Implement signature help

src/JETLS.jl

@@ -62,6 +62,7 @@
 mutable struct FullAnalysisResult
     staled::Bool
     last_analysis::Float64
+    actual2virtual::JET.Actual2Virtual
     const uri2diagnostics::Dict{URI,Vector{Diagnostic}}
     const analyzed_file_infos::Dict{URI,JET.AnalyzedFileInfo}
     const successfully_analyzed_file_infos::Dict{URI,JET.AnalyzedFileInfo}
@@ -117,9 +118,14 @@
     end
 end
 
+const DEFAULT_DOCUMENT_SELECTOR = DocumentFilter[
+    DocumentFilter(; language = "julia")
+]
+
 include("utils.jl")
 include("registration.jl")
 include("completions.jl")
+include("signature-help.jl")
 include("diagnostics.jl")
 
 """
@@ -247,6 +253,8 @@
         return handle_CompletionRequest(server, msg)
     elseif msg isa CompletionResolveRequest
         return handle_CompletionResolveRequest(server, msg)
+    elseif msg isa SignatureHelpRequest
+        return handle_SignatureHelpRequest(server, msg)
     elseif JETLS_DEV_MODE
         if isdefined(msg, :method)
             id = getfield(msg, :method)
@@ -314,12 +322,22 @@
         :textDocument, :completion, :dynamicRegistration) !== true
         completionProvider = completion_options()
         if JETLS_DEV_MODE
-            @info "Registering completion with `InitializeResponse`"
+            @info "Registering 'textDocument/completion' with `InitializeResponse`"
         end
     else
         completionProvider = nothing # will be registered dynamically
     end
 
+    if getpath(params.capabilities,
+        :textDocument, :signatureHelp, :dynamicRegistration) !== true
+        signatureHelpProvider = signature_help_options()
+        if JETLS_DEV_MODE
+            @info "Registering 'textDocument/signatureHelp' with `InitializeResponse`"
+        end
+    else
+        signatureHelpProvider = nothing # will be registered dynamically
+    end
+
     result = InitializeResult(;
         capabilities = ServerCapabilities(;
             positionEncoding = PositionEncodingKind.UTF16,
@@ -329,6 +347,7 @@
                 save = SaveOptions(;
                     includeText = true)),
             completionProvider,
+            signatureHelpProvider,
         ),
         serverInfo = (;
             name = "JETLS",
@@ -357,14 +376,26 @@
         :textDocument, :completion, :dynamicRegistration) === true
         push!(registrations, completion_registration())
         if JETLS_DEV_MODE
-            @info "Dynamically registering completion upon `InitializedNotification`"
+            @info "Dynamically registering 'textDocument/completion' upon `InitializedNotification`"
         end
     else
         # NOTE If completion's `dynamicRegistration` is not supported,
         # it needs to be registered along with initialization in the `InitializeResponse`,
         # since `CompletionRegistrationOptions` does not extend `StaticRegistrationOptions`.
     end
 
+    if getpath(state.init_params.capabilities,
+        :textDocument, :signatureHelp, :dynamicRegistration) === true
+        push!(registrations, signature_help_registration())
+        if JETLS_DEV_MODE
+            @info "Dynamically registering 'textDocument/signatureHelp' upon `InitializedNotification`"
+        end
+    else
+        # NOTE If completion's `dynamicRegistration` is not supported,
+        # it needs to be registered along with initialization in the `InitializeResponse`,
+        # since `SignatureHelpRegistrationOptions` does not extend `StaticRegistrationOptions`.
+    end
+
     register(server, registrations)
 end
 
@@ -500,7 +531,7 @@
     uri2diagnostics = jet_result_to_diagnostics(keys(analyzed_file_infos), result)
     successfully_analyzed_file_infos = copy(analyzed_file_infos)
     is_full_analysis_successful(result) || empty!(successfully_analyzed_file_infos)
-    analysis_result = FullAnalysisResult(false, time(), uri2diagnostics, analyzed_file_infos, successfully_analyzed_file_infos)
+    analysis_result = FullAnalysisResult(false, time(), result.res.actual2virtual, uri2diagnostics, analyzed_file_infos, successfully_analyzed_file_infos)
     return AnalysisContext(entry, analysis_result)
 end
 
@@ -528,6 +559,9 @@
     jet_result_to_diagnostics!(uri2diagnostics, result)
     analysis_context.result.staled = false
     analysis_context.result.last_analysis = time()
+    if is_full_analysis_successful(result)
+        analysis_context.result.actual2virtual = result.res.actual2virtual
+    end
 end
 
