private static IEnumerable <SelectColumn> _Parse(Benumerator <char> en)
{
// Next value MUST be "SELECT "
if (en.Current != 'S' || !en.MoveNext() ||
en.Current != 'E' || !en.MoveNext() ||
en.Current != 'L' || !en.MoveNext() ||
en.Current != 'E' || !en.MoveNext() ||
en.Current != 'C' || !en.MoveNext() ||
en.Current != 'T' || !en.MoveNext() ||
en.Current != ' ' || !en.MoveNext()
)
{
throw new Exception("failed to parse SELECT. Expecting SELECT keyword");
}
// I am very lazily forcing the use of * for now
foreach (var col in SelectColumn.Parse(en, true))
{
yield return(col);
}
}
public static new Insert Parse(Benumerator <char> en)
{
if (!en.MoveNext() || en.Current == ' ' && !en.MoveNext())
{
throw new Exception("failed to parse. No Input");
}
if (!Parser.HasValue(en, "INSERT INTO "))
{
throw new Exception("failed to parse INSERT. Expecting 'INSERT INTO '");
}
var tableName = Parser.ParseWord(en);
Parser.SkipWhitespace(en);
if (!Parser.HasValue(en, "("))
{
throw new Exception("failed to parse INSERT. Expecting '('");
}
var columns = SelectColumn.Parse(en).ToArray();
Parser.SkipWhitespace(en);
if (!Parser.HasValue(en, ")"))
{
throw new Exception("failed to parse INSERT. Expecting ')'");
}
Parser.SkipWhitespace(en);
if (!Parser.HasValue(en, "VALUES"))
{
throw new Exception("failed to parse INSERT. Expecting ')'");
}
List <SelectColumn[]> rows = new List <SelectColumn[]>();
do
{
Parser.SkipWhitespace(en);
if (!Parser.HasValue(en, "("))
{
throw new Exception("failed to parse INSERT. Expecting ')'");
}
Parser.SkipWhitespace(en);
var values = SelectColumn.Parse(en).ToArray();
if (values.Length != columns.Length)
{
throw new Exception("failed to parse INSERT. Number of values do not match number of columns");
}
rows.Add(values);
Parser.SkipWhitespace(en);
if (!Parser.HasValue(en, ")"))
{
throw new Exception("failed to parse INSERT. Expecting ')'");
}
Parser.SkipWhitespace(en);
} while (Parser.HasValue(en, ","));
return(new Insert
{
tableName = tableName,
columns = columns,
rows = rows
});
}
