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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
#nullable disable
using System;
using System.Collections.Generic;
using System.Linq;
namespace Microsoft.AspNetCore.Razor.Language;
/// <summary>
/// A descriptor type for a directive that can be parsed by the Razor parser.
/// </summary>
public abstract class DirectiveDescriptor
{
/// <summary>
/// Gets the description of the directive.
/// </summary>
/// <remarks>
/// The description is used for information purposes, and has no effect on parsing.
/// </remarks>
public abstract string Description { get; }
/// <summary>
/// Gets the directive keyword without the leading <c>@</c> token.
/// </summary>
public abstract string Directive { get; }
/// <summary>
/// Gets the display name of the directive.
/// </summary>
/// <remarks>
/// The display name is used for information purposes, and has no effect on parsing.
/// </remarks>
public abstract string DisplayName { get; }
/// <summary>
/// Gets the kind of the directive. The kind determines whether or not a directive has an associated block.
/// </summary>
public abstract DirectiveKind Kind { get; }
/// <summary>
/// Gets the way a directive can be used. The usage determines how many, and where directives can exist per document.
/// </summary>
public abstract DirectiveUsage Usage { get; }
/// <summary>
/// Gets the list of directive tokens that can follow the directive keyword.
/// </summary>
public abstract IReadOnlyList<DirectiveTokenDescriptor> Tokens { get; }
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/>.
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <param name="kind">The directive kind.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateDirective(string directive, DirectiveKind kind)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, kind, configure: null);
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/>.
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <param name="kind">The directive kind.</param>
/// <param name="configure">A configuration delegate for the directive.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateDirective(string directive, DirectiveKind kind, Action<IDirectiveDescriptorBuilder> configure)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
var builder = new DefaultDirectiveDescriptorBuilder(directive, kind);
configure?.Invoke(builder);
return builder.Build();
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/> with <see cref="Kind"/> set to <see cref="DirectiveKind.SingleLine"/>
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateSingleLineDirective(string directive)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, DirectiveKind.SingleLine, configure: null);
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/> with <see cref="Kind"/> set to <see cref="DirectiveKind.SingleLine"/>
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <param name="configure">A configuration delegate for the directive.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateSingleLineDirective(string directive, Action<IDirectiveDescriptorBuilder> configure)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, DirectiveKind.SingleLine, configure);
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/> with <see cref="Kind"/> set to <see cref="DirectiveKind.RazorBlock"/>
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateRazorBlockDirective(string directive)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, DirectiveKind.RazorBlock, configure: null);
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/> with <see cref="Kind"/> set to <see cref="DirectiveKind.RazorBlock"/>
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <param name="configure">A configuration delegate for the directive.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateRazorBlockDirective(string directive, Action<IDirectiveDescriptorBuilder> configure)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, DirectiveKind.RazorBlock, configure);
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/> with <see cref="Kind"/> set to <see cref="DirectiveKind.CodeBlock"/>
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateCodeBlockDirective(string directive)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, DirectiveKind.CodeBlock, configure: null);
}
/// <summary>
/// Creates a new <see cref="DirectiveDescriptor"/> with <see cref="Kind"/> set to <see cref="DirectiveKind.CodeBlock"/>
/// </summary>
/// <param name="directive">The directive keyword.</param>
/// <param name="configure">A configuration delegate for the directive.</param>
/// <returns>A <see cref="DirectiveDescriptor"/> for the created directive.</returns>
public static DirectiveDescriptor CreateCodeBlockDirective(string directive, Action<IDirectiveDescriptorBuilder> configure)
{
if (directive == null)
{
throw new ArgumentNullException(nameof(directive));
}
return CreateDirective(directive, DirectiveKind.CodeBlock, configure);
}
private class DefaultDirectiveDescriptorBuilder : IDirectiveDescriptorBuilder
{
public DefaultDirectiveDescriptorBuilder(string name, DirectiveKind kind)
{
Directive = name;
Kind = kind;
Tokens = new List<DirectiveTokenDescriptor>();
}
public string Description { get; set; }
public string Directive { get; }
public string DisplayName { get; set; }
public DirectiveKind Kind { get; }
public DirectiveUsage Usage { get; set; }
public IList<DirectiveTokenDescriptor> Tokens { get; }
public DirectiveDescriptor Build()
{
if (Directive.Length == 0)
{
throw new InvalidOperationException(Resources.FormatDirectiveDescriptor_InvalidDirectiveKeyword(Directive));
}
for (var i = 0; i < Directive.Length; i++)
{
if (!char.IsLetter(Directive[i]))
{
throw new InvalidOperationException(Resources.FormatDirectiveDescriptor_InvalidDirectiveKeyword(Directive));
}
}
var foundOptionalToken = false;
for (var i = 0; i < Tokens.Count; i++)
{
var token = Tokens[i];
foundOptionalToken |= token.Optional;
if (foundOptionalToken && !token.Optional)
{
throw new InvalidOperationException(Resources.DirectiveDescriptor_InvalidNonOptionalToken);
}
}
return new DefaultDirectiveDescriptor(Directive, Kind, Usage, Tokens.ToArray(), DisplayName, Description);
}
}
private class DefaultDirectiveDescriptor : DirectiveDescriptor
{
public DefaultDirectiveDescriptor(
string directive,
DirectiveKind kind,
DirectiveUsage usage,
DirectiveTokenDescriptor[] tokens,
string displayName,
string description)
{
Directive = directive;
Kind = kind;
Usage = usage;
Tokens = tokens;
DisplayName = displayName;
Description = description;
}
public override string Description { get; }
public override string Directive { get; }
public override string DisplayName { get; }
public override DirectiveKind Kind { get; }
public override DirectiveUsage Usage { get; }
public override IReadOnlyList<DirectiveTokenDescriptor> Tokens { get; }
}
}
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