 # TODO This reverse map recording should respect the changes made in `include` chains

src/LSP/LSP.jl

@@ -17,6 +17,7 @@ include("lifecycle-messages/exit.jl")
 include("document-synchronization.jl")
 include("language-features/diagnostics.jl")
 include("language-features/completions.jl")
+include("language-features/signature-help.jl")
 include("workspace-features/workspace-folders.jl")
 include("workspace-features/files.jl")
 include("capabilities.jl")

src/LSP/capabilities.jl

@@ -28,6 +28,8 @@
 
     completionProvider::Union{CompletionOptions, Nothing} = nothing
 
+    signatureHelpProvider::Union{SignatureHelpOptions, Nothing} = nothing
+
     "Workspace specific server capabilities"
     workspace::Union{Nothing, @interface begin
         """
@@ -80,10 +82,10 @@ end
     # """
     # hover::Union{HoverClientCapabilities, Nothing} = nothing
 
-    # """
-    # Capabilities specific to the `textDocument/signatureHelp` request.
-    # """
-    # signatureHelp::Union{SignatureHelpClientCapabilities, Nothing} = nothing
+    """
+    Capabilities specific to the `textDocument/signatureHelp` request.
+    """
+    signatureHelp::Union{SignatureHelpClientCapabilities, Nothing} = nothing
 
