feat: inlay hints

internal/analysis/diagnostic_kind.go

@@ -17,8 +17,8 @@ const (
 	_ Severity = iota
 	ErrorSeverity
 	WarningSeverity
-	Information
-	Hint
+	InformationSeverity
+	HintSeverity
 )
 
 func SeverityToAnsiString(s Severity) string {
@@ -27,9 +27,9 @@ func SeverityToAnsiString(s Severity) string {
 		return ansi.ColorRed("Error")
 	case WarningSeverity:
 		return ansi.ColorYellow("Warning")
-	case Information:
+	case InformationSeverity:
 		return "Info"
-	case Hint:
+	case HintSeverity:
 		return "Hint"
 	default:
 		return utils.NonExhaustiveMatchPanic[string](s)
@@ -42,9 +42,9 @@ func SeverityToString(s Severity) string {
 		return "Error"
 	case WarningSeverity:
 		return "Warning"
-	case Information:
+	case InformationSeverity:
 		return "Info"
-	case Hint:
+	case HintSeverity:
 		return "Hint"
 	default:
 		return utils.NonExhaustiveMatchPanic[string](s)

internal/analysis/inlay_hints.go

@@ -0,0 +1,44 @@
+package analysis
+
+import (
+	"fmt"
+	"slices"
+
+	"github.com/formancehq/numscript/internal/parser"
+)
+
+type InlayHint struct {
+	Position parser.Position
+	Label    string
+}
+
+func GetInlayHints(
+	checkResult CheckResult,
+) []InlayHint {
+	if checkResult.Program.Vars == nil {
+		return nil
+	}
+
+	typePrinter := NewTypePrinter()
+
+	var hints []InlayHint
+	for _, decl := range checkResult.Program.Vars.Declarations {
+		shouldShowAsset := slices.Contains(
+			[]string{TypeMonetary, TypeAsset},
+			decl.Type.Name,
+		)
+
+		if !shouldShowAsset {
+			continue
+		}
+
+		t := checkResult.GetVarDeclType(decl)
+
+		hints = append(hints, InlayHint{
+			Position: decl.Type.End,
+			Label:    fmt.Sprintf("<%s>", typePrinter.Print(t)),
+		})
+	}
+
+	return hints
+}

internal/analysis/union_find.go

@@ -82,3 +82,42 @@ func TypeToString(r Type) string {
 
 	return utils.NonExhaustiveMatchPanic[string](r)
 }
+
+type TypePrinter struct {
+	nextId uint16
+	store  map[*TVar]uint16
+}
+
+func NewTypePrinter() TypePrinter {
+	return TypePrinter{
+		nextId: 0,
+		store:  make(map[*TVar]uint16),
+	}
+}
+
+func (p *TypePrinter) getVarId(v *TVar) uint16 {
+	prev, ok := p.store[v]
+	if ok {
+		return prev
+	}
+
+	id := p.nextId
+	p.nextId += 1
+	p.store[v] = id
+	return id
+}
+
+func (p *TypePrinter) Print(r Type) string {
+	r = r.Resolve()
+	switch r := r.(type) {
+	case *TVar:
+		return fmt.Sprintf("asset_%d", p.getVarId(r))
+
+	case *TAsset:
+		return string(*r)
+
+	}
+
+	return utils.NonExhaustiveMatchPanic[string](r)
+
+}

internal/lsp/handlers.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/formancehq/numscript/internal/analysis"
 	"github.com/formancehq/numscript/internal/jsonrpc2"
+	"github.com/formancehq/numscript/internal/lsp/lsp_types_extra"
 	"github.com/formancehq/numscript/internal/parser"
 	"github.com/formancehq/numscript/internal/utils"
 	"go.lsp.dev/protocol"
@@ -157,6 +158,25 @@ func (state *State) handleGetSymbols(params protocol.DocumentSymbolParams) []pro
 	return lspDocumentSymbols
 }
 
