Enso Protocol Language Server Message Specification

This document contains the specification of the Enso protocol messages that pertain to the language server component. Please familiarise yourself with the common features of the protocol before reading this document.

For information on the design and architecture of the protocol, as well as its transport formats, please look here.

Types

There are a number of types that are used only within the language server’s protocol messages. These are specified here.

ExpressionId

An identifier used for Enso expressions.

type ExpressionId = UUID;

ContextId

An identifier used for execution contexts.

type ContextId = UUID;

StackItem

A representation of an executable position in code, used by the execution APIs.

ExplicitCall is a call performed at the top of the stack, to initialize the context with first execution. The thisArgumentsPosition field can be omitted, in which case the context will try to infer the argument on a best-effort basis. E.g. for a module-level method, or a method defined on a parameter-less atom type, this will be substituted for the unambiguous singleton instance.

LocalCall is a call corresponding to “entering a function call”.

type StackItem = ExplicitCall | LocalCall;

interface ExplicitCall {
  methodPointer: MethodPointer;
  thisArgumentExpression?: String;
  positionalArgumentsExpressions: String[];
}

interface LocalCall {
  expressionId: ExpressionId;
}

MethodPointer

Points to a method definition.

interface MethodPointer {
  /** The fully qualified module name. */
  module: String;

  /** The type on which the method is defined. */
  definedOnType: String;

  /** The method name. */
  name: String;
}

ProfilingInfo

Profiling information on an executed expression. It is implemented as a union as additional types of information will be added in the future.

type ProfilingInfo = ExecutionTime;

Where:

interface ExecutionTime {
  /** The time elapsed during the expression's evaluation, in nanoseconds */
  nanoTime: Number;
}

ExpressionUpdate

An update about the computed expression.

interface ExpressionUpdate {
  /**
   * The id of updated expression.
   */
  expressionId: ExpressionId;

  /**
   * The updated type of the expression.
   */
  type?: String;

  /**
   * The updated pointer to the method call.
   */
  methodPointer?: SuggestionId;

  /**
   * Profiling information about the expression.
   */
  profilingInfo: ProfilingInfo[];

  /**
   * Wether or not the expression's value came from the cache.
   */
  fromCache: bool;

  /**
   * An extra information about the computed value.
   */
  payload: ExpressionUpdatePayload;
}

ExpressionUpdatePayload

An information about the computed value.

type ExpressionUpdatePayload = Value | DatafalowError | Panic;

/**
 * An empty payload. Indicates that the expression was computed to a value.
 */
interface Value {}

/**
 * Indicates that the expression was computed to an error.
 */
interface DataflowError {
  /**
   * The list of expressions leading to the root error.
   */
  trace: ExpressionId[];
}

/**
 * Indicates that the expression failed with the runtime exception.
 */
interface Panic {
  /**
   * The error message.
   */
  message: String;

  /**
   * The stack trace.
   */
  trace: ExpressionId[];
}

VisualisationConfiguration

A configuration object for properties of the visualisation.

interface VisualisationConfiguration {
  /**
   * An execution context of the visualisation.
   */
  executionContextId: UUID;
  /**
   * A qualified name of the module containing the expression which creates
   * visualisation.
   */
  visualisationModule: String;
  /**
   * The expression that creates a visualisation.
   */
  expression: String;
}

SuggestionEntryArgument

The argument of a SuggestionEntry.

Format

// The argument of an atom, method or function suggestion
interface SuggestionEntryArgument {
  // The argument name
  name: string;
  // The arguement type. String 'Any' is used to specify genric types
  type: string;
  // Indicates whether the argument is lazy
  isSuspended: bool;
  // Indicates whether the argument has default value
  hasDefault: bool;
  // Optional default value
  defaultValue?: string;
}

SuggestionEntry

The language construct that can be returned as a suggestion.

Format

// The definition scope
interface SuggestionEntryScope {
  // The start position of the definition scope
  start: Position;
  // The end position of the definition scope
  end: Position;
}

// A type of suggestion entries.
type SuggestionEntry =
  // A module
  | SuggestionEntryModule
  // A value constructor
  | SuggestionEntryAtom
  // A method defined on a type
  | SuggestionEntryMethod
  // A function
  | SuggestionEntryFunction
  // A local value
  | SuggestionEntryLocal;

interface SuggestionEntryModule {
  /** The fully qualified module name. */
  module: string;

  /** The documentation string. */
  documentation?: string;

  /** The fully qualified module name re-exporting this module. */
  reexport?: string;

  /** The rendered HTMl of the documentation string. */

  documentationHtml?: string;
}

interface SuggestionEntryAtom {
  /** The external id. */
  externalId?: UUID;

  /** The atom name. */
  name: string;

  /** The module name where the atom is defined. */
  module: string;

  /** The list of arguments. */
  arguments: SuggestionEntryArgument[];

  /** The type of an atom. */
  returnType: string;

  /** The documentation string. */
  documentation?: string;

  /** The fully qualified module name re-exporting this module. */
  reexport?: string;

  /** The rendered HTMl of the documentation string. */

  documentationHtml?: string;
}

interface SuggestionEntryMethod {
  /** The external id. */
  externalId?: UUID;

  /** The method name. */
  name: string;

  /** The module name where this method is defined. */
  module: string;

  /** The list of arguments. */
  arguments: SuggestionEntryArgument[];

  /** The method self type. */
  selfType: string;

  /** The return type of this method. */
  returnType: string;

  /** The documentation string. */
  documentation?: string;

  /** The fully qualified module name re-exporting this module. */
  reexport?: string;

  /** The rendered HTMl of the documentation string. */

  documentationHtml?: string;
}

interface SuggestionEntryFunction {
  /** The external id. */
  externalId?: UUID;

  /** The function name. */
  name: string;

  /** The module name where this function is defined. */
  module: string;

  /** The list of arguments. */
  arguments: SuggestionEntryArgument[];

  /** The function return type. */
  returnType: string;

  /** The scope where the function is defined. */
  scope: SuggestionEntryScope;

  /** The rendered HTMl of the documentation string. */

  documentationHtml?: string;
}

interface SuggestionEntryLocal {
  /** The external id. */
  externalId?: UUID;

  /** The name of a value. */
  name: string;

  /** The module where this value is defined. */
  module: string;

  /** The type of a value. */
  returnType: string;

  /** The scope where the value is defined. */
  scope: SuggestionEntryScope;

  /** The rendered HTMl of the documentation string. */

  documentationHtml?: string;
}

SuggestionEntryType

The suggestion entry type that is used as a filter in search requests.

Format

// The kind of a suggestion.
type SuggestionEntryType = Module | Atom | Method | Function | Local;

SuggestionId

The suggestion entry id of the suggestions database.

Format

type SuggestionId = number;

SuggestionsDatabaseEntry

Format

The entry in the suggestions database.

interface SuggestionsDatabaseEntry {
  /**
   * The suggestion entry id.
   */
  id: SuggestionId;

  /**
   * The suggestion entry.
   */
  suggestion: SuggestionEntry;
}

SuggestionsOrderDatabaseEntry

The entry in the suggestions order database.

Format

interface SuggestionsOrderDatabaseEntry {
  /**
   * The unique identifier of a suggestion referring to the `id` identifier of
   * the suggestions database.
   */
  suggestionId: SuggestionId;

  /**
   * The suggestion that goes before this one in the source file.
   */
  prevId?: SuggestionId;

  /**
   * Ths suggestion that goes after this one in the source file.
   */
  nextId?: SuggestionId;
}

FieldAction

The modifying action on a record field.

Format

type FieldAction = Remove | Set;

FieldUpdate

An object representing a modification of a field in a record.

Format

interface FieldUpdate<T> {
  /**
   * The modifying action.
   */
  tag: FieldAction;

  /**
   * The updated value.
   */
  value?: T;
}

SuggestionArgumentUpdate

An operation applied to the suggestion argument.