     # """
     # Capabilities specific to the `textDocument/declaration` request.

src/LSP/language-features/signature-help.jl

@@ -0,0 +1,255 @@
+@interface SignatureHelpClientCapabilities begin
+    """
+    Whether signature help supports dynamic registration.
+    """
+    dynamicRegistration::Union{Nothing, Bool} = nothing
+
+    """
+    The client supports the following `SignatureInformation`
+    specific properties.
+    """
+    signatureInformation::Union{Nothing, @interface begin
+        """
+        Client supports the follow content formats for the documentation
+        property. The order describes the preferred format of the client.
+        """
+        documentationFormat::Union{Nothing, Vector{MarkupKind.Ty}} = nothing
+
+        """
+        Client capabilities specific to parameter information.
+        """
+        parameterInformation::Union{Nothing, @interface begin
+            """
+            The client supports processing label offsets instead of a
+            simple label string.
+
+            # Tags
+            - since - 3.14.0
+            """
+            labelOffsetSupport::Union{Nothing, Bool} = nothing
+        end} = nothing
+
+        """
+        The client supports the `activeParameter` property on
+        `SignatureInformation` literal.
+
+        # Tags
+        - since - 3.16.0
+        """
+        activeParameterSupport::Union{Nothing, Bool} = nothing
+    end} = nothing
+
+    """
+    The client supports to send additional context information for a
+    `textDocument/signatureHelp` request. A client that opts into
+    contextSupport will also support the `retriggerCharacters` on
+    `SignatureHelpOptions`.
+
+    # Tags
+    - since - 3.15.0
+    """
+    contextSupport::Union{Nothing, Bool} = nothing
+end
+
+@interface SignatureHelpOptions @extends WorkDoneProgressOptions begin
+    """
+    The characters that trigger signature help
+    automatically.
+    """
+    triggerCharacters::Union{Nothing, Vector{String}} = nothing
+
+    """
+    List of characters that re-trigger signature help.
+
+    These trigger characters are only active when signature help is already
+    showing. All trigger characters are also counted as re-trigger
+    characters.
+
+    # Tags
+    - since - 3.15.0
+    """
+    retriggerCharacters::Union{Nothing, Vector{String}} = nothing
+end
+
+@interface SignatureHelpRegistrationOptions @extends TextDocumentRegistrationOptions, SignatureHelpOptions begin
+end
+
+"""
+How a signature help was triggered.
+
+# Tags
+- since - 3.15.0
+"""
+@namespace SignatureHelpTriggerKind::Int begin
+    """
+    Signature help was invoked manually by the user or by a command.
+    """
+    Invoked = 1
+    """
+    Signature help was triggered by a trigger character.
+    """
+    TriggerCharacter = 2
+    """
+    Signature help was triggered by the cursor moving or by the document
+    content changing.
+    """
+    ContentChange = 3
+end
+
+"""
+Represents a parameter of a callable-signature. A parameter can
+have a label and a doc-comment.
+"""
+@interface ParameterInformation begin
+
+    """
+    The label of this parameter information.
+
+    Either a string or an inclusive start and exclusive end offsets within
+    its containing signature label. (see SignatureInformation.label). The
+    offsets are based on a UTF-16 string representation as `Position` and
+    `Range` does.
+
+    *Note*: a label of type string should be a substring of its containing
+    signature label. Its intended use case is to highlight the parameter
+    label part in the `SignatureInformation.label`.
+    """
+    label::Union{String, Vector{UInt}} # vector should have length 2
+
+    """
+    The human-readable doc-comment of this parameter. Will be shown
+    in the UI but can be omitted.
+    """
+    documentation::Union{Nothing, String, MarkupContent} = nothing
+end
+
+"""
+Represents the signature of something callable. A signature
+can have a label, like a function-name, a doc-comment, and
+a set of parameters.
+"""
+@interface SignatureInformation begin
+    """
+    The label of this signature. Will be shown in
+    the UI.
+    """
+    label::String
+
+    """
+    The human-readable doc-comment of this signature. Will be shown
+    in the UI but can be omitted.
+    """
+    documentation::Union{Nothing, String, MarkupContent} = nothing
+
+    """
+    The parameters of this signature.
+    """
+    parameters::Union{Nothing, Vector{ParameterInformation}} = nothing
+
+    """
+    The index of the active parameter.
+
+    If provided, this is used in place of `SignatureHelp.activeParameter`.
+
+     # Tags
+    - since - 3.16.0
+    """
+    activeParameter::Union{Nothing, UInt} = nothing
+end
+
+"""
+Signature help represents the signature of something
+callable. There can be multiple signature but only one
+active and only one active parameter.
+"""
+@interface SignatureHelp begin
+    """
+    One or more signatures. If no signatures are available the signature help
+    request should return `null`.
+    """
+    signatures::Vector{SignatureInformation}
+
+    """
+    The active signature. If omitted or the value lies outside the
+    range of `signatures` the value defaults to zero or is ignore if
+    the `SignatureHelp` as no signatures.
+
+    Whenever possible implementors should make an active decision about
+    the active signature and shouldn't rely on a default value.
+
+    In future version of the protocol this property might become
+    mandatory to better express this.
+    """
+    activeSignature::Union{Nothing, UInt} = nothing
+
+    """
+    The active parameter of the active signature. If omitted or the value
+    lies outside the range of `signatures[activeSignature].parameters`
+    defaults to 0 if the active signature has parameters. If
+    the active signature has no parameters it is ignored.
+    In future version of the protocol this property might become
+    mandatory to better express the active parameter if the
+    active signature does have any.
+    """
+    activeParameter::Union{Nothing, UInt} = nothing
+end
+
+"""
+Additional information about the context in which a signature help request
+was triggered.
+
+# Tags
+- since - 3.15.0
+"""
+@interface SignatureHelpContext begin
+    """
+    Action that caused signature help to be triggered.
+    """
+    triggerKind::SignatureHelpTriggerKind.Ty
+
+    """
+    Character that caused signature help to be triggered.
+
+    This is undefined when triggerKind !==
+    SignatureHelpTriggerKind.TriggerCharacter
+    """
+    triggerCharacter::Union{Nothing, String} = nothing
+
+    """
+    `true` if signature help was already showing when it was triggered.
+
+    Retriggers occur when the signature help is already active and can be
+    caused by actions such as typing a trigger character, a cursor move, or
+    document content changes.
+    """
+    isRetrigger::Bool
+
+    """
+    The currently active `SignatureHelp`.
+
+    The `activeSignatureHelp` has its `SignatureHelp.activeSignature` field
+    updated based on the user navigating through available signatures.
+    """
+    activeSignatureHelp::Union{Nothing, SignatureHelp} = nothing
+end
+
+@interface SignatureHelpParams @extends TextDocumentPositionParams, WorkDoneProgressParams begin
+    """
+    The signature help context. This is only available if the client
+    specifies to send this using the client capability
+    `textDocument.signatureHelp.contextSupport === true`
+
+    # Tags
+    - since - 3.15.0
+    """
+    context::Union{Nothing, SignatureHelpContext} = nothing
+end
+
+@interface SignatureHelpRequest @extends RequestMessage begin
+    method::String = "textDocument/signatureHelp"
+    params::SignatureHelpParams
+end
+
+@interface SignatureHelpResponse @extends ResponseMessage begin
+    result::Union{SignatureHelp, Null}
+end