Completions

compiler/NubLang.LSP/AstExtensions.cs

@@ -4,6 +4,43 @@ namespace NubLang.LSP;
 
 public static class AstExtensions
 {
+    public static bool ContainsPosition(this Node node, int line, int character)
+    {
+        if (node.Tokens.Count == 0)
+        {
+            return false;
+        }
+
+        var start = node.Tokens.First().Span.Start;
+        var end = node.Tokens.Last().Span.End;
+
+        var startLine = start.Line - 1;
+        var startChar = start.Column - 1;
+        var endLine = end.Line - 1;
+        var endChar = end.Column - 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 IEnumerable<Node> EnumerateDescendantsAndSelf(this Node node)
     {
         yield return node;

compiler/NubLang.LSP/CompletionHandler.cs

@@ -0,0 +1,181 @@
+using NubLang.Ast;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Document;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+
+namespace NubLang.LSP;
+
+internal class CompletionHandler(WorkspaceManager workspaceManager) : CompletionHandlerBase
+{
+    private readonly CompletionItem[] _definitionSnippets =
+    [
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "func",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "func ${1:name}(${2:params})\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "struct",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "struct ${1:name}\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "module",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "module \"$0\"",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "import",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "import \"$0\"",
+        }
+    ];
+
+    private readonly CompletionItem[] _statementSnippets =
+    [
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "let",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "let ${1:name} = $0",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "if",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "if ${1:condition}\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "else if",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "else if ${1:condition}\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "else",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "else\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "while",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "while ${1:condition}\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "for",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "for ${1:name}, ${2:index} in ${3:array}\n{\n    $0\n}",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "return",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "return $0",
+        },
+        new()
+        {
+            Kind = CompletionItemKind.Keyword,
+            Label = "defer",
+            InsertTextFormat = InsertTextFormat.Snippet,
+            InsertText = "defer $0",
+        }
+    ];
+
+    protected override CompletionRegistrationOptions CreateRegistrationOptions(CompletionCapability capability, ClientCapabilities clientCapabilities)
+    {
+        return new CompletionRegistrationOptions();
+    }
+
+    public override Task<CompletionList> Handle(CompletionParams request, CancellationToken cancellationToken)
+    {
+        return Task.FromResult(HandleSync(request, cancellationToken));
+    }
+
+    private CompletionList HandleSync(CompletionParams request, CancellationToken cancellationToken)
+    {
+        var completions = new List<CompletionItem>();
+        var position = request.Position;
+
+        var uri = request.TextDocument.Uri;
+        var compilationUnit = workspaceManager.GetCompilationUnit(uri);
+        if (compilationUnit != null)
+        {
+            var function = compilationUnit.Functions.FirstOrDefault(x => x.Body != null && x.Body.ContainsPosition(position.Line, position.Character));
+            if (function != null)
+            {
+                completions.AddRange(_statementSnippets);
+
+                foreach (var prototype in compilationUnit.ImportedFunctions)
+                {
+                    var parameterStrings = new List<string>();
+                    foreach (var (index, parameter) in prototype.Parameters.Index())
+                    {
+                        parameterStrings.AddRange($"${{{index + 1}:{parameter.Name}}}");
+                    }
+
+                    completions.Add(new CompletionItem
+                    {
+                        Kind = CompletionItemKind.Function,
+                        Label = $"{prototype.Module}::{prototype.Name}",
+                        InsertTextFormat = InsertTextFormat.Snippet,
+                        InsertText = $"{prototype.Module}::{prototype.Name}({string.Join(", ", parameterStrings)})",
+                    });
+                }
+
+                foreach (var parameter in function.Prototype.Parameters)
+                {
+                    completions.Add(new CompletionItem
+                    {
+                        Kind = CompletionItemKind.Variable,
+                        Label = parameter.Name,
+                        InsertText = parameter.Name,
+                    });
+                }
+
+                var variables = function
+                    .Body!
+                    .EnumerateDescendantsAndSelf()
+                    .OfType<VariableDeclarationNode>();
+
+                foreach (var variable in variables)
+                {
+                    completions.Add(new CompletionItem
+                    {
+                        Kind = CompletionItemKind.Variable,
+                        Label = variable.Name,
+                        InsertText = variable.Name,
+                    });
+                }
+            }
+            else
+            {
+                completions.AddRange(_definitionSnippets);
+            }
+        }
+
+        return new CompletionList(completions, false);
+    }
+
+    public override Task<CompletionItem> Handle(CompletionItem request, CancellationToken cancellationToken)
+    {
+        return Task.FromResult(new CompletionItem());
+    }
+}

compiler/NubLang.LSP/HoverHandler.cs

@@ -18,10 +18,10 @@ internal class HoverHandler(WorkspaceManager workspaceManager) : HoverHandlerBas
 
     public override Task<Hover?> Handle(HoverParams request, CancellationToken cancellationToken)
     {
-        return Task.FromResult(HandleSync(request));
+        return Task.FromResult(HandleSync(request, cancellationToken));
     }
 
-    private Hover? HandleSync(HoverParams request)
+    private Hover? HandleSync(HoverParams request, CancellationToken cancellationToken)
     {
         var compilationUnit = workspaceManager.GetCompilationUnit(request.TextDocument.Uri);
         if (compilationUnit == null)
@@ -34,7 +34,7 @@ internal class HoverHandler(WorkspaceManager workspaceManager) : HoverHandlerBas
 
         var hoveredNode = compilationUnit.Functions
             .SelectMany(x => x.EnumerateDescendantsAndSelf())
-            .Where(n => IsHoveringOverNode(n, line, character))
+            .Where(n => n.ContainsPosition(line, character))
             .OrderBy(n => n.Tokens.First().Span.Start.Line)
             .ThenBy(n => n.Tokens.First().Span.Start.Column)
             .LastOrDefault();
@@ -155,41 +155,4 @@ internal class HoverHandler(WorkspaceManager workspaceManager) : HoverHandlerBas
                 ```
                 """;
     }
-
-    private static bool IsHoveringOverNode(Node node, int line, int character)
-    {
-        if (node.Tokens.Count == 0)
-        {
-            return false;
-        }
-
-        var start = node.Tokens.First().Span.Start;
-        var end = node.Tokens.Last().Span.End;
-
-        var startLine = start.Line - 1;
-        var startChar = start.Column - 1;
-        var endLine = end.Line - 1;
-        var endChar = end.Column - 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;
-    }
 }

compiler/NubLang.LSP/Program.cs

@@ -16,9 +16,9 @@ var server = await LanguageServer.From(options => options
         .SetMinimumLevel(LogLevel.Debug))
     .WithHandler<TextDocumentSyncHandler>()
     .WithHandler<HoverHandler>()
+    .WithHandler<CompletionHandler>()
     .OnInitialize((server, request, ct) =>
     {
-        server.SendNotification("TEST");
         var workspaceManager = server.GetRequiredService<WorkspaceManager>();
 
         if (request.RootPath != null)