Format

type SuggestionArgumentUpdate = Add | Remove | Modify;

interface Add {
  /**
   * The position of the argument.
   */
  index: int;

  /**
   * The argument to add.
   */
  argument: SuggestionEntryArgument;
}

interface Remove {
  /**
   * The position of the argument.
   */
  index: int;
}

interface Modify {
  /**
   * The position of the argument.
   */
  index: int;

  /**
   * The name to update.
   */
  name?: FieldUpdate<String>;

  /**
   * The argument type to update.
   */
  reprType?: FieldUpdate<String>;

  /**
   * The isSuspended flag to update.
   */
  isSuspended?: FieldUpdate<Boolean>;

  /**
   * The hasDefault flag to update.
   */
  hasDefault?: FieldUpdate<Boolean>;

  /**
   * The default value to update.
   */
  defaultValue?: FieldUpdate<String>;
}

SuggestionsDatabaseUpdate

The update of the suggestions database.

Format

/**
 * The kind of the suggestions database update.
 */
type SuggestionsDatabaseUpdate = Add | Remove | Modify;

interface Add {
  /**
   * Suggestion entry id.
   */
  id: SuggestionId;

  /**
   * Suggestion entry.
   */
  suggestion: SuggestionEntry;
}

interface Remove {
  /**
   * Suggestion entry id.
   */
  id: SuggestionId;
}

interface Modify {
  /**
   * Suggestion entry id.
   */
  id: SuggestionId;

  /**
   * The external id to update.
   */
  externalId?: FieldUpdate<UUID>;

  /**
   * The list of argument updates.
   */
  arguments?: SuggestionArgumentUpdate[];

  /**
   * The module name to update.
   */
  module?: FieldUpdate<String>;

  /**
   * The self type to update.
   */
  selfType?: FieldUpdate<String>;

  /**
   * The return type to update.
   */
  returnType?: FieldUpdate<String>;

  /**
   * The documentation string to update.
   */
  documentation?: FieldUpdate<String>;

  /**
   * The scope to update.
   */
  scope?: FieldUpdate<SuggestionEntryScope>;

  /**
   * The reexport field to update.
   */
  reexport?: FieldUpdate<String>;
}

SuggestionsOrderDatabaseUpdate

The update of the suggestions order database.

Format

/**
 * The kind of the suggestions order database update.
 */
type SuggestionsOrderDatabaseUpdate = AddOrder | RemoveOrder | ModifyOrder;

interface AddOrder {
  entry: SuggestionOrderDatabaseEntry;
}

interface RemoveOrder {
  /**
   * The unique identifier of a suggestion.
   */
  suggestionId: SuggestionId;
}

interface ModifyOrder {
  /**
   * The unique identifier of a suggestion.
   */
  suggestionId: SuggestionId;

  /**
   * The previous suggestion id to update.
   */
  prevId?: FieldUpdate<SuggestionId>;

  /**
   * The next suggestion id to update.
   */
  nextId?: FieldUpdate<SuggestionId>;
}

Export

The info about module re-export.

Format

type Export = Qualified | Unqualified;

interface Qualified {
  /**
   * The module that re-exports the given module.
   */
  module: String;

  /**
   * The new name of the given module if it was renamed in the export clause.
   *
   * I.e. `X` in `export A.B as X`.
   */
  alias?: String;
}

interface Unqualified {
  /**
   * The module name that re-exports the given module.
   */
  module: String;
}

File

A representation of a file on disk.

Format

interface File {
  name: String; // Includes the file extension
  type: String;
}

DirectoryTree

A directory tree is a recursive type used to represent tree structures of files and directories. It contains files and symlinks in the files section and directories in the directories section. When the tree was requested with the parameter limiting the maximum depth, the bottom of the DirectoryTree will contain Directory node in the files section indicating that there is a directory, but the contents are unknown because we’ve reached the maximum depth.

Format

interface DirectoryTree {
  path: Path;
  name: String;
  files: [FileSystemObject];
  directories: [DirectoryTree];
}

FileAttributes

A description of the attributes of a file required by the IDE. These attributes may be expanded in future.

Format

/**
 * A representation of the attributes of a file.
 *
 * @param creationTime creation time
 * @param lastAccessTime last access time
 * @param lastModifiedTime last modified time
 * @param kind type of [[FileSystemObject]], can be: `Directory`, `File`, `Other`
 * @param byteSize size in bytes
 */
interface FileAttributes {
  creationTime: UTCDateTime;
  lastAccessTime: UTCDateTime;
  lastModifiedTime: UTCDateTime;
  kind: FileSystemObject;
  byteSize: number;
}

UTCDateTime

Time in UTC time zone represented as ISO-8601 string

Format

type UTCDateTime = String;

FileEventKind

The kind of event being described for a watched file.

Format

type FileEventKind = Added | Removed | Modified;

Position

A representation of a position in a text file.

Format

interface Position {
  /**
   * Line position in a document (zero-based).
   */
  line: number;

  /**
   * Character offset on a line in a document (zero-based). Assuming that the
   * line is represented as a string, the `character` value represents the gap
   * between the `character` and `character + 1`.
   *
   * If the character value is greater than the line length it defaults back to
   * the line length.
   */
  character: number;
}
namespace org.enso.languageserver.protocol.binary;

struct Position {
  // Line position in a document (zero-based)
  line: uint64;
  // Character offset on a line in a document (zero-based)
  character: uint64;
}

Range

A representation of a range of text in a text file.

Format

interface Range {
  /**
   * The range's start position.
   */
  start: Position;

  /**
   * The range's end position.
   */
  end: Position;
}

TextEdit

A representation of a change to a text file at a given position.

Format

interface TextEdit {
  range: Range;
  text: String;
}

DiagnosticType

The type of diagnostic message.

Format

type DiagnosticType = Error | Warning;

StackTraceElement

The frame of the stack trace. If the error refer to a builtin node, the path and location fields will be empty.

Format

interface StackTraceElement {
  /**
   * The function name containing the stack trace element.
   */
  functionName: String;

  /**
   * The location of the file.
   */
  path?: Path;

  /**
   * The location of the element in a file.
   */
  location?: Range;
}

Diagnostic

A diagnostic object is produced as a result of an execution attempt, like pushing the method pointer to a call stack, or editing the file. It can represent a compiler warning, a compilation error, or a runtime error. The message has optional path, location and stack fields containing information about the location in the source code.

In case of the runtime errors, the path and location fields may be empty if the error happens in a builtin node. Then, to locate the error in the code, you can use the stack field with a stack trace to find the first element with non-empty location (as the head of the stack will point to the builtin element).

Format

interface Diagnostic {
  /**
   * The type of diagnostic message.
   */
  kind: DiagnosticType;

  /**
   * The diagnostic message.
   */
  message: String;

  /**
   * The location of a file containing the diagnostic.
   */
  path?: Path;

  /**
   * The location of the diagnostic object in a file.
   */
  location?: Range;

  /**
   * The id of related expression.
   */
  expressionId?: ExpressionId;

  /**
   * The stack trace.
   */
  stack: StackTraceElement[];
}

SHA3-224

The SHA3-224 message digest encoded as a base16 string. For the equivalent structure on the binary connection please see EnsoDigest

Format

type SHA3-224 = String;

FileEdit

A representation of a batch of edits to a file, versioned.

SHA3-224 represents hash of the file contents. oldVersion is the version you’re applying your update on, newVersion is what you compute as the hash after applying the changes. In other words,

hash(origFile) == oldVersion
hash(applyEdits(origFile, edits)) == newVersion

it’s a sanity check to make sure that the diffs are applied consistently.

Consecutive text edits are applied sequentially, every one acting on the result of applying previous ones on the original buffer contents. In pseudocode:

applyEdits buffer [] = buffer
applyEdits buffer (first : rest) = applyEdits (applyTextEdit buffer first) rest

Format

interface FileEdit {
  path: Path;
  edits: [TextEdit];
  oldVersion: SHA3-224;
  newVersion: SHA3-224;
}

FileContents

A representation of the contents of a file.

Format

interface FileContents<T> {
  contents: T;
}

class TextFileContents extends FileContents<String> {}

FileSystemObject

A representation of what kind of type a filesystem object can be.

