private static EvaluationResult ExpandEnvironmentVariablesInString(Context context, ModuleLiteral env, EvaluationStackFrame args)
{
var unexpandedString = Args.AsString(args, 0);
if (StringVariableExpander.TryExpandVariablesInString(unexpandedString, context.FrontEndHost.Engine, out string expandedString))
{
return(EvaluationResult.Create(expandedString));
}
// No expansion occurred
return(EvaluationResult.Create(unexpandedString));
}
/// <summary>
/// Replaces the name of each environment variable embedded in the specified path with the string equivalent of the value of the variable.
/// Replacement only occurs for environment variables that are set. Unset environment variables are left unexpanded.
/// </summary>
private static EvaluationResult ExpandEnvironmentVariablesInPath(Context context, ModuleLiteral env, EvaluationStackFrame args)
{
var path = Args.AsPath(args, 0);
var pathAsString = path.ToString(context.PathTable);
if (StringVariableExpander.TryExpandVariablesInString(pathAsString, context.FrontEndHost.Engine, out string expandedPath))
{
// The resulting expanded path may not be a valid one. Apply the same validations as when creating an absolute path from a literal
return(AmbientPath.CreateFromAbsolutePathString(context, expandedPath));
}
// No expansion occurred
return(EvaluationResult.Create(path));
}