/// <summary>
/// There are two general ways to use select()-step.
/// Select labeled steps within a path (as defined by as() in a traversal).
/// Select objects out of a Map<String,Object> flow (i.e. a sub-map).
/// When the set of keys or values (i.e. columns) of a path or map are needed, use select(keys)
/// and select(values), respectively. select() can also accept a traversal that emits a key
/// </summary>
/// <param name="builder"></param>
/// <param name="pop"></param>
/// <param name="traversal"></param>
/// <returns></returns>
public static GremlinQueryBuilder Select(this GremlinQueryBuilder builder, GremlinPopModifier pop, GremlinQueryBuilder traversal)
{
if (pop == null)
{
throw new ArgumentNullException(nameof(pop));
}
if (traversal == null)
{
throw new ArgumentNullException(nameof(traversal));
}
builder.AddArguments(traversal.GremlinArguments);
return(builder.Add($"select({pop.QueryStringValue},{builder.Query})"));
}
/// <summary>
/// There are two general ways to use select()-step.
/// Select labeled steps within a path (as defined by as() in a traversal).
/// Select objects out of a Map<String,Object> flow (i.e. a sub-map).
/// When the set of keys or values (i.e. columns) of a path or map are needed, use select(keys)
/// and select(values), respectively. select() can also accept a traversal that emits a key
/// </summary>
/// <param name="builder"></param>
/// <param name="pop"></param>
/// <param name="label"></param>
/// <returns></returns>
public static GremlinQueryBuilder Select(this GremlinQueryBuilder builder, GremlinPopModifier pop, IGremlinParameter label)
{
if (pop == null)
{
throw new ArgumentNullException(nameof(pop));
}
if (label == null)
{
throw new ArgumentNullException(nameof(label));
}
if (!(label.TrueValue is string))
{
throw new GremlinQueryBuilderException($"{nameof(Select)} only allows strings in " +
$"{nameof(label)} parameter and {label.TrueValue} " +
$"does not appear to be");
}
builder.AddArgument(label as GremlinArgument);
return(builder.Add($"select({pop.QueryStringValue},{label.QueryStringValue})"));
}