Format

type FileSystemObject = Directory | SymlinkLoop | File | Other;

/**
 * Represents a directory.
 *
 * @param name a name of the directory
 * @param path a path to the directory
 */
interface Directory {
  name: String;
  path: Path;
}

/**
 * Represents a symbolic link that creates a loop.
 *
 * @param name a name of the symlink
 * @param path a path to the symlink
 * @param target a target of the symlink. Since it is a loop,
 * target is a subpath of the symlink
 */
interface SymlinkLoop {
  name: String;
  path: Path;
  target: Path;
}

/**
 * Represents a file.
 *
 * @param name a name of the file
 * @param path a path to the file
 */
interface File {
  name: String;
  path: Path;
}

/**
 * Represents unrecognized object.
 * Example is a broken symbolic link.
 */
interface Other {
  name: String;
  path: Path;
}

WorkspaceEdit

This is a message to be specified once we better understand the intricacies of undo/redo.

The actionables for this section are:

  • Work out the design of this message.
  • Specify this message.

EnsoDigest

A counterpart to SHA3-224 for the binary connection, this is a standard message digest encoded using FlatBuffers.

namespace org.enso.languageserver.protocol.binary;

table EnsoDigest {
  bytes : [ubyte] (required);
}

Notes:

  • It is an error for the length of the vector bytes to not be equal to 28 (224 / 8). This is the length of the chosen digest in bytes.

FileSegment

A representation of a segment of a file for use in the binary protocol.

namespace org.enso.languageserver.protocol.binary;

table FileSegment {
  // The file to access.
  path : Path (required);

  // The byte offset in the file to read from.
  byteOffset : ulong;

  // The number of bytes to read.
  length : ulong;
}

The byteOffset property is zero-indexed, so the last byte in the file is at index file.length - 1.

ContentRoot

A representation of a content root for use in the IDE. A content root represents a location on a real file-system that has been virtualised for use in the Enso VFS.

type ContentRoot = Project | FileSystemRoot | Home | Library | Custom;
/** This content root points to the project home. */
interface Project {
  // A unique identifier for the content root.
  id: UUID;
}

/**
 * This content root points to the system root (`/`) on unix systems, or to a
 * drive root on Windows. In Windows' case, there may be multiple `Root` entries
 * corresponding to the various drives.
 */
interface FileSystemRoot {
  // A unique identifier for the content root.
  id: UUID;

  // The absolute filesystem path of the content root.
  path: String;
}

/** The user's home directory. */
interface Home {
  // A unique identifier for the content root.
  id: UUID;
}

/** An Enso library location. */
interface Library {
  // A unique identifier for the content root.
  id: UUID;

  // The namespace of the library.
  namespace: String;

  // The name of the library.
  name: String;

  /**
   * The version of the library.
   *
   * It is either a semver version of the library or the string "local".
   */
  version: String;
}

/** A content root that has been added by the IDE (unused for now). */
interface Custom {
  // A unique identifier for the content root.
  id: UUID;
}

LibraryEntry

Represents a library available in a resolved edition.

interface LibraryEntry {
  namespace: String;
  name: String;
  version: LibraryVersion;
  isCached: Boolean;
}

LibraryVersion

Represents a library version, as returned in LibraryEntry.

type LibraryVersion = LocalLibraryVersion | PublishedLibraryVersion;

/** A library version that references a version of the library published in some
 * repository.
 */
interface PublishedLibraryVersion {
  // A semver-compliant version of the library.
  version: String;

  // URL to the repository that this library will be downloaded from.
  repositoryUrl: String;
}

// A library version that references a locally editable version of the library.
interface LocalLibraryVersion {}

Contact

Represents contact information of authors or maintainers.

Both fields are optional, but for the contact to be valid, at least one of them must be defined.

interface Contact {
  name?: String;
  email?: String;
}

EditionReference

A reference to a specific edition.

Currently, it can either reference an edition by its name, or reference the edition associated with the currently open project.

type EditionReference = NamedEdition | CurrentProjectEdition;

// The edition associated with the current project, with all of its overrides.
interface CurrentProjectEdition {}

// An edition stored under a given name.
interface NamedEdition {
  editionName: String;
}

Connection Management

In order to properly set-up and tear-down the language server connection, we need a set of messages to control this process.

session/initProtocolConnection

This message initialises the connection used to send the textual protocol messages. This initialisation is important such that the client identifier can be correlated between the textual and data connections.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  clientId: UUID;
}

Result

{
  contentRoots: [ContentRoot];
}

Errors

session/initBinaryConnection

This message initialises the data connection used for transferring binary data between engine and clients. This initialisation is important such that the client identifier can be correlated between the data and textual connections.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Data
  • Visibility: Public

Parameters

namespace org.enso.languageserver.protocol.binary;

//A command initializing a data session.
table InitSessionCommand {

  //A unique identifier of a client initializing the session.
  identifier: EnsoUUID (required);

}

root_type InitSessionCommand;

Result

namespace org.enso.languageserver.protocol.binary;

//Indicates an operation has succeeded.
table Success {}

Errors

N/A

Capability Management

In order to mediate between multiple clients properly, the language server has a robust notion of capability management to grant and remove permissions from clients.

capability/acquire

This requests that the server grant the specified capability to the requesting client.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  method: String;
  registerOptions?: any;
}

The registerOptions are determined by the method. The method must be listed in the section on capabilities below.

Result

null;

Errors

TBC

capability/release

This requests that the server acknowledge that the client is releasing a given capability.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  registration: CapabilityRegistration;
}

Result

null;

Errors

TBC

capability/granted

This notifies the client that it has been granted a capability without any action on its part.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  registration: CapabilityRegistration;
}

Errors

TBC

capability/forceReleased

This notifies the client that a capability has been forcibly removed from its capability set.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  registration: CapabilityRegistration;
}

Errors

TBC

Capabilities

The capability management features work with the following capabilities.

text/canEdit

This capability states that the capability has the ability to perform both text/applyEdit and text/save for the specified file.

  • method: text/canEdit
  • registerOptions: {path: Path;}

Enables

Disables

None

file/receivesTreeUpdates

This capability states that the client will receive updates for any watched content roots in the current project.

  • method: file/receivesTreeUpdates
  • registerOptions: { path: Path; }

Enables

Disables

None

Errors

capability/acquire:

capability/release:

executionContext/canModify

This capability states that the client has the ability to modify an execution context, including modifying the execution stack, invalidating caches, or destroying the context.

  • method: executionContext/canModify
  • registerOptions: { contextId: ContextId; }

Enables

Disables

None

executionContext/receivesUpdates

This capability states that the client receives expression value updates from a given execution context.

  • method: executionContext/receivesUpdates
  • registerOptions: { contextId: ContextId; }

Enables

Disables

None

search/receivesSuggestionsDatabaseUpdates

This capability states that the client receives the search database updates for a given execution context.

  • method: search/receivesSuggestionsDatabaseUpdates
  • registerOptions: {}

Enables

Disables

None

File Management Operations

The language server also provides file operations to the IDE.

file/write

This requests that the file manager component write to a specified file with the specified contents.

  • Type: Request
  • Direction: Client -> Server

This request is explicitly allowed to write to files that do not exist, and will create them under such circumstances. If a file is recorded as ‘open’ by one of the clients, and another client attempts to write to that file, the write must fail.

Parameters

{
  path: Path;
  contents: FileContents<T>;
}

Result

null;

Errors

file/read

This requests that the file manager component reads the contents of a specified file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

If the file is recorded as open by the language server, then the result will return the contents from the in-memory buffer rather than the file on disk.

Parameters

{
  path: Path;
}

Result

{
  contents: FileContents<T>;
}

Errors

file/writeBinary

This requests that the file manager component write to a specified file with the binary contents.

  • Type: Request
  • Connection: Binary
  • Direction: Client -> Server

This request is explicitly allowed to write to files that do not exist, and will create them under such circumstances. If a file is recorded as ‘open’ by one of the clients, and another client attempts to write to that file, the write must fail.

