feat(aliases): Add signature help support; Improvements

handlers/aliases/fields/fields.go

@@ -5,14 +5,50 @@ import (
 	docvalues "config-lsp/doc-values"
 )
 
-var UserField = docvalues.UserValue("", false)
+var UserField = docvalues.DocumentationValue{
+	Documentation: "A user on the host machine. The user must have a valid entry in the passwd(5) database file.",
+	Value:         docvalues.UserValue("", false),
+}
 
-var PathField = docvalues.PathValue{
+var UserDeclaration = "`user`"
+
+var PathField = docvalues.DocumentationValue{
+	Documentation: "Append messages to file, specified by its absolute pathname",
+	Value: docvalues.PathValue{
 		RequiredType: docvalues.PathTypeFile,
+	},
 }
 
-var CommandField = docvalues.StringValue{}
+var PathDeclaration = "`/path/to/file`"
 
-var EmailField = docvalues.RegexValue{
+var CommandField = docvalues.DocumentationValue{
+	Documentation: "Pipe the message to command on its standard input. The command is run under the privileges of the daemon's unprivileged account.",
+	Value:         docvalues.StringValue{},
+}
+
+var CommandDeclaration = "`|command`"
+
+var EmailField = docvalues.DocumentationValue{
+	Documentation: "An email address in RFC 5322 format. If an address extension is appended to the user-part, it is first compared for an exact match.  It is then stripped so that an address such as user+ext@example.com will only use the part that precedes ‘+’ as a key.",
+	Value: docvalues.RegexValue{
 		Regex: *commondocumentation.EmailRegex,
+	},
 }
+
+var EmailDeclaration = "`user-part@domain-part`"
+
+var IncludeField = docvalues.DocumentationValue{
+	Documentation: "Include any definitions in file as alias entries. The format of the file is identical to this one.",
+	Value: docvalues.PathValue{
+		RequiredType: docvalues.PathTypeFile,
+	},
+}
+
+var IncludeDeclaration = "`include:/path/to/file`"
+
+var ErrorMessageField = docvalues.DocumentationValue{
+	Documentation: "A status code and message to return. The code must be 3 digits, starting 4XX (TempFail) or 5XX (PermFail). The message must be present and can be freely chosen.",
+	Value:         docvalues.StringValue{},
+}
+
+var ErrorDeclaration = "`error:code message`"

handlers/aliases/handlers/hover.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"config-lsp/handlers/aliases/ast"
+	"config-lsp/handlers/aliases/fields"
 	"config-lsp/handlers/aliases/indexes"
 	"config-lsp/utils"
 	"fmt"
@@ -100,44 +101,44 @@ func GetAliasValueTypeInfo(
 	case ast.AliasValueUser:
 		return []string{
 			"### User",
-			"`user`",
+			fields.UserDeclaration,
 			"",
-			"A user on the host machine. The user must have a valid entry in the passwd(5) database file.",
+			fields.UserField.Documentation,
 		}
 	case ast.AliasValueEmail:
 		return []string{
 			"### Email",
-			"`user-part@domain-part`",
+			fields.EmailDeclaration,
 			"",
-			"An email address in RFC 5322 format. If an address extension is appended to the user-part, it is first compared for an exact match.  It is then stripped so that an address such as user+ext@example.com will only use the part that precedes ‘+’ as a key.",
+			fields.EmailField.Documentation,
 		}
 	case ast.AliasValueInclude:
 		return []string{
 			"### Include",
-			"`include:/path/to/file`",
+			fields.IncludeDeclaration,
 			"",
-			"Include any definitions in file as alias entries. The format of the file is identical to this one.",
+			fields.IncludeField.Documentation,
 		}
 	case ast.AliasValueFile:
 		return []string{
 			"### File",
-			"`/path/to/file`",
+			fields.PathDeclaration,
 			"",
-			"Append messages to file, specified by its absolute pathname.",
+			fields.PathField.Documentation,
 		}
 	case ast.AliasValueCommand:
 		return []string{
 			"### Command",
-			"`|command`",
+			fields.CommandDeclaration,
 			"",
-			"Pipe the message to command on its standard input. The command is run under the privileges of the daemon's unprivileged account.",
+			fields.CommandField.Documentation,
 		}
 	case ast.AliasValueError:
 		return []string{
 			"### Error",
-			"`error:code message`",
+			fields.ErrorDeclaration,
 			"",
-			"A status code and message to return. The code must be 3 digits, starting 4XX (TempFail) or 5XX (PermFail). The message must be present and can be freely chosen.",
+			fields.ErrorMessageField.Documentation,
 		}
 	}
 

