nub-lang/compiler/NubLang.LSP/AstExtensions.cs

using NubLang.Ast;
using NubLang.Syntax;
using OmniSharp.Extensions.LanguageServer.Protocol.Models;
using Range = OmniSharp.Extensions.LanguageServer.Protocol.Models.Range;

namespace NubLang.LSP;

public static class AstExtensions
{
    public static Location ToLocation(this Node node)
    {
        if (node.Tokens.Count == 0)
        {
            return new Location();
        }

        return new Location
        {
            Uri = node.Tokens.First().Span.SourcePath,
            Range = new Range(node.Tokens.First().Span.StartLine - 1, node.Tokens.First().Span.StartColumn - 1, node.Tokens.Last().Span.EndLine - 1, node.Tokens.Last().Span.EndColumn - 1)
        };
    }

    public static Location ToLocation(this Token token)
    {
        return new Location
        {
            Uri = token.Span.SourcePath,
            Range = new Range(token.Span.StartLine - 1, token.Span.StartColumn - 1, token.Span.EndLine - 1, token.Span.EndColumn - 1)
        };
    }

    public static bool ContainsPosition(this Token token, int line, int character)
    {
        var startLine = token.Span.StartLine - 1;
        var startChar = token.Span.StartColumn - 1;
        var endLine = token.Span.EndLine - 1;
        var endChar = token.Span.EndColumn - 1;

        if (line < startLine || line > endLine) return false;

        if (line > startLine && line < endLine) return true;

        if (startLine == endLine)
        {
            return character >= startChar && character <= endChar;
        }

        if (line == startLine)
        {
            return character >= startChar;
        }

        if (line == endLine)
        {
            return character <= endChar;
        }

        return false;
    }

    public static bool ContainsPosition(this Node node, int line, int character)
    {
        if (node.Tokens.Count == 0)
        {
            return false;
        }

        var span = node.Tokens.First().Span;

        var startLine = span.StartLine - 1;
        var startChar = span.StartColumn - 1;
        var endLine = span.EndLine - 1;
        var endChar = span.EndColumn - 1;

        if (line < startLine || line > endLine) return false;

        if (line > startLine && line < endLine) return true;

        if (startLine == endLine)
        {
            return character >= startChar && character <= endChar;
        }

        if (line == startLine)
        {
            return character >= startChar;
        }

        if (line == endLine)
        {
            return character <= endChar;
        }

        return false;
    }

    public static FuncNode? FunctionAtPosition(this List<TopLevelNode> compilationUnit, int line, int character)
    {
        return compilationUnit
            .OfType<FuncNode>()
            .FirstOrDefault(x => x.ContainsPosition(line, character));
    }

    public static Node? DeepestNodeAtPosition(this List<TopLevelNode> compilationUnit, int line, int character)
    {
        return compilationUnit
            .SelectMany(x => x.DescendantsAndSelf())
            .Where(n => n.ContainsPosition(line, character))
            .OrderBy(n => n.Tokens.First().Span.StartLine)
            .ThenBy(n => n.Tokens.First().Span.StartColumn)
            .LastOrDefault();
    }
}