/// True if str is a number
public static bool IsNumber(string str)
{
if (str == null)
{
throw new ArgumentNullException("str");
}
using (var sr = new ParsingReader(str))
{
if (sr.ReadNumber() == null)
{
return(false);
}
sr.SkipWhiteSpaceAndComments();
if (sr.Peek() != -1)
{
return(false);
}
}
return(true);
}
/// <summary>
/// Try to get variable value
/// </summary>
/// <param name="key">Variable name</param>
/// <param name="value">Where to store found variable value</param>
/// <returns>true if variable is set</returns>
public override bool TryGetValue(string key, out object value)
{
if (!IsCalculated(key))
{
return(base.TryGetValue(key, out value));
}
using (var sr = new ParsingReader(key))
{
sr.SkipWhiteSpace();
value = sr.ReadNumber();
if (value != null)
{
sr.SkipWhiteSpace();
sr.ReadAndThrowIfNot(-1);
return(true);
}
}
value = EvalMulti(key);
return(true);
}
/// Returns null if str is not a number, or its value otherwise
public static ValueType TryParseNumber(string stringToParse)
{
if (stringToParse == null)
{
return(null);
}
using (var sr = new ParsingReader(stringToParse))
{
sr.SkipWhiteSpaceAndComments();
ValueType o = sr.ReadNumber();
if (o == null)
{
return(null);
}
sr.SkipWhiteSpaceAndComments();
if (sr.Peek() != -1)
{
return(null);
}
return(o);
}
}
/// Parse string to a number. 10 and hex numbers (like 0x222) are allowed. Suffixes like 20.3f are also allowed.
public static ValueType ParseNumber(string str)
{
if (str == null)
{
throw new ArgumentNullException("str");
}
using (var sr = new ParsingReader(str))
{
sr.SkipWhiteSpaceAndComments();
ValueType o = sr.ReadNumber();
if (o == null)
{
throw new ParsingException("Invalid numeric expression at " + sr.ReadLine());
}
sr.SkipWhiteSpaceAndComments();
if (sr.Peek() != -1)
{
throw new ParsingException("Invalid numeric expression, unexpected characters at " + sr.ReadLine());
}
return(o);
}
}
/// <summary>
/// Try to get variable value
/// </summary>
/// <param name="key">Variable name</param>
/// <param name="value">Where to store found variable value</param>
/// <returns>true if variable is set</returns>
public override bool TryGetValue(string key, out object value)
{
if (!IsCalculated(key))
{
return(base.TryGetValue(key, out value));
}
using (var sr = new ParsingReader(key))
{
sr.SkipWhiteSpace();
value = sr.ReadNumber();
if (value != null)
{
sr.SkipWhiteSpace();
sr.ReadAndThrowIfNot(-1);
return(true);
}
}
if (!string.IsNullOrEmpty(key))
{
switch (key[0])
{
case '%':
EnvironmentVariableTarget target = getTarget(ref key);
value = Environment.GetEnvironmentVariable(key, target);
return(value != null);
case '~':
value = Find(key.Substring(1), true);
return(true);
}
}
value = EvalMulti(key);
return(true);
}