handlers/aliases/handlers/signature_help.go

@@ -0,0 +1,309 @@
+package handlers
+
+import (
+	"config-lsp/handlers/aliases/ast"
+	"strings"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func GetRootSignatureHelp(
+	activeParameter uint32,
+) *protocol.SignatureHelp {
+	index := uint32(0)
+	return &protocol.SignatureHelp{
+		ActiveSignature: &index,
+		Signatures: []protocol.SignatureInformation{
+			{
+				Label:           "<alias>: <value1>, <value2>, ...",
+				ActiveParameter: &activeParameter,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("<alias>") + 1),
+						},
+						Documentation: "The alias to define",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<alias>:")),
+							uint32(len("<alias>:") + len("<value1>")),
+						},
+						Documentation: "A value to associate with the alias",
+					},
+				},
+			},
+		},
+	}
+}
+
+func GetAllValuesSignatureHelp() *protocol.SignatureHelp {
+	index := uint32(0)
+	return &protocol.SignatureHelp{
+		Signatures: []protocol.SignatureInformation{
+			{
+				Label:           "<user>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("<user>")),
+						},
+					},
+				},
+			},
+			{
+				Label:           "<user>@<host>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("<user>")),
+						},
+					},
+					{
+						Label: []uint32{
+							uint32(len("<user>@")),
+							uint32(len("<user>@<host>")),
+						},
+					},
+				},
+			},
+			{
+				Label:           "<file>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("<file>")),
+						},
+					},
+				},
+			},
+			{
+				Label:           ":include:<file>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len(":include:")),
+						},
+					},
+				},
+			},
+			{
+				Label:           "|<command>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							1,
+						},
+					},
+				},
+			},
+			{
+				Label:           "error:<code> <message>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("error")),
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func GetValueSignatureHelp(
+	value ast.AliasValueInterface,
+	cursor uint32,
+) *protocol.SignatureHelp {
+	switch value.(type) {
+	case ast.AliasValueUser:
+		index := uint32(0)
+		return &protocol.SignatureHelp{
+			Signatures: []protocol.SignatureInformation{
+				{
+					Label:           "<user>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								0,
+								uint32(len("<user>")),
+							},
+						},
+					},
+				},
+				{
+					Label:           "<user>@<host>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								0,
+								uint32(len("<user>")),
+							},
+						},
+						{
+							Label: []uint32{
+								uint32(len("<user>@")),
+								uint32(len("<user>@") + len("<host>")),
+							},
+						},
+					},
+				},
+			},
+		}
+	case ast.AliasValueEmail:
+		isBeforeAtSymbol := cursor <= uint32(strings.Index(value.GetAliasValue().Value, "@"))
+
+		var index uint32
+
+		if isBeforeAtSymbol {
+			index = 0
+		} else {
+			index = 1
+		}
+
+		return &protocol.SignatureHelp{
+			Signatures: []protocol.SignatureInformation{
+				{
+					Label:           "<user>@<host>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								0,
+								uint32(len("<user>")),
+							},
+						},
+						{
+							Label: []uint32{
+								uint32(len("<user>@")),
+								uint32(len("<user>@") + len("<host>")),
+							},
+						},
+					},
+				},
+			},
+		}
+	case ast.AliasValueFile:
+		index := uint32(0)
+		return &protocol.SignatureHelp{
+			Signatures: []protocol.SignatureInformation{
+				{
+					Label:           "<file>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								0,
+								uint32(len("<file>")),
+							},
+						},
+					},
+				},
+			},
+		}
+	case ast.AliasValueInclude:
+		index := uint32(0)
+		return &protocol.SignatureHelp{
+			Signatures: []protocol.SignatureInformation{
+				{
+					Label:           "include:<file>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								uint32(len("include:")),
+								uint32(len("include:<file>")),
+							},
+						},
+					},
+				},
+			},
+		}
+	case ast.AliasValueCommand:
+		var index uint32
+
+		if cursor == 0 {
+			index = 0
+		} else {
+			index = 1
+		}
+
+		return &protocol.SignatureHelp{
+			Signatures: []protocol.SignatureInformation{
+				{
+					Label:           "|<command>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								0,
+								1,
+							},
+						},
+						{
+							Label: []uint32{
+								1,
+								uint32(1 + len("<command>")),
+							},
+						},
+					},
+				},
+			},
+		}
+	case ast.AliasValueError:
+		errorValue := value.(ast.AliasValueError)
+		var index uint32
+
+		if errorValue.Code == nil || cursor <= errorValue.Code.Location.End.Character {
+			index = 1
+		} else {
+			index = 2
+		}
+
+		return &protocol.SignatureHelp{
+			Signatures: []protocol.SignatureInformation{
+				{
+					Label:           "error:<code> <message>",
+					ActiveParameter: &index,
+					Parameters: []protocol.ParameterInformation{
+						{
+							Label: []uint32{
+								0,
+								uint32(len("error:")),
+							},
+						},
+						{
+							Label: []uint32{
+								uint32(len("error:")),
+								uint32(len("error:<code>")),
+							},
+						},
+						{
+							Label: []uint32{
+								uint32(len("error:<code> ")),
+								uint32(len("error:<code> <message>")),
+							},
+						},
+					},
+				},
+			},
+		}
+	}
+
+	return nil
+}

