comapny-symbol-after-symbol / complete-symbol-after-symbol

WIP: Simple-minded omni completion for company / completion-at-point

(require 'company-symbol-after-symbol)
(push 'company-symbol-after-symbol company-backends)

implementation

BOL 2-gram completion

example (consider "|" as the cursor):

FooComponent.propTypes = {
  foo: PropTypes.bool.isRequired,
  bar: PropTypes.func,
  baz: PropTypes.arrayOf(PropTypes.number)
}

...

BarComponent.propTypes = {
  foo: |
}

Here we have foo: , which is the first word in the line, before the cursor. Then company-symbol-after-symbol searches for ^\\W*foo: through the buffer, and finds the following snippet.

  foo: PropTypes

So company-symbol-after-symbol completes PropTypes here.

BarComponent.propTypes = {
  foo: PropTypes|
}

3-gram completion

Now we have two words before the cursor.

BarComponent.propTypes = {
  foo: PropTypes.|
}

Then company-symbol-after-symbol searches for foo: PropTypes. through the buffer and finds the following snippet.

foo: PropTypes.bool

So company-symbol-after-symbol completes bool here.

BarComponent.propTypes = {
  foo: PropTypes.bool|
}

2-gram completion

Consider the following situation:

BarComponent.propTypes = {
  foo: PropTypes.bool,
  qux: PropTypes.|
}

Here company-symbol-after-symbol first searches for qux: PropTypes., which finds nothing. Then company-symbol-after-symbol falls back to "2-gram" completion. company-symbol-after-symbol shorten the query to PropTypes. and finds following snippets.

PropTypes.bool
PropTypes.func
PropTypes.arrayOf

So company-symbol-after-symbol shows three completion candidates (bool, func, arrayOf) and completes the selected one.

Note that this fallbac behavior may give less accurate candidates than other two methods. So this can be disabled by setting company-symbol-after-symbol-fallback-to-2gram to nil.

symbols from other buffers

company-symbol-after-symbol can also complete symbols from other buffers in the same major-mode.

Internally, company-symbol-after-symbol caches symbols in inactive buffers into an efficient data structure called radix-tree, so that company-symbol-after-symbol can find completion candidates efficiently.