0x0C /* '\v' */ ] |= MASK_SPACE;
CHAR_TABLE['\f'] |= MASK_SPACE;
};
static class MatchState {
final LuaString s;
final LuaString p;
final Varargs args;
int level;
int[] cinit;
int[] clen;
MatchState( Varargs args, LuaString s, LuaString pattern ) {
this.s = s;
this.p = pattern;
this.args = args;
this.level = 0;
this.cinit = new int[ MAX_CAPTURES ];
this.clen = new int[ MAX_CAPTURES ];
}
void reset() {
level = 0;
}
private void add_s( Buffer lbuf, LuaString news, int soff, int e ) {
int l = news.length();
for ( int i = 0; i < l; ++i ) {
byte b = (byte) news.luaByte( i );
if ( b != L_ESC ) {
lbuf.append( (byte) b );
} else {
++i; // skip ESC
b = (byte) news.luaByte( i );
if ( !Character.isDigit( (char) b ) ) {
lbuf.append( b );
} else if ( b == '0' ) {
lbuf.append( s.substring( soff, e ) );
} else {
lbuf.append( push_onecapture( b - '1', soff, e ).strvalue() );
}
}
}
}
public void add_value( Buffer lbuf, int soffset, int end, LuaValue repl ) {
switch ( repl.type() ) {
case LuaValue.TSTRING:
case LuaValue.TNUMBER:
add_s( lbuf, repl.strvalue(), soffset, end );
return;
case LuaValue.TFUNCTION:
repl = repl.invoke( push_captures( true, soffset, end ) ).arg1();
break;
case LuaValue.TTABLE:
// Need to call push_onecapture here for the error checking
repl = repl.get( push_onecapture( 0, soffset, end ) );
break;
default:
error( "bad argument: string/function/table expected" );
return;
}
if ( !repl.toboolean() ) {
repl = s.substring( soffset, end );
} else if ( ! repl.isstring() ) {
error( "invalid replacement value (a "+repl.typename()+")" );
}
lbuf.append( repl.strvalue() );
}
Varargs push_captures( boolean wholeMatch, int soff, int end ) {
int nlevels = ( this.level == 0 && wholeMatch ) ? 1 : this.level;
switch ( nlevels ) {
case 0: return NONE;
case 1: return push_onecapture( 0, soff, end );
}
LuaValue[] v = new LuaValue[nlevels];
for ( int i = 0; i < nlevels; ++i )
v[i] = push_onecapture( i, soff, end );
return varargsOf(v);
}
private LuaValue push_onecapture( int i, int soff, int end ) {
if ( i >= this.level ) {
if ( i == 0 ) {
return s.substring( soff, end );
} else {
return error( "invalid capture index" );
}
} else {
int l = clen[i];
if ( l == CAP_UNFINISHED ) {
return error( "unfinished capture" );
}
if ( l == CAP_POSITION ) {
return valueOf( cinit[i] + 1 );
} else {
int begin = cinit[i];
return s.substring( begin, begin + l );
}
}
}
private int check_capture( int l ) {
l -= '1';
if ( l < 0 || l >= level || this.clen[l] == CAP_UNFINISHED ) {
error("invalid capture index");
}
return l;
}
private int capture_to_close() {
int level = this.level;
for ( level--; level >= 0; level-- )
if ( clen[level] == CAP_UNFINISHED )
return level;
error("invalid pattern capture");
return 0;
}
int classend( int poffset ) {
switch ( p.luaByte( poffset++ ) ) {
case L_ESC:
if ( poffset == p.length() ) {
error( "malformed pattern (ends with %)" );
}
return poffset + 1;
case '[':
if ( p.luaByte( poffset ) == '^' ) poffset++;
do {
if ( poffset == p.length() ) {
error( "malformed pattern (missing ])" );
}
if ( p.luaByte( poffset++ ) == L_ESC && poffset != p.length() )
poffset++;
} while ( p.luaByte( poffset ) != ']' );
return poffset + 1;
default:
return poffset;
}
}
static boolean match_class( int c, int cl ) {
final char lcl = Character.toLowerCase( (char) cl );
int cdata = CHAR_TABLE[c];
boolean res;
switch ( lcl ) {
case 'a': res = ( cdata & MASK_ALPHA ) != 0; break;
case 'd': res = ( cdata & MASK_DIGIT ) != 0; break;
case 'l': res = ( cdata & MASK_LOWERCASE ) != 0; break;
case 'u': res = ( cdata & MASK_UPPERCASE ) != 0; break;
case 'c': res = ( cdata & MASK_CONTROL ) != 0; break;
case 'p': res = ( cdata & MASK_PUNCT ) != 0; break;
case 's': res = ( cdata & MASK_SPACE ) != 0; break;
case 'w': res = ( cdata & ( MASK_ALPHA | MASK_DIGIT ) ) != 0; break;
case 'x': res = ( cdata & MASK_HEXDIGIT ) != 0; break;
case 'z': res = ( c == 0 ); break;
default: return cl == c;
}
return ( lcl == cl ) ? res : !res;
}
boolean matchbracketclass( int c, int poff, int ec ) {
boolean sig = true;
if ( p.luaByte( poff + 1 ) == '^' ) {
sig = false;
poff++;
}
while ( ++poff < ec ) {
if ( p.luaByte( poff ) == L_ESC ) {
poff++;
if ( match_class( c, p.luaByte( poff ) ) )
return sig;
}
else if ( ( p.luaByte( poff + 1 ) == '-' ) && ( poff + 2 < ec ) ) {
poff += 2;
if ( p.luaByte( poff - 2 ) <= c && c <= p.luaByte( poff ) )
return sig;
}
else if ( p.luaByte( poff ) == c ) return sig;
}
return !sig;
}
boolean singlematch( int c, int poff, int ep ) {
switch ( p.luaByte( poff ) ) {
case '.': return true;
case L_ESC: return match_class( c, p.luaByte( poff + 1 ) );
case '[': return matchbracketclass( c, poff, ep - 1 );
default: return p.luaByte( poff ) == c;
}
}
/**
* Perform pattern matching. If there is a match, returns offset into s
* where match ends, otherwise returns -1.
