Version 0.15.0 has been released on 2021-01-30, 6 months after 0.14.0, bringing many new features and bugfixes.

As usual, prebuilt binaries are offered for most common platforms.

Breaking changes

Builtin functions and subnamespaces of edit: are now read-only.
Introspection for rest arguments has changed:
- The rest argument is now contained in the arg-names field of a closure.
- The rest-arg field now contains the index of the rest argument, instead of the name.
The -source command now runs in a temporary namespace and can no longer affect the local scope of its caller.
Key modifiers are no longer case insensitive. For example, Alt is still recognized but alt is not. This makes key modifier parsing consistent with key names. See #1163.

Deprecated features

Deprecated features will be removed in 0.16.0.

The following deprecated features trigger a warning whenever the code is parsed or compiled, even if it is not executed:

Using the syntax of temporary assignment (var=value) for non-temporary assignment is now deprecated. The syntax is still valid for temporary assignment. For example, using foo=bar as a standalone command is deprecated, but using it as part of command, like foo=bar ls, is not deprecated.
The chr command is now deprecated. Use str:from-codepoints instead.
The ord command is now deprecated. Use str:to-codepoints instead.
The has-prefix command is now deprecated. Use str:has-prefix instead.
The has-suffix command is now deprecated. Use str:has-suffix instead.
The -source command is now deprecated. Use eval instead.
The undocumented esleep command is now deprecated. Use sleep instead.
The eval-symlinks command is deprecated. Use path:eval-symlinks instead.
The path-abs command is deprecated. Use path:abs instead.
The path-base command is deprecated. Use path:base instead.
The path-clean command is deprecated. Use path:clean instead.
The path-dir command is deprecated. Use path:dir instead.
The path-ext command is deprecated. Use path:ext instead.
The -is-dir command is deprecated. Use path:is-dir instead.

The following deprecated features trigger a warning when the code is evaluated:

Using : in slice indices is deprecated. Use .. instead.
The mechanism of assigning to $-exports- in rc.elv to export variables to the REPL namespace is deprecated. Use edit:add-vars instead.

New features in the language:

A new var special command can be used to explicitly declare variables, and optionally assign them initial values.
A new set special command can be used to set the values of variables or elements.
Slice indices can now use .. for left-closed, right-open ranges, and ..= for closed ranges.
Rest variables and rest arguments are no longer restricted to the last variable.
Variables containing any character can now be assigned and used by quoting their name, for example 'name!' = foo; put $'name!'.

New features in the standard library:

A new eval command supports evaluating a dynamic piece of code in a restricted namespace.
A new sleep command.
A new path: module has been introduced for manipulating and testing filesystem paths.
A new deprecate command.

New features in the interactive editor:

The new commands edit:add-var and edit:add-vars provide an API for manipulating the REPL’s namespace from anywhere.
SGR escape sequences written from the prompt callback are now supported.

New features in the main program:

When using -compileonly to check Elvish sources that contain parse errors, Elvish will still try to compile the source code and print out compilation errors.