/// <summary>
/// Creates context condition from text representation
/// </summary>
/// <param name="sourceModuleSection">string representing module between left and right context</param>
/// <param name="leftContextSection">string with names of modules which should be on left side of source</param>
/// <param name="rightContextSection">string with names of modules which should be on right side of source</param>
/// <returns>Delegate which returns true if given GenerationIndex meets condition described by provided
/// representation</returns>
/// <exception cref="ParserException">Thrown if some module in left or right context contains bracket</exception>
internal Rule <T> .ContextCondition ParseContextCondition(string sourceModuleSection, string leftContextSection,
string rightContextSection)
{
int sourceId = _moduleParser.GetModuleId(
HelperMethods.ReadModuleName(sourceModuleSection, 0, out var tmp));
var leftContext = _moduleParser.ParseModules(leftContextSection);
var leftContextIds = new List <int>();
foreach (var module in leftContext)
{
var details = module.Parameters;
if (details != null && details.Length > 0)
{
throw new ParserException("Parameters are not allowed in context conditions");
}
leftContextIds.Add(module.Id);
}
var rightContext = _moduleParser.ParseModules(rightContextSection);
var rightContextIds = new List <int>();
foreach (var module in rightContext)
{
var details = module.Parameters;
if (details != null && details.Length > 0)
{
throw new ParserException("Parameters are not allowed in context conditions");
}
rightContextIds.Add(module.Id);
}
return(generationIndex =>
{
if (generationIndex.Module.Id != sourceId)
{
return false;
}
int start = generationIndex.Index;
//Not enough modules to the left of source module
if (leftContextIds.Count > start)
{
return false;
}
//Not enough modules to the right of source module
if (rightContextIds.Count > generationIndex.Count - start - 1)
{
return false;
}
for (int i = 0; i < leftContextIds.Count; i++)
{
if (generationIndex[start - i - 1].Id != leftContextIds[leftContext.Length - i - 1])
{
return false;
}
}
for (int i = 0; i < rightContextIds.Count; i++)
{
if (generationIndex[start + i + 1].Id != rightContextIds[i])
{
return false;
}
}
return true;
});
}