Parameters

namespace org.enso.languageserver.protocol.binary;

//A command writing binary contents to a file.
table WriteFileCommand {

  //A path to a file.
  path: Path;

  //Binary contents.
  contents: [ubyte];

}

Result

namespace org.enso.languageserver.protocol.binary;

//Indicates an operation has succeeded.
table Success {}

Errors

file/readBinary

This requests that the file manager component reads the binary contents of a specified file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Binary
  • Visibility: Public

If the file is recorded as open by the language server, then the result will return the contents from the in-memory buffer rather than the file on disk.

Parameters

namespace org.enso.languageserver.protocol.binary;

//A command reading binary contents from a file.
table ReadFileCommand {

  //A path to a file.
  path: Path;

}

Result

namespace org.enso.languageserver.protocol.binary;

//A reply for a ReadFileCommand.
table FileContentsReply {

  //Binary contents.
  contents: [ubyte];

}

Errors

file/writeBytes

This requests that the file manager component writes a set of bytes to the specified file at the specified offset.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Binary
  • Visibility: Public

This method will create a file if no file is present at path.

  • The overwriteExisting boolean should be set if byteOffset is less than the length of the file.
  • The byteOffset property is zero-indexed. To append to the file you begin writing at index file.length.
  • If byteOffset is less than the length of the file and overwriteExisting is set, it will truncate the file to length byteOffset + bytes.length.
  • If byteOffset > file.length, the bytes in the range [file.length, byteOffset) will be filled with null bytes. Please note that, in this case, the checksum in the response will also be calculated on the null bytes.

Parameters

namespace org.enso.languageserver.protocol.binary;

table WriteBytesCommand {
  // The file to write to.
  path : Path (required);

  // The byte offset in the file to write from.
  byteOffset : ulong;

  // Whether existing content should be overwritten.
  overwriteExisting : bool;

  // The file contents.
  bytes : [ubyte] (required);
}

Result

namespace org.enso.languageserver.protocol.binary;

table WriteBytesReply {
  // The checksum of the written bytes.
  checksum : EnsoDigest (required);
}

Notes:

  • The checksum is only of the bytes in the request as they were written to disk. This does not include checksumming the entire file. For that, please see file/checksumBytes.

Errors

  • CannotOverwrite to signal that an overwrite would be necessary to perform the operation but that overwriteExisting is not set.
  • NotFile if the provided segment.path is not a file.

file/readBytes

Asks the language server to read the specified number of bytes at the specified offset in the file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Binary
  • Visibility: Public

It will attempt to read as many as segment.length bytes, but does not guarantee that the response will contain segment.length bytes (e.g. if segment.length would require reading off the end of the file).

Parameters

namespace org.enso.languageserver.protocol.binary;

table ReadBytesCommand {
  // The segment in a file to read bytes from.
  segment : FileSegment (required);
}

Result

namespace org.enso.languageserver.protocol.binary;

table ReadBytesReply {
  // The checksum of the bytes in this response.
  checksum : EnsoDigest (required);

  // The requested file contents.
  bytes : [ubyte] (required);
}

Notes:

  • The checksum is of the bytes as they have been read from disk.

Errors

  • FileNotFound if the file at segment.path does not exist.
  • ReadOutOfBounds if segment.byteOffset is not present in the file at segment.path.
  • NotFile if the provided segment.path is not a file.

file/create

This request asks the file manager to create the specified file system object.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

This will fail if the specified object already exists.

Parameters

{
  object: FileSystemObject;
}

Response

null;

Errors

file/delete

This request asks the file manager to delete the specified file system object.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  path: Path;
}

Result

null

Errors

file/copy

This request asks the file manager to copy a specified filesystem object to another location.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  from: Path;
  to: Path;
}

Result

null;

Errors

file/move

This request asks the file manager to move a specified filesystem object to another location.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

The move should be specified by filesystem events, and such notifications should inform the client that the currently edited file has been moved.

Parameters

{
  from: Path;
  to: Path;
}

Result

null;

Errors

file/exists

This request asks the file manager to check whether a filesystem object exists at the specified path.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  path: Path;
}

Result

{
  exists: Boolean;
}

Errors

file/tree

This request asks the file manager component to generate and provide the directory tree starting at a given path.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  path: Path;
  depth?: Number;
}

Result

{
  tree: DirectoryTree;
}

Errors

file/list

This request lists the contents of a given filesystem object. For a file it will just return the file, while for a directory it will list the contents of the directory.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  path: Path;
}

Result

{
  paths: [FileSystemObject];
}

Errors

file/info

This request gets information about a specified filesystem object.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

This request should work for all kinds of filesystem object.

Parameters

{
  path: Path;
}

Result

{
  attributes: FileAttributes;
}

Errors

file/checksum

Requests that the language server provide the checksum of the provided file. Only defined when the provided path is a file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

It calculates the checksum of the entire file.

Parameters

interface ChecksumRequest {
  // The path to the file to get the checksum for.
  path: Path;
}

Result

interface ChecksumResponse {
  // The checksum of the file at `path`.
  checksum : SHA3-224;
}

Errors

  • FileNotFound if the file at path does not exist.
  • NotFile if the provided path does not point to a file.

file/checksumBytes

Requests that the language server provides the checksum of the provided byte range.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Binary
  • Visibility: Public

Parameters

namespace org.enso.languageserver.protocol.binary;

table ChecksumBytesCommand {
  // The segment in a file to checksum.
  segment : FileSegment (required);
}

Result

namespace org.enso.languageserver.protocol.binary;

table ChecksumBytesReply {
  // The segment in a file to checksum.
  checksum : EnsoDigest;
}

Errors

  • FileNotFound if the file at segment.path does not exist.
  • ReadOutOfBounds if segment.byteOffset is not present in the file at segment.path, or if segment.length does not fit within the file.
  • NotFile if the provided segment.path is not a file.

file/event

This is a notification that is sent every time something under a watched content root changes. It is used to ensure that the client’s filesystem representation stays in synchronisation with reality.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Events should be sent from server to client for every event observed under one of the (possibly multiple) content roots.

Parameters

{
  path: Path;
  kind: FileEventKind;
}

Errors

None

file/rootAdded

This is a notification sent to all clients to inform them that a content root has been added.

At the beginning, a series of notifications is sent that lists all content roots that are present at the current moment. This message may contain the same content roots that were already present in the session/initProtocolConnection. That is done, because there is no guarantee that no root has been added between the init message and the time when notifications start being sent, and this ensures that no content root is missed.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  root: ContentRoot;
}

Errors

TBC

file/rootRemoved

This is a notification sent to all clients other than the one performing the removal of the content root in order to inform them of the removal of the root.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  id: UUID; // The content root ID
}

Errors

TBC

Text Editing Operations

The language server also has a set of text editing operations to ensure that it stays in sync with the clients.

text/openFile

This requests the language server to open the specified file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

If no client has write lock on the opened file, the capability is granted to the client that sent the text/openFile message.

Parameters

{
  path: Path;
}

Result

{
  writeCapability?: CapabilityRegistration;
  content: String;
  currentVersion: SHA3-224;
}

Errors

text/closeFile

This requests the language server to close the specified file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  path: Path;
}

Result

null;

Errors

text/save

This requests for the language server to save the specified file.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

The request may fail if the requesting client does not have permission to edit that file, or if the client is requesting a save of an outdated version.

Parameters

{
  path: Path;
  currentVersion: SHA3 - 224;
}

Result

null;

Errors

text/applyEdit

This requests that the server apply a series of edits to the project. These edits solely concern text files.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

This operation may fail if the requesting client does not have permission to edit the resources for which edits are sent. This failure may be partial, in that some edits are applied and others are not.

Parameters

{
  edit: FileEdit;
}

Result

null;

Errors

text/didChange

This is a notification sent from the server to the clients to inform them of any changes made to files that they have open.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

This notification must only be sent for files that the client has open.

Parameters

{
  edits: [FileEdit];
}

Errors

null;

Workspace Operations

The language server also has a set of operations useful for managing the client workspace.

workspace/projectInfo

This request allows the IDE to request information about the currently open project in situations where it does not have a project manager to connect to.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
}

Result

{
  // The name of the project.
  projectName: String;

  // The engine version on which the project is running.
  engineVersion: String;

  // The version of graal on which the project is running.
  graalVersion: String;
}

Errors

  • CannotDecode if the project configuration cannot be decoded.
  • FileNotFound if the project configuration cannot be found.

workspace/undo

This request is sent from the client to the server to request that an operation be undone.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

The exact behaviour of this message is to be determined, but it must involve the server undoing that same action for all clients in the workspace.

