//Copyright (c) Microsoft Corporation. All rights reserved.
using System;
using System.Collections.Generic;
using System.Text;
namespace Xml.Schema.Linq
{
internal static class XmlComplianceUtil
{
// Replaces \r\n, \n, \r and \t with single space (0x20) and then removes spaces
// at the beggining and and the end of the string and replaces sequences of spaces
// with a single space.
public static string NonCDataNormalize( string value ) {
int len = value.Length;
if ( len <= 0 ) {
return string.Empty;
}
int startPos = 0;
StringBuilder norValue = null;
while (IsWhiteSpace( value[startPos] ) ) {
startPos++;
if ( startPos == len ) {
return " ";
}
}
int i = startPos;
while ( i < len ) {
if ( !IsWhiteSpace( value[i] ) ) {
i++;
continue;
}
int j = i + 1;
while ( j < len && IsWhiteSpace( value[j] ) ) {
j++;
}
if ( j == len ) {
if ( norValue == null ) {
return value.Substring( startPos, i - startPos );
}
else {
norValue.Append( value, startPos, i - startPos );
return norValue.ToString();
}
}
if (j > i + 1 || value[i] != 0x20 ) {
if ( norValue == null ) {
norValue = new StringBuilder( len );
}
norValue.Append( value, startPos, i - startPos );
norValue.Append( (char)0x20 );
startPos = j;
i = j;
}
else {
i++;
}
}
if ( norValue != null ) {
if ( startPos < i ) {
norValue.Append( value, startPos, i - startPos );
}
return norValue.ToString();
}
else {
if ( startPos > 0 ) {
return value.Substring( startPos, len - startPos );
}
else {
return value;
}
}
}
// Replaces \r\n, \n, \r and \t with single space (0x20)
public static string CDataNormalize( string value ) {
int len = value.Length;
if ( len <= 0 ) {
return string.Empty;
}
int i = 0;
int startPos = 0;
StringBuilder norValue = null;
while ( i < len ) {
char ch = value[i];
if ( ch >= 0x20 || ( ch != 0x9 && ch != 0xA && ch != 0xD ) ) {
i++;
continue;
}
if ( norValue == null ) {
norValue = new StringBuilder( len );
}
if ( startPos < i ) {
norValue.Append( value, startPos, i - startPos );
}
norValue.Append( (char)0x20 );
if ( ch == 0xD && ( i+1 < len && value[i+1] == 0xA ) ) {
i += 2;
}
else {
i++;
}
startPos = i;
}
if ( norValue == null ) {
return value;
}
else {
if ( i > startPos ) {
norValue.Append(value, startPos, i-startPos);
}
return norValue.ToString();
}
}
internal static bool IsWhiteSpace(char c) {
switch(c) {
case (char)0x9:
case (char)0xA:
case (char)0xD:
case (char)0x20: return true;
default: return false;
}
}
}
}