*/
int match( int soffset, int poffset ) {
while ( true ) {
// Check if we are at the end of the pattern -
// equivalent to the '\0' case in the C version, but our pattern
// string is not NUL-terminated.
if ( poffset == p.length() )
return soffset;
switch ( p.luaByte( poffset ) ) {
case '(':
if ( ++poffset < p.length() && p.luaByte( poffset ) == ')' )
return start_capture( soffset, poffset + 1, CAP_POSITION );
else
return start_capture( soffset, poffset, CAP_UNFINISHED );
case ')':
return end_capture( soffset, poffset + 1 );
case L_ESC:
if ( poffset + 1 == p.length() )
error("malformed pattern (ends with '%')");
switch ( p.luaByte( poffset + 1 ) ) {
case 'b':
soffset = matchbalance( soffset, poffset + 2 );
if ( soffset == -1 ) return -1;
poffset += 4;
continue;
case 'f': {
poffset += 2;
if ( p.luaByte( poffset ) != '[' ) {
error("Missing [ after %f in pattern");
}
int ep = classend( poffset );
int previous = ( soffset == 0 ) ? -1 : s.luaByte( soffset - 1 );
if ( matchbracketclass( previous, poffset, ep - 1 ) ||
matchbracketclass( s.luaByte( soffset ), poffset, ep - 1 ) )
return -1;
poffset = ep;
continue;
}
default: {
int c = p.luaByte( poffset + 1 );
if ( Character.isDigit( (char) c ) ) {
soffset = match_capture( soffset, c );
if ( soffset == -1 )
return -1;
return match( soffset, poffset + 2 );
}
}
}
case '$':
if ( poffset + 1 == p.length() )
return ( soffset == s.length() ) ? soffset : -1;
}
int ep = classend( poffset );
boolean m = soffset < s.length() && singlematch( s.luaByte( soffset ), poffset, ep );
int pc = ( ep < p.length() ) ? p.luaByte( ep ) : '\0';
switch ( pc ) {
case '?':
int res;
if ( m && ( ( res = match( soffset + 1, ep + 1 ) ) != -1 ) )
return res;
poffset = ep + 1;
continue;
case '*':
return max_expand( soffset, poffset, ep );
case '+':
return ( m ? max_expand( soffset + 1, poffset, ep ) : -1 );
case '-':
return min_expand( soffset, poffset, ep );
default:
if ( !m )
return -1;
soffset++;
poffset = ep;
continue;
}
}
}
int max_expand( int soff, int poff, int ep ) {
int i = 0;
while ( soff + i < s.length() &&
singlematch( s.luaByte( soff + i ), poff, ep ) )
i++;
while ( i >= 0 ) {
int res = match( soff + i, ep + 1 );
if ( res != -1 )
return res;
i--;
}
return -1;
}
int min_expand( int soff, int poff, int ep ) {
for ( ;; ) {
int res = match( soff, ep + 1 );
if ( res != -1 )
return res;
else if ( soff < s.length() && singlematch( s.luaByte( soff ), poff, ep ) )
soff++;
else return -1;
}
}
int start_capture( int soff, int poff, int what ) {
int res;
int level = this.level;
if ( level >= MAX_CAPTURES ) {
error( "too many captures" );
}
cinit[ level ] = soff;
clen[ level ] = what;
this.level = level + 1;
if ( ( res = match( soff, poff ) ) == -1 )
this.level--;
return res;
}
int end_capture( int soff, int poff ) {
int l = capture_to_close();
int res;
clen[l] = soff - cinit[l];
if ( ( res = match( soff, poff ) ) == -1 )
clen[l] = CAP_UNFINISHED;
return res;
}
int match_capture( int soff, int l ) {
l = check_capture( l );
int len = clen[ l ];
if ( ( s.length() - soff ) >= len &&
LuaString.equals( s, cinit[l], s, soff, len ) )
return soff + len;
else
return -1;
}
int matchbalance( int soff, int poff ) {
final int plen = p.length();
if ( poff == plen || poff + 1 == plen ) {
error( "unbalanced pattern" );
}
final int slen = s.length();
if ( soff >= slen )
return -1;
final int b = p.luaByte( poff );
if ( s.luaByte( soff ) != b )
return -1;
final int e = p.luaByte( poff + 1 );
int cont = 1;
while ( ++soff < slen ) {
if ( s.luaByte( soff ) == e ) {
if ( --cont == 0 ) return soff + 1;
}
else if ( s.luaByte( soff ) == b ) cont++;
}
return -1;
}
}
}