Parameters

{
  requestID?: UUID; // If not specified, it undoes the latest request
}

Result

null;

Errors

TBC

workspace/redo

This request is sent from the client to the server to request that an operation be redone.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

The exact behaviour of this message is to be determined, but it must involve the server redoing that same action for all clients in the workspace.

Parameters

{
  requestID?: UUID; // If not specified, it redoes the latest request
}

Result

null;

Errors

TBC

Monitoring

The language server also has a heartbeat operation to monitor the Language server. This API is private and should be used only by the Project Manager.

heartbeat/ping

This request is sent from the supervisor process to the server to check the health of the Language Server.

  • Type: Request
  • Direction: Supervisor -> Server
  • Connection: Protocol
  • Visibility: Private

Parameters

null;

Result

null;

Errors

None

heartbeat/init

This request is sent from the bootloader to check if the started language server instance has finished initialization. A reply should only be sent when the main module has been fully initialized.

  • Type: Request
  • Direction: Supervisor -> Server
  • Connection: Protocol
  • Visibility: Private

Parameters

null;

Result

null;

Errors

None

Refactoring

The language server also provides refactoring operations to restructure an internal body of code.

refactoring/renameProject

This request is sent from the project manager to the server to refactor project name in an interpreter runtime.

  • Type: Request
  • Direction: Project Manager -> Server
  • Connection: Protocol
  • Visibility: Private

Parameters

{
  namespace: String;
  oldName: String;
  newName: String;
}

Result

null;

Errors

None

Execution Management Operations

The execution management portion of the language server API deals with exposing fine-grained control over program and expression execution to the clients of the language server. This is incredibly important for enabling the high levels of interactivity required by Enso Studio.

Execution Management Example

Given the default project structure.

├── package.yaml
└── src
    └── Main.enso
$ cat src/Main.enso

main =
    x = 6
    y = x.foo 5
    z = y + 5
    z

Number.foo = x ->
    y = this + 3
    z = y * x
    z



#### METADATA ####
[[{"index": {"value": 98}, "size": {"value": 5}}, "5fc0c11d-bd83-4ca3-b847-b8e362f7658c"],[{"index": {"value": 81}, "size": {"value": 8}}, "1cda3676-bd62-41f8-b6a1-a1e1b7c73d18"],[{"index": {"value": 42}, "size": {"value": 5}}, "899a11e5-4d2b-43dc-a867-2f2ef2d2ba62"],[{"index": {"value": 26}, "size": {"value": 7}}, "37f284d4-c593-4e65-a4be-4948fbd2adfb"],[{"index": {"value": 16}, "size": {"value": 1}}, "c553533e-a2b9-4305-9f12-b8fe7781f933"]]
[]

Notice extra newline in the beginning of the Main.enso file, it is important for the precalculated metadata indexes.

Create Execution Context

{
  "jsonrpc": "2.0",
  "method": "executionContext/create",
  "id": 0,
  "params": null
}

Return capabilities together with a newly created ContextId.

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": {
    "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3",
    "canModify": {
      "method": "executionContext/canModify",
      "registerOptions": {
        "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3"
      }
    },
    "receivesUpdates": {
      "method": "executionContext/receivesUpdates",
      "registerOptions": {
        "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3"
      }
    }
  }
}

Push Item

Entering the main method. First item on the stack should always be an ExplicitCall.

{
  "jsonrpc": "2.0",
  "method": "executionContext/push",
  "id": 0,
  "params": {
    "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3",
    "stackItem": {
      "type": "ExplicitCall",
      "methodPointer": {
        "file": {
          "rootId": "18f642a2-5f69-4fc8-add6-13bf199ca326",
          "segments": ["src", "Main.enso"]
        },
        "definedOnType": "Main",
        "name": "main"
      },
      "thisArgumentExpression": null,
      "positionalArgumentsExpressions": []
    }
  }
}

Returns successful reponse.

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": null
}

And a value update, result of the method foo call defined on type Number.

{
  "jsonrpc": "2.0",
  "method": "executionContext/expressionValuesComputed",
  "params": {
    "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3",
    "updates": [
      {
        "id": "37f284d4-c593-4e65-a4be-4948fbd2adfb",
        "type": "Number",
        "shortValue": "45",
        "methodCall": {
          "file": {
            "rootId": "18f642a2-5f69-4fc8-add6-13bf199ca326",
            "segments": ["src", "Main.enso"]
          },
          "definedOnType": "Number",
          "name": "foo"
        }
      }
    ]
  }
}

We can go deeper and evaluate the method foo call by pushing the LocalCall on the stack. In general, all consequent stack items should be LocalCalls.

{
  "jsonrpc": "2.0",
  "method": "executionContext/push",
  "id": 0,
  "params": {
    "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3",
    "stackItem": {
      "type": "LocalCall",
      "expressionId": "37f284d4-c593-4e65-a4be-4948fbd2adfb"
    }
  }
}

Returns successful reponse.

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": null
}

And update of some value inside the function foo.

{
  "jsonrpc": "2.0",
  "method": "executionContext/expressionValuesComputed",
  "params": {
    "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3",
    "updates": [
      {
        "id": "1cda3676-bd62-41f8-b6a1-a1e1b7c73d18",
        "type": "Number",
        "shortValue": "9",
        "methodCall": null
      }
    ]
  }
}

Pop Item

{
  "jsonrpc": "2.0",
  "method": "executionContext/pop",
  "id": 0,
  "params": {
    "contextId": "1eb5ad04-4094-4c1f-be54-e9d29ddf19a3"
  }
}

Popping one item will return us into the main method. Second call will clear the stack. Subsequent pop calls will result in an error indicating that the stack is empty.

executionContext/create

Sent from the client to the server to create a new execution context. Return capabilities executionContext/canModify and executionContext/receivesUpdates.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

{
  contextId: ContextId;
  canModify: CapabilityRegistration;
  receivesUpdates: CapabilityRegistration;
}

Errors

None

executionContext/destroy

Sent from the client to the server destroy an execution context and free its resources.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  contextId: ContextId;
}

Result

null;

Errors

executionContext/fork

Sent from the client to the server to duplicate an execution context, creating an independent copy, containing all the data precomputed in the first one. Return capabilities executionContext/canModify and executionContext/receivesUpdates.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  contextId: ContextId;
}

Result

{
  contextId: ContextId;
  canModify: CapabilityRegistration;
  receivesUpdates: CapabilityRegistration;
}

Errors

No known errors.

executionContext/push

Sent from the client to the server execute item and move the execution context to a new location deeper down the stack. If a stack item becomes invalid because of a text edit (e.g. the root function of the view was removed), it will stop executing. If the function reappears, execution should resume as normal.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  contextId: ContextId;
  stackItem: StackItem;
}

Result

null;

Errors

  • AccessDeniedError when the user does not hold the executionContext/canModify capability for this context.
  • StackItemNotFoundError when the request stack item could not be found.
  • InvalidStackItemError when pushing LocalCall on top of the empty stack, or pushing ExplicitCall on top of non-empty stack.

executionContext/pop

Sent from the client to the server move the execution context up the stack, corresponding to the client clicking out of the current breadcrumb.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  contextId: ContextId;
}

Result

null;

Errors

  • AccessDeniedError when the user does not hold the executionContext/canModify capability for this context.
  • EmptyStackError when the user tries to pop an empty stack.

executionContext/recompute

Sent from the client to the server to force recomputation of current position. May include a list of expressions for which caches should be invalidated.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  contextId: ContextId;
  invalidatedExpressions?: "all" | [ExpressionId]
}

Result

null;

Errors

  • AccessDeniedError when the user does not hold the executionContext/canModify capability for this context.
  • EmptyStackError when the user tries to recompute an empty stack.

executionContext/expressionUpdates

Sent from the server to the client to inform about new information for certain expressions becoming available. Supersedes the executionContext/expressionValuesComputed notification, that will be removed in future versions.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  contextId: ContextId;
  updates: [ExpressionUpdate];
}

Errors

None

executionContext/executionFailed

Sent from the server to the client to inform about a critical failure when attempting to execute a context.

