This repository provides a Vim plugin to automate replacing expressions with assigned variables in multiple programming language.

An animated Gif is worth a 1,000 words:

In many programming languages, a common editing operation is to move subexpressions out of a nested expression into their own assigned names.

To illustrate, suppose we want to transform the following:

call_func(some_code, some_complex_and_long_expression);

Into the following:

let var = some_complex_and_long_expression;
...
call_func(some_code, var);

There can be any amount of lines between the top expression and the variable assignment.

The plugin supports the following languages: Rust, C, C++, Go, VimScript, JavaScript, TypeScript, Python, LISP, Scheme, Racket, Clojure, Erlang, Elixir, Haskell and PureScript.

First, note that the default kbd combination is Alt - =, and it is bound in visual mode.

Each usage has four steps:

• Mark the expression to replace with a visual selection.
• Hit the key combination, pick the name of the expression.
• Now in 'placement mode', move the assignment expression with Up or Down, or using k or j.
• End placing the assignment with Esc or Return.

The trigger to activate can be set to a different key:

vmap <leader>b <Plug>NameAssign

It is also possible to override mappings done for the placement mode to different keys, for example:

let g:name_assign_mode_maps = { "up" : ["n"],  "down" : ["N"] }

These mappings are temporary and buffer local, so they will not affect any global mappings for the specified keys.

Here's the full list of actions:

• up : For moving the placement up
• down : For moving the placement down
• settle : For ending placement

• Extend support to more languages.
• Allow to customize the content of the @ register after the operation. Currently it will contain the entered name.
• Don't liter the undo history too much with the movement, or try to rely on vim-schlepp that probably does it better.