handlers/aliases/lsp/text-document-signature-help.go

@@ -0,0 +1,52 @@
+package lsp
+
+import (
+	"config-lsp/handlers/aliases"
+	"config-lsp/handlers/aliases/ast"
+	"config-lsp/handlers/aliases/handlers"
+
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.SignatureHelpParams) (*protocol.SignatureHelp, error) {
+	document := aliases.DocumentParserMap[params.TextDocument.URI]
+
+	line := params.Position.Line
+	character := params.Position.Character
+
+	if _, found := document.Parser.CommentLines[line]; found {
+		// Comment
+		return nil, nil
+	}
+
+	rawEntry, found := document.Parser.Aliases.Get(line)
+
+	if !found {
+		return handlers.GetRootSignatureHelp(0), nil
+	}
+
+	entry := rawEntry.(*ast.AliasEntry)
+
+	if entry.Key != nil && character >= entry.Key.Location.Start.Character && character <= entry.Key.Location.End.Character {
+		return handlers.GetRootSignatureHelp(0), nil
+	}
+
+	if entry.Values != nil && character >= entry.Values.Location.Start.Character && character <= entry.Values.Location.End.Character {
+		value := handlers.GetValueAtCursor(character, entry)
+
+		if value == nil {
+			// For some reason, this does not really work,
+			// When we return all, and then a user value is entered
+			// and the `GetValueSignatureHelp` is called, still the old
+			// signatures with all signature are shown
+			// return handlers.GetAllValuesSignatureHelp(), nil
+
+			return nil, nil
+		}
+
+		return handlers.GetValueSignatureHelp(*value, character), nil
+	}
+
+	return nil, nil
+}

root-handler/handler.go

@@ -31,6 +31,7 @@ func SetUpRootHandler() {
 		WorkspaceExecuteCommand:   WorkspaceExecuteCommand,
 		TextDocumentRename:        TextDocumentRename,
 		TextDocumentPrepareRename: TextDocumentPrepareRename,
+		TextDocumentSignatureHelp: TextDocumentSignatureHelp,
 	}
 
 	server := server.NewServer(&lspHandler, lsName, false)
@@ -41,6 +42,15 @@ func SetUpRootHandler() {
 func initialize(context *glsp.Context, params *protocol.InitializeParams) (any, error) {
 	capabilities := lspHandler.CreateServerCapabilities()
 	capabilities.TextDocumentSync = protocol.TextDocumentSyncKindFull
+	capabilities.SignatureHelpProvider = &protocol.SignatureHelpOptions{
+		TriggerCharacters: []string{
+			"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",
+			"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",
+			"0", "1", "2", "3", "4", "5", "6", "7", "8", "9",
+			"_", "-", ".", "/", ":", "@", "#", "!", "$", "%", "^", "&", "*", "(", ")", "+", "=", "[", "]", "{", "}", "<", ">", "?", ";", ",", "|",
+			" ",
+		},
+	}
 
 	if (*params.Capabilities.TextDocument.Rename.PrepareSupport) == true {
 		// Client supports rename preparation

root-handler/text-document-prepare-rename.go

@@ -1,8 +1,8 @@
 package roothandler
 
 import (
-	"github.com/tliron/glsp"
 	aliases "config-lsp/handlers/aliases/lsp"
+	"github.com/tliron/glsp"
 
 	protocol "github.com/tliron/glsp/protocol_3_16"
 )
@@ -35,4 +35,3 @@ func TextDocumentPrepareRename(context *glsp.Context, params *protocol.PrepareRe
 
 	panic("root-handler/TextDocumentPrepareRename: unexpected language" + *language)
 }
-

root-handler/text-document-signature-help.go

@@ -0,0 +1,37 @@
+package roothandler
+
+import (
+	aliases "config-lsp/handlers/aliases/lsp"
+
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.SignatureHelpParams) (*protocol.SignatureHelp, error) {
+	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
+
+	if language == nil {
+		showParseError(
+			context,
+			params.TextDocument.URI,
+			undetectableError,
+		)
+
+		return nil, undetectableError.Err
+	}
+
+	switch *language {
+	case LanguageHosts:
+		return nil, nil
+	case LanguageSSHDConfig:
+		return nil, nil
+	case LanguageFstab:
+		return nil, nil
+	case LanguageWireguard:
+		return nil, nil
+	case LanguageAliases:
+		return aliases.TextDocumentSignatureHelp(context, params)
+	}
+
+	panic("root-handler/TextDocumentSignatureHelp: unexpected language" + *language)
+}

utils/strings.go

@@ -51,3 +51,9 @@ func CountCharacterOccurrences(line string, character rune) int {
 
 	return count
 }
+
+var emptyRegex = regexp.MustCompile(`^\s*$`)
+
+func IsEmpty(s string) bool {
+	return emptyRegex.MatchString(s)
+}