When the executionContext/executionStatus notifies about potential problems in the code found by compiler, or the errors during runtime, this message signals about the errors in the logic or the implementation. It can be a compiler crash, an attempt to execute an empty stack, an error location a method or a module when issuing a executionContext/push command.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  /**
   * The identifier of the execution context.
   */
  contextId: ContextId;

  /**
   * The error message.
   */
  message: String;

  /**
   * The location of a file producing the error.
   */
  path?: Path;
}

Errors

None

executionContext/executionComplete

Sent from the server to the client to inform about the successful execution of a context.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  /** The identifier of the execution context. */
  contextId: ContextId;
}

Errors

None

executionContext/executionStatus

Sent from the server to the client to inform about a status of execution.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  /**
   * The identifier of the execution context.
   */
  contextId: ContextId;

  /**
   * The list of encountered problems.
   */
  diagnostics: Diagnostic[];
}

Errors

None

executionContext/executeExpression

This message allows the client to execute an arbitrary expression on a given node. It behaves like oneshot executionContext/attachVisualisation visualisation request, meaning that the visualisation expression will be executed only once.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

interface ExecuteExpressionRequest {
  visualisationId: UUID;
  expressionId: UUID;
  visualisationConfig: VisualisationConfiguration;
}

Result

null;

Errors

executionContext/attachVisualisation

This message allows the client to attach a visualisation, potentially preprocessed by some arbitrary Enso code, to a given node in the program.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

interface AttachVisualisationRequest {
  visualisationId: UUID;
  expressionId: UUID;
  visualisationConfig: VisualisationConfiguration;
}

Result

null;

Errors

executionContext/detachVisualisation

This message allows a client to detach a visualisation from the executing code.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

interface DetachVisualisationRequest {
  executionContextId: UUID;
  visualisationId: UUID;
  expressionId: UUID;
}

Result

null;

Errors

executionContext/modifyVisualisation

This message allows a client to modify the configuration for an existing visualisation.

A successful response means that the new visualization configuration has been applied. In case of an error response, the visualization state does not change.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

interface ModifyVisualisationRequest {
  visualisationId: UUID;
  visualisationConfig: VisualisationConfiguration;
}

Result

null;

Errors

executionContext/visualisationUpdate

This message is responsible for providing a visualisation data update to the client.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Data
  • Visibility: Public

The visualisationData component of the table definition must be pre-serialized before being inserted into this message. As far as this level of transport is concerned, it is just a binary blob.

Parameters

namespace org.enso.languageserver.protocol.binary;

//A visualisation context identifying a concrete visualisation.
table VisualisationContext {

  //A visualisation identifier.
  visualisationId: EnsoUUID (required);

  //A context identifier.
  contextId: EnsoUUID (required);

  //An expression identifier.
  expressionId: EnsoUUID (required);

}

//An event signaling visualisation update.
table VisualisationUpdate {

  //A visualisation context identifying a concrete visualisation.
  visualisationContext: VisualisationContext (required);

  //A visualisation data.
  data: [ubyte] (required);

}

root_type VisualisationUpdate;

Errors

N/A

executionContext/visualisationEvaluationFailed

Signals that an evaluation of a visualisation expression on the computed value has failed.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

interface VisualisationEvaluationFailed {
  /**
   * An execution context identifier.
   */
  contextId: ContextId;

  /**
   * A visualisation identifier.
   */
  visualisationId: UUID;

  /**
   * An identifier of a visualised expression.
   */
  expressionId: UUID;

  /**
   * An error message.
   */
  message: string;

  /**
   * Detailed information about the error.
   */
  diagnostic?: Diagnostic;
}

Errors

N/A

Search Operations

Search operations allow requesting for the autocomplete suggestions and search for the documentation. Search operations return links to the items in the Suggestions Database instead of returning full entries. Suggestions Database is a key-value storage with SuggestionEntry values.

Suggestions Database Example

The following code snippet shows examples of the database entries.

type MyType a b

type Maybe
    Nothing
    Just a

    is_just = case this of
        Just _  -> true
        Nothing -> false

foo x =
    10 - x

Number.baz x =
    this + x * 10

main =
    x = foo 42
    y = x.baz x
    IO.println y

MyType

<SuggestionEntryAtom>{
  name: "MyType",
  arguments: [],
  returnType: "MyType",
};

Maybe.Nothing

<SuggestionEntryAtom>{
  name: "Nothing",
  arguments: [],
  returnType: "Maybe",
};

Maybe.Just

<SuggestionEntryAtom>{
  name: "Just",
  arguments: [
    {
      name: "a",
      type: "Any",
      isSuspended: false,
      hasDefault: false,
    },
  ],
  returnType: "Maybe",
};

Maybe.is_just

<SuggestionEntryMethod>{
  name: "is_just",
  arguments: [],
  selfType: "Maybe",
  returnType: "Bool",
};

foo

<SuggestionEntryFunction>{
  name: "foo",
  arguments: [
    {
      name: "x",
      type: "Number",
      isSuspended: false,
      hasDefault: false,
    },
  ],
  returnType: "Bool",
};

Number.baz

<SuggestionEntryMethod>{
  name: "baz",
  arguments: [
    {
      name: "x",
      type: "Number",
      isSuspended: false,
      hasDefault: false,
    },
  ],
  selfType: "Number",
  returnType: "Number",
};

Local x

<SuggestionEntryLocal>{
  name: "x",
  returnType: "Number",
};

Local y

<SuggestionEntryLocal>{
  name: "y",
  returnType: "Number",
};

search/getSuggestionsDatabase

Sent from client to the server to receive the full suggestions database.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

{
  // The list of suggestions database entries
  entries: [SuggestionsDatabaseEntry];
  // The version of received suggestions database
  currentVersion: number;
}

Errors

search/invalidateSuggestionsDatabase

Sent from client to the server to clean the suggestions database resetting the version.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

null;

Errors

search/getSuggestionsDatabaseVersion

Sent from client to the server to receive the current version of the suggestions database.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

{
  // The version of the suggestions database
  currentVersion: number;
}

Errors

search/suggestionsDatabaseUpdate

Sent from server to the client to inform abouth the change in the suggestions database.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  updates: [SuggestionsDatabaseUpdate];
  currentVersion: number;
}

Errors

None

search/suggestionsOrderDatabaseUpdate

Sent from server to the client to inform abouth the change in the suggestions order database.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  updates: [SuggestionsOrderDatabaseUpdate];
}

Errors

None

search/completion

Sent from client to the server to receive the autocomplete suggestion.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  // The edited file
  file: Path;
  // The cursor position
  position: Position;
  // Filter by methods with the provided self type
  selfType?: string;
  // Filter by the return type
  returnType?: string;
  // Filter by the suggestion types
  tags?: [SuggestionEntryType];
}

Result

The identifiers in results are guaranteed to be ordered by the specificity of the type match.

{
  results: [SuggestionId];
  currentVersion: number;
}

Errors

search/import

Sent from client to the server to receive the information required for module import.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  /**
   * The id of suggestion to import.
   */
  id: SuggestionId;
}

Result

{
  /**
   * The definition module of the suggestion.
   */
  module: String;

  /**
   * The name of the resolved suggestion.
   */
  symbol: String;

  /**
   * The list of modules that re-export the suggestion. Modules are ordered
   * from the least to most nested.
   */
  exports: Export[];
}

Errors

Input/Output Operations

The input/output portion of the language server API deals with redirecting stdin/stdout/stderr of Enso programs to the clients of the language server. This is incredibly important for enabling the high levels of interactivity required by Enso Studio.

io/redirectStandardOutput

This message allows a client to redirect the standard output of Enso programs. Once the standard output is redirected, the Language server will notify the client about new output data by emitting io/standardOutputAppended messages.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

null;

Errors

N/A

io/suppressStandardOutput

This message allows a client to suppress the redirection of the standard output.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

null;

Errors

N/A

io/standardOutputAppended

Sent from the server to the client to inform that new output data are available for the standard output.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  output: String;
}

io/redirectStandardError

This message allows a client to redirect the standard error of Enso programs. Once the standard error is redirected, the Language server will notify the client about new output data by emitting io/standardErrorAppended messages.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

null;

Errors

N/A

io/suppressStandardError

This message allows a client to suppress the redirection of the standard error.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

Result

null;

Errors

N/A

io/standardErrorAppended

Sent from the server to the client to inform that new output data are available for the standard error.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  output: String;
}

io/feedStandardInput

This message allows a client to feed the standard input of Enso programs.

