gecko-dev/tools/dreftool/CScanner.cpp
1999-08-04 19:44:15 +00:00

236 lines
4.3 KiB
C++

/*
* Copyright (C) 1998 Rick Gessner. All Rights Reserved.
*/
#include "CScanner.h"
const int kBufsize=1024;
/**
* Use this constructor if you want i/o to be stream based.
*
* @update gess 5/12/98
* @param aStream --
* @param assumeOwnership --
* @param aFilename --
* @return
*/
CScanner::CScanner(istream& aStream) : mBuffer(""), mFileStream(aStream) {
mIncremental=true;
mOffset=0;
mTotalRead=0;
}
/**
* default destructor
*
* @update gess 3/25/98
* @param
* @return
*/
CScanner::~CScanner() {
}
/**
* Grab data from underlying stream.
*
* @update gess4/3/98
* @return error code
*/
int CScanner::fillBuffer(void) {
int anError=kNoError;
mBuffer="";
if(!mFileStream) {
//This is DEBUG code!!!!!! XXX DEBUG XXX
//If you're here, it means someone tried to load a
//non-existent document. So as a favor, we emit a
//little bit of HTML explaining the error.
anError=(mIncremental) ? kInterrupted : kEOF;
}
else {
int numread=0;
char buf[kBufsize+1];
buf[kBufsize]=0;
if(mFileStream) {
mFileStream.read(buf,kBufsize);
numread=mFileStream.gcount();
buf[numread]=0;
}
mOffset=0;
if((0<numread) && (0==anError))
mBuffer=buf;
mTotalRead+=mBuffer.Length();
}
return anError;
}
/**
* determine if the scanner has reached EOF
*
* @update gess 5/12/98
* @param
* @return 0=!eof 1=eof kInterrupted=interrupted
*/
int CScanner::endOfFile() {
int theError=kNoError;
if(mOffset>=mBuffer.Length()) {
theError=fillBuffer();
}
if(kNoError==theError) {
if (0==mBuffer.Length()) {
return kEOF;
}
}
return theError;
}
/**
* retrieve next char from scanners internal input stream
*
* @update gess 3/25/98
* @param
* @return error code reflecting read status
*/
int CScanner::getChar(PRUnichar& aChar) {
int result=kNoError;
if(mOffset>=mBuffer.Length())
result=endOfFile();
if(kNoError == result) {
aChar=mBuffer.CharAt(mOffset++);
}
return result;
}
/**
* peek ahead to consume next char from scanner's internal
* input buffer
*
* @update gess 3/25/98
* @param
* @return
*/
int CScanner::peek(PRUnichar& aChar) {
int result=kNoError;
if(mOffset>=mBuffer.Length())
result=endOfFile();
if(kNoError == result) {
aChar=mBuffer.CharAt(mOffset);
}
return result;
}
/**
* Push the given char back onto the scanner
*
* @update gess 3/25/98
* @param
* @return error code
*/
int CScanner::push(PRUnichar aChar) {
if(mOffset>0)
mOffset--;
else {
mBuffer.Insert(aChar,0);
}
return kNoError;
}
/**
* Consume chars as long as they are <i>in</i> the
* given validSet of input chars.
*
* @update gess 3/25/98
* @param
* @return error code
*/
int CScanner::readWhile(nsCString& aString,nsCString& aValidSet,bool addTerminal){
PRUnichar theChar=0;
int result=kNoError;
while(kNoError==result) {
result=getChar(theChar);
if(kNoError==result) {
int pos=aValidSet.Find(theChar);
if(kNotFound==pos) {
if(addTerminal)
aString+=theChar;
else push(theChar);
break;
}
else aString+=theChar;
}
}
return result;
}
/**
* Consume characters until you find one contained in given
* input set.
*
* @update gess 3/25/98
* @param
* @return error code
*/
int CScanner::readUntil(nsCString& aString,nsCString& aTerminalSet,bool addTerminal){
PRUnichar theChar=0;
int result=kNoError;
while(kNoError == result) {
result=getChar(theChar);
if(kNoError==result) {
int pos=aTerminalSet.Find(theChar);
if(kNotFound!=pos) {
if(addTerminal)
aString+=theChar;
else push(theChar);
break;
}
else aString+=theChar;
}
}
return result;
}
/**
* Consumes chars until you see the given terminalChar
*
* @update gess 3/25/98
* @param
* @return error code
*/
int CScanner::readUntil(nsCString& aString, PRUnichar aTerminalChar, bool addTerminal) {
PRUnichar ch=0;
int result=kNoError;
while(kNoError==result) {
result=getChar(ch);
if(ch==aTerminalChar) {
if(addTerminal)
aString+=ch;
else push(ch);
break;
}
else aString+=ch;
}
return result;
}