/// <summary>
/// Creates a new scan token.
/// </summary>
/// <param name="type">Type of characters found.</param>
/// <param name="text">Characters found.</param>
/// <param name="start">Position of the first character found.</param>
/// <exception cref="ArgumentException">text was empty or null; type was <see cref="Mark"/> but text was more than one character; type was not understood.</exception>
public ScanToken(ScanTokenType type, string text, ScanPosition start)
{
Text = NotNullOrEmpty(text, nameof(text));
Type = type;
Start = start;
switch (type)
{
case ScanTokenType.Mark:
if (text.Length > 1)
{
throw new ArgumentException("Mark tokens must be a single character", nameof(text));
}
End = start;
break;
case ScanTokenType.Word:
case ScanTokenType.Space:
End = start + (uint)text.Length;
break;
case ScanTokenType.Newline:
End = new ScanPosition(start.Absolute + (uint)text.Length, start.Row + 1, 0);
break;
default:
throw new ArgumentException($"{type} is not a supported scan token type", nameof(type));
}
}
public void New_StoresValues()
{
var subject = new ScanPosition(1, 2, 3);
using (new AssertionScope())
{
subject.Absolute.Should().Be(1);
subject.Row.Should().Be(2);
subject.Column.Should().Be(3);
}
}
public void Plus_WithNonZero_ReturnsCorrectPosition()
{
var subject = new ScanPosition(100, 20, 30);
(subject + 25).Should().Be(new ScanPosition(125, 20, 55));
}
public void Plus_With0_ReturnsSamePosition()
{
var subject = new ScanPosition(100, 20, 30);
(subject + 0).Should().Be(subject);
}
/// <summary> /// Creates a new mark token. /// </summary> /// <param name="mark">Mark character found.</param> /// <param name="position">Position of the mark.</param> /// <returns>The new token.</returns> public static ScanToken Mark(char mark, ScanPosition position) => new ScanToken(ScanTokenType.Mark, mark.ToString(), position);
/// <summary> /// Creates a new newline token. /// </summary> /// <param name="newline">Newline character(s) found.</param> /// <param name="position">Position of the newline.</param> /// <returns>The new token.</returns> public static ScanToken Newline(string newline, ScanPosition position) => new ScanToken(ScanTokenType.Newline, newline, position);
/// <summary> /// Creates a new space token. /// </summary> /// <param name="space">Space characters found.</param> /// <param name="position">Position of the space(s).</param> /// <returns>The new token.</returns> public static ScanToken Space(string space, ScanPosition position) => new ScanToken(ScanTokenType.Space, space, position);
/// <summary> /// Creates a new word token. /// </summary> /// <param name="word">Word characters found.</param> /// <param name="position">Position of the word.</param> /// <returns>The new token.</returns> public static ScanToken Word(string word, ScanPosition position) => new ScanToken(ScanTokenType.Word, word, position);