  • Type: Request
  • Direction: Client -> Server
  • Connection: Protocol
  • Visibility: Public

Parameters

{
  input: String;
  isLineTerminated: Boolean;
}

Result

null;

Errors

N/A

io/waitingForStandardInput

Sent from the server to the client to inform that an Enso program is suspended by IO.readln. This message is used to notify a client that she should feed the standard input.

  • Type: Notification
  • Direction: Server -> Client
  • Connection: Protocol
  • Visibility: Public

Parameters

null;

The library-related operations provide the Language Server with capabilities to check and modify project’s edition settings, list editions published in a given edition, create local library projects which can be imported in the currently opened project and publish them.

editions/listAvailable

Lists editions available on the system.

Moreover, if update is set to true, it will download any new editions from the repositories and include them in the result as well.

Currently, if update was true but some downloads failed, the endpoint will still return a success, just containing the editions that were already available. In the future it should emit warnings using proper notification channels.

Parameters

{
  update: Boolean;
}

Result

{
  editionNames: [String];
}

editions/resolve

Resolves settings implied by the edition.

Currently, it only resolves the engine version, as only it is needed, but other settings may be added if necessary.

Parameters

{
  edition: EditionReference;
}

Result

{
  engineVersion: String;
}

Errors

  • EditionNotFoundError indicates that the requested edition, or some edition referenced in the ancestors of the edition being resolved, could not be found.
  • FileSystemError to signal a generic, unrecoverable file-system error.

editions/getProjectSettings

Returns the currently set edition-related settings of the project.

Currently, it only returns the parent edition and local library preference. Once more advanced edition settings are to be supported in the IDE, this endpoint will be extended.

Parameters

null;

Result

{
    parentEdition?: String;
    preferLocalLibraries: Boolean;
}

The parentEdition may be missing if it is not set. It is possible to manually edit the pacakge.yaml and generate a valid edition config that does not specify a parent edition.

editions/setProjectParentEdition

Sets the parent edition of the project to a specific edition.

This change may even change the version of the engine associated with the project, so for the changes to take effect, the language server may need to be restarted. The endpoint only modifies the pacakge.yaml file, which is preloaded in the Language Server, so it is IDE’s responsibility to re-open the project.

It returns an optional field needsRestart which specifies whether the Language Server needs to be restarted for the change to take effect. If the field is missing, it should be treated as set to false. In the current version it is always set to true.

Parameters

{
  newEditionName: String;
}

Result

{
    needsRestart?: Boolean;
}

Errors

editions/setProjectLocalLibrariesPreference

Sets the prefer-local-libraries setting of the project, which specifies if libraries from ENSO_HOME/libraries should take precedence over the ones defined in the edition.

This may change which libraries should be loaded in the project. In the future it may be possible that this reload could happen dynamically, however currently, the language server needs to be restarted (in the same way as for editions/setProjectParentEdition) for the changes to take effect.

It returns an optional field needsRestart which specifies whether the Language Server needs to be restarted for the change to take effect. If the field is missing, it should be treated as set to false. In the current version it is always set to true.

Parameters

{
  preferLocalLibraries: Boolean;
}

Result

{
    needsRestart?: Boolean;
}

Errors

editions/listDefinedLibraries

Lists all libraries defined in an edition (or all of its parents).

This can be used to display which libraries can be downloaded / added to the project.

This does not include local libraries not defined explicitly in the project’s edition, even if they can be resolved as per prefer-local-libraries setting. To get local libraries that are not directly referenced in the edition, use library/listLocal instead.

Parameters

{
  edition: EditionReference;
}

Result

{
  availableLibraries: [LibraryEntry];
}

Errors

  • EditionNotFoundError indicates that the requested edition, or an edition referenced in one of its parents, could not be found.
  • FileSystemError to signal a generic, unrecoverable file-system error.

library/listLocal

Lists all local libraries available in the system.

Parameters

null;

Result

{
  localLibraries: [LibraryEntry];
}

Errors

library/create

Creates a new project package, but placed not in the projects directory, but in the local libraries directory, so that other projects (including the current one) that can resolve local libraries will be able to import it.

The created library package inherits all edition settings from the current project.

The endpoint just returns an empty message at success. Once this operation finishes, the IDE can add the import import <namespace>.<name> to the open file which will import the newly created library (the IDE must also ensure that prefer-local-libraries is set to true or otherwise, it must add a proper override to its own edition file to see this local library). Once the import is added, the library will be loaded and its content root will be sent in a file/rootAdded notification.

Parameters

{
  namespace: String;
  name: String;
  authors: [Contact];
  maintainers: [Contact];
  license: String;
}

Result

null;

Errors

library/getMetadata

Gets metadata associated with a specific library version.

If the version is LocalLibraryVersion, it will try to read the manifest file of the local library and return an empty result if the manifest does not exist.

If the version is PublishedLibraryVersion, it will fetch the manifest from the library repository. A cached manifest may also be used, if it is available.

All returned fields are optional, as they may be missing.

Parameters

{
  namespace: String;
  name: String;
  version: LibraryVersion;
}

Results

{
  description?: String;
  tagLine?: String;
}

Errors

  • LocalLibraryNotFound to signal that a local library with the given name does not exist on the local libraries path.
  • FileSystemError to signal a generic, unrecoverable file-system error.

library/setMetadata

Sets metadata associated with a local library that will be used for publishing.

All metadata fields are optional. If a field is not set in the parameters, it will be removed from the metadata (if it was present before).

Parameters

{
  namespace: String;
  name: String;
  description?: String;
  tagLine?: String;
}

Results

null;

Errors

  • LocalLibraryNotFound to signal that a local library with the given name does not exist on the local libraries path.
  • FileSystemError to signal a generic, unrecoverable file-system error.

library/publish

Publishes a library located in the local libraries directory to the main Enso library repository.

If bumpVersionAfterPublish is set to true, after publishing the library, its version is bumped automatically, so that future publications will not clash versions. This is a temporary solution and in the longer-term it should be replaced with separate settings allowing to arbitrarily modify the library version from the IDE.

The uploadUrl is the URL of the library repository that accepts library uploads.

The metadata for publishing the library can be set with library/setMetadata. If it was not set, the publish operation will still proceed, but that metadata will be missing.

Parameters

{
  namespace: String;
  name: String;
  authToken: String;
  uploadUrl: String;

  bumpVersionAfterPublish?: Boolean;
}

Result

null;

Errors

library/preinstall

Ensures that the requested library and all of its (transitive) dependencies, at versions as resolved by the current project’s edition, are downloaded.

Once this operation completes, the library import can be added to the project and it is guaranteed that (unless there were unexpected changes to the system, like files being manually deleted) no further downloads will be needed, so that the import should load quickly.

This can be used by the IDE to predownload the library that is about to be added to a project, to avoid freezing the compiler for the time the dependencies are being downloaded.

While this operation is in progress, multiple series of task/* notifications may be sent, indicating progress of particular components being downloaded and installed.

Parameters

{
  namespace: String;
  name: String;
}

Result

null;

Errors

  • LibraryNotResolved to signal that the requested library or one of its dependencies could not be resolved.
  • LibraryDownloadError to signal that the download operation has failed, for network-related reasons, or because the library was missing in the repository. The error includes the name and version of the library that failed to download - as when preinstalling a specific library the failure may be tied not to that library itself but also one of its dependencies.
  • FileSystemError to signal a generic, unrecoverable file-system error.

Errors

The language server component also has its own set of errors. This section is not a complete specification and will be updated as new errors are added.

