static bool TryCompileImpl(
string expression,
NameResolver?nameResolver,
[MaybeNullWhen(false)] out CompiledExpression result,
[MaybeNullWhen(true)] out string error)
{
if (!ExpressionParser.TryParse(expression, out var root, out error))
{
result = null;
return(false);
}
result = ExpressionCompiler.Compile(root, DefaultFunctionNameResolver.Build(nameResolver));
error = null;
return(true);
}
/// <summary>
/// Construct an <see cref="ExpressionTemplate"/>.
/// </summary>
/// <param name="template">The template text.</param>
/// <param name="formatProvider">Optionally, an <see cref="IFormatProvider"/> to use when formatting
/// embedded values.</param>
/// <param name="nameResolver">Optionally, a <see cref="NameResolver"/>
/// with which to resolve function names that appear in the template.</param>
public ExpressionTemplate(
string template,
IFormatProvider?formatProvider = null,
NameResolver?nameResolver = null)
{
if (template == null)
{
throw new ArgumentNullException(nameof(template));
}
if (!TemplateParser.TryParse(template, out var parsed, out var error))
{
throw new ArgumentException(error);
}
_compiled = TemplateCompiler.Compile(parsed, DefaultFunctionNameResolver.Build(nameResolver));
_formatProvider = formatProvider;
}
/// <summary>
/// Construct an <see cref="ExpressionTemplate"/>.
/// </summary>
/// <param name="template">The template text.</param>
/// <param name="formatProvider">Optionally, an <see cref="IFormatProvider"/> to use when formatting
/// embedded values.</param>
/// <param name="result">The parsed template, if successful.</param>
/// <param name="error">A description of the error, if unsuccessful.</param>
/// <param name="nameResolver">Optionally, a <see cref="NameResolver"/>
/// with which to resolve function names that appear in the template.</param>
/// <returns><c langword="true">true</c> if the template was well-formed.</returns>
public static bool TryParse(
string template,
IFormatProvider?formatProvider,
NameResolver?nameResolver,
[MaybeNullWhen(false)] out ExpressionTemplate result,
[MaybeNullWhen(true)] out string error)
{
if (template == null)
{
throw new ArgumentNullException(nameof(template));
}
if (!TemplateParser.TryParse(template, out var parsed, out error))
{
result = null;
return(false);
}
result = new ExpressionTemplate(TemplateCompiler.Compile(parsed, DefaultFunctionNameResolver.Build(nameResolver)), formatProvider);
return(true);
}