+func (state *State) handleGetInlayHints(params lsp_types_extra.InlayHintParams) []lsp_types_extra.InlayHint {
+	doc, ok := state.documents.Get(params.TextDocument.URI)
+	if !ok {
+		return nil
+	}
+
+	k := lsp_types_extra.InlayHintKindType
+	hints := analysis.GetInlayHints(doc.CheckResult)
+	var res []lsp_types_extra.InlayHint
+	for _, hint := range hints {
+		res = append(res, lsp_types_extra.InlayHint{
+			Position: ParserToLspPosition(hint.Position),
+			Label:    hint.Label,
+			Kind:     &k,
+		})
+	}
+	return res
+}
+
 func (state *State) handleCodeAction(params protocol.CodeActionParams) []protocol.CodeAction {
 	doc, ok := state.documents.Get(params.TextDocument.URI)
 	if !ok {
@@ -225,16 +245,19 @@ func toLspDiagnostic(d analysis.Diagnostic) protocol.Diagnostic {
 	}
 }
 
-var initializeResult protocol.InitializeResult = protocol.InitializeResult{
-	Capabilities: protocol.ServerCapabilities{
-		TextDocumentSync: protocol.TextDocumentSyncOptions{
-			OpenClose: true,
-			Change:    protocol.TextDocumentSyncKindFull,
+var initializeResult lsp_types_extra.InitializeResult = lsp_types_extra.InitializeResult{
+	Capabilities: lsp_types_extra.ServerCapabilities{
+		ServerCapabilities: protocol.ServerCapabilities{
+			TextDocumentSync: protocol.TextDocumentSyncOptions{
+				OpenClose: true,
+				Change:    protocol.TextDocumentSyncKindFull,
+			},
+			HoverProvider:          true,
+			DefinitionProvider:     true,
+			DocumentSymbolProvider: true,
+			CodeActionProvider:     true,
 		},
-		HoverProvider:          true,
-		DefinitionProvider:     true,
-		DocumentSymbolProvider: true,
-		CodeActionProvider:     true,
+		InlayHintProvider: true,
 	},
 	ServerInfo: &protocol.ServerInfo{
 		Name:    "numscript-ls",
@@ -266,7 +289,9 @@ func NewConn(objStream jsonrpc2.MessageStream) *jsonrpc2.Conn {
 			text := p.ContentChanges[len(p.ContentChanges)-1].Text
 			state.updateDocument(conn, p.TextDocument.URI, text)
 		}),
-
+		jsonrpc2.NewRequestHandler("textDocument/inlayHint", jsonrpc2.AsyncHandling, func(p lsp_types_extra.InlayHintParams, conn *jsonrpc2.Conn) any {
+			return state.handleGetInlayHints(p)
+		}),
 		jsonrpc2.NewRequestHandler("textDocument/hover", jsonrpc2.AsyncHandling, func(p protocol.HoverParams, conn *jsonrpc2.Conn) any {
 			return state.handleHover(p)
 		}),

internal/lsp/lsp_types_extra/types.go

@@ -0,0 +1,45 @@
+package lsp_types_extra
+
+import "go.lsp.dev/protocol"
+
+type InlayHintParams struct {
+	TextDocument protocol.TextDocumentIdentifier `json:"textDocument"`
+	Range        protocol.Range                  `json:"range"`
+}
+
+type InlayHintKind string
+
+const (
+	InlayHintKindType  InlayHintKind = "type"
+	InlayHintKindParam InlayHintKind = "parameter"
+)
+
+type InlayHint struct {
+	Position  protocol.Position   `json:"position"`
+	Label     string              `json:"label"`
+	Kind      *InlayHintKind      `json:"kind,omitempty"`
+	Tooltip   *string             `json:"tooltip,omitempty"`
+	TextEdits []protocol.TextEdit `json:"textEdits,omitempty"`
+}
+
+type InlayHintOptions struct {
+	ResolveProvider bool `json:"resolveProvider,omitempty"`
+}
+
+type InlayHintRegistrationOptions struct {
+	protocol.TextDocumentRegistrationOptions
+	InlayHintOptions
+}
+
+type InlayHintParamsResult []InlayHint
+
+// -- Initialize
+type ServerCapabilities struct {
+	protocol.ServerCapabilities
+	InlayHintProvider bool `json:"inlayHintProvider,omitempty"`
+}
+
+type InitializeResult struct {
+	Capabilities ServerCapabilities   `json:"capabilities"`
+	ServerInfo   *protocol.ServerInfo `json:"serverInfo,omitempty"`
+}