Besides the required code and message fields, the errors may have a data field which can store additional error-specific payload.

Error

An error container for the binary connection that contains a code, message and payload.

namespace org.enso.languageserver.protocol.binary;

table Error {
  // A unique error code identifying error type.
  code: int;

  // An error message.
  message: string (required);

  // Additional payloads for the error.
  data : ErrorPayload;
}

union ErrorPayload {
  ...
}

Note:

  • The union ErrorPayload will be extended with additional payloads as necessary.
  • All textual-protocol errors can be represented using this structure.

AccessDeniedError

It signals that a user doesn’t have access to a resource.

"error" : {
  "code" : 100,
  "message" : "Access denied"
}

FileSystemError

This error signals generic file system errors.

"error" : {
  "code" : 1000,
  "message" : String
}

ContentRootNotFoundError

The error informs that the requested content root cannot be found.

"error" : {
  "code" : 1001,
  "message" : "Content root not found"
}

FileNotFound

It signals that requested file doesn’t exist.

"error" : {
  "code" : 1003,
  "message" : "File not found"
}

FileExists

It signals that file already exists.

"error" : {
  "code" : 1004,
  "message" : "File already exists"
}

OperationTimeoutError

It signals that IO operation timed out.

"error" : {
  "code" : 1005,
  "message" : "IO operation timeout"
}

NotDirectory

It signals that provided path is not a directory.

"error" : {
  "code" : 1006,
  "message" : "Path is not a directory"
}

NotFile

It signals that the provided path is not a file.

"error" : {
  "code" : 1007,
  "message" : "Path is not a file"
}

CannotOverwrite

Signals that a streaming file write cannot overwrite a portion of the requested file.

"error" : {
  "code" : 1008,
  "message" : "Cannot overwrite the file without `overwriteExisting` set"
}

ReadOutOfBounds

Signals that the requested file read was out of bounds for the file’s size.

"error" : {
  "code" : 1009
  "message" : "Read is out of bounds for the file"
  "data" : {
    "fileLength" : 0
  }
}

CannotDecode

Signals that the project configuration cannot be decoded.

"error" : {
  "code" : 1010
  "message" : "Cannot decode the project configuration"
}
namespace org.enso.languageserver.protocol.binary;

table ReadOutOfBoundsError {
  // The actual length of the file.
  fileLength : ulong (required);
}

StackItemNotFoundError

It signals that provided stack item was not found.

"error" : {
  "code" : 2001,
  "message" : "Stack item not found"
}

ContextNotFoundError

It signals that provided context was not found.

"error" : {
  "code" : 2002,
  "message" : "Context not found"
}

EmptyStackError

It signals that stack is empty.

"error" : {
  "code" : 2003,
  "message" : "Stack is empty"
}

InvalidStackItemError

It signals that stack is invalid in this context.

"error" : {
  "code" : 2004,
  "message" : "Invalid stack item"
}

ModuleNotFoundError

It signals that the given module cannot be found.

"error" : {
  "code" : 2005,
  "message" : "Module not found [Foo.Bar.Baz]"
}

VisualisationNotFoundError

It signals that the visualisation cannot be found.

"error" : {
  "code" : 2006,
  "message" : "Visualisation not found"
}

VisualisationExpressionError

It signals that the expression specified in the VisualisationConfiguration cannot be evaluated. The error contains an optional data field of type Diagnostic providing error details.

"error" : {
  "code" : 2007,
  "message" : "Evaluation of the visualisation expression failed [i is not defined]"
  "data" : {
    "kind" : "Error",
    "message" : "i is not defined",
    "path" : null,
    "location" : {
      "start" : {
        "line" : 0,
        "character" : 8
      },
      "end" : {
        "line" : 0,
        "character" : 9
      }
    },
    "expressionId" : "aa1f75c4-8c4d-493d-a6a7-72123a52f084",
    "stack" : []
  }
}

FileNotOpenedError

Signals that a file wasn’t opened.

"error" : {
  "code" : 3001,
  "message" : "File not opened"
}

TextEditValidationError

Signals that validation has failed for a series of edits.

"error" : {
  "code" : 3002,
  "message" : "The start position is after the end position"
}

InvalidVersionError

Signals that version provided by a client doesn’t match to the version computed by the server.

"error" : {
  "code" : 3003,
  "message" : "Invalid version [client version: ade2967cab172183d1a67ea40cb8e92e23218764bc9934c3795fcea5, server version: 7602967cab172183d1a67ea40cb8e92e23218764bc9934c3795fcea5]"
}

WriteDeniedError

Signals that the client doesn’t hold write lock to the buffer.

"error" : {
  "code" : 3004,
  "message" : "Write denied"
}

CapabilityNotAcquired

Signals that requested capability is not acquired.

"error" : {
  "code" : 5001,
  "message" : "Capability not acquired"
}

SessionNotInitialisedError

Signals that requested cannot be proccessed, beacuse session is not initialised.

"error" : {
  "code" : 6001,
  "message" : "Session not initialised"
}

SessionAlreadyInitialisedError

Signals that session is already initialised.

"error" : {
  "code" : 6002,
  "message" : "Session already initialised"
}

ResourcesInitializationError

Signals about the failure in the Language Server initialization process.

"error" : {
  "code" : 6003,
  "message" : "Failed to initialize the Language Server resources"
}

SuggestionsDatabaseError

Signals about an error accessing the suggestions database.

"error" : {
  "code" : 7001,
  "message" : "Suggestions database error"
}

ProjectNotFoundError

Signals that the project not found in the root directory.

"error" : {
  "code" : 7002,
  "message" : "Project not found in the root directory"
}

ModuleNameNotResolvedError

Signals that the module name can not be resolved for the given file.

"error" : {
  "code" : 7003,
  "message" : "Module name can't be resolved for the given file"
}

SuggestionNotFoundError

Signals that the requested suggestion was not found.

"error" : {
  "code" : 7004,
  "message" : "Requested suggestion was not found"
}

EditionNotFoundError

Signals that an edition could not be found.

Its payload includes the name of the edition that could not be found.

"error" : {
  "code" : 8001,
  "message" : "Edition [<name>] could not be found.",
  "payload" : {
    "editionName": "<name>"
  }
}

LibraryAlreadyExists

Signals that a local library with the specified namespace and name combination already exists, so it cannot be created again.

"error" : {
  "code" : 8002,
  "message" : "Library [<namespace>.<name>] already exists."
}

LibraryRepositoryAuthenticationError

Signals that authentication to the library repository was declined.

"error" : {
  "code" : 8003,
  "message" : "Authentication failed: [message]"
}

LibraryPublishError

Signals that a request to the library repository failed.

"error" : {
  "code" : 8004,
  "message" : "Could not publish the library: [message]"
}

LibraryUploadError

Signals that uploading the library failed for network-related reasons.

"error" : {
  "code" : 8005,
  "message" : "Could not upload the library: [message]"
}

LibraryDownloadError

Signals that downloading the library failed for network-related reasons or that it was not available in the repository.

"error" : {
  "code" : 8006,
  "message" : "Could not download the library: [message]",
  "payload" : {
    "namespace" : "<namespace>",
    "name" : "<name>",
    "version": "<version>"
  }
}

LocalLibraryNotFound

Signals that a local library with the specified namespace and name combination was not found on the local libraries path.

"error" : {
  "code" : 8007,
  "message" : "Local library [<namespace>.<name>] has not been found."
}

LibraryNotResolved

Signals that a library could not be resolved - it was not defined in the edition and the settings did not allow to resolve local libraries or it did not exist there either.

"error" : {
  "code" : 8008,
  "message" : "Could not resolve [<namespace>.<name>].",
  "payload" : {
    "namespace" : "<namespace>",
    "name" : "<name>"
  }
}

InvalidLibraryName

Signals that the chosen library name is invalid.

It contains a suggestion of a similar name that is valid.

For example for FooBar it will suggest Foo_Bar.

"error" : {
  "code" : 8009,
  "message" : "[<name>] is not a valid name: <reason>.",
  "payload" : {
    "suggestedName" : "<fixed-name>"
  }
}