ficdown/Ficdown.Parser/Engine/RegexLib.cs

53 lines
2.0 KiB
C#

namespace Ficdown.Parser.Engine
{
using System.Text;
using System.Text.RegularExpressions;
internal static class RegexLib
{
public static Regex Anchors =
new Regex(
string.Format(@"(?<anchor>\[(?<text>{0})\]\([ ]*(?<href>{1})[ ]*\))", GetNestedBracketsPattern(),
GetNestedParensPattern()), RegexOptions.Singleline | RegexOptions.Compiled);
private const string RegexValidName = @"[a-zA-Z](-?[a-zA-Z0-9])*";
private static readonly string RegexHrefTarget = string.Format(@"\/({0})", RegexValidName);
private static readonly string RegexHrefConditions = string.Format(@"\?((!?{0})(&!?{0})*)?", RegexValidName);
private static readonly string RegexHrefToggles = string.Format(@"#({0})(\+{0})*", RegexValidName);
public static Regex Href =
new Regex(
string.Format(@"^(?<target>{0})?(?<conditions>{1})?(?<toggles>{2})?$", RegexHrefTarget,
RegexHrefConditions, RegexHrefToggles), RegexOptions.Compiled);
private const int _nestDepth = 6;
private static string RepeatString(string text, int count)
{
var sb = new StringBuilder(text.Length * count);
for (int i = 0; i < count; i++)
sb.Append(text);
return sb.ToString();
}
private static string _nestedBracketsPattern;
private static string GetNestedBracketsPattern()
{
if (_nestedBracketsPattern == null)
_nestedBracketsPattern =
RepeatString(@"(?>[^\[\]]+|\[", _nestDepth) + RepeatString(@"\])*", _nestDepth);
return _nestedBracketsPattern;
}
private static string _nestedParensPattern;
private static string GetNestedParensPattern()
{
if (_nestedParensPattern == null)
_nestedParensPattern =
RepeatString(@"(?>[^()\s]+|\(", _nestDepth) + RepeatString(@"\))*", _nestDepth);
return _nestedParensPattern;
}
}
}