strfun.cpp

来自「小型搜索引擎,用C/C++编写,属于全文搜索引擎」· C++ 代码 · 共 58 行

#include "StrFun.h"

CStrFun::CStrFun()
{

}

CStrFun::~CStrFun()
{

}

void CStrFun::Str2Lower(string& str, int nLen)
{
        char distance='A'-'a' ;

        for( int i=0 ; i<nLen; i++ )
                if  ( str[i]>='A' && str[i]<='Z' )
                        str[i] -= distance ;
}

bool _nocase_compare(char c1, char c2)
{
        return toupper(c1) == toupper(c2);
}

string::size_type CStrFun::FindCase(string haystack, string needle)
{
	assert( haystack.empty() == false );
	assert( needle.empty() == false );

	string::iterator pos;
	pos = search(haystack.begin(), haystack.end(), 
		needle.begin(),needle.end(), _nocase_compare);

	if( pos == haystack.end()){
		return string::npos;
	}else{
		return (pos - haystack.begin());
	}
}

string::size_type CStrFun::FindCaseFrom(string haystack, string needle, int nFrom)
{
	assert( haystack.empty() == false );
	assert( needle.empty() == false );

	string::iterator pos;
	pos = search(haystack.begin()+nFrom, haystack.end(), 
		needle.begin(),needle.end(), _nocase_compare);

	if( pos == haystack.end()){
		return string::npos;
	}else{
		return (pos - haystack.begin());
	}
}