The purpose of this project is to modernize and augment the many custom JavaScript Patterns for Exuberant Ctags that have been floating the web for years.
We want to make sure Exuberant Ctags doesn't miss a single named symbol in our whole code base and do so without unnecessary duplication:
- Tags,
- Array literals,
- Object literals,
- Object properties,
- Generator functions,
- Free-form functions,
- Constructors and classes,
- Methods,
- Variables,
- Named imports,
- Named exports,
- Styled components
This is done by disabling the default "kinds", creating new ones, and crafting as many patterns as necessary.
These patterns are only usable with Exuberant Ctags. Universal Ctags is not currently supported.
Note about disabling the default "kinds".
The option --javascript-kinds=-c-f-m-p-v in ctagsrc will disable the default kinds, c (classes), f (functions), m (methods), p (properties), and v (global variables), for JavaScript files.
This means your ctags program's builtin regex patterns or any user defined patterns registered against these kinds will no longer function and the patterns defined in ctagsrc will be the only patterns active for the JavaScript language.
This is done to have a single source of patterns and avoid duplicated tags.
-
Clone this repository:
$ cd ~/my/cool/stuff $ git clone https://github.com/romainl/ctags-patterns-for-javascript.git -
Make sure you don't have a
~/.ctagsfile. -
Build a
tagsfile against the providedindex.js:$ cd ~/my/cool/stuff/ctags-patterns-for-javascript $ make tags
-
Clone this repository:
$ cd ~/my/cool/stuff $ git clone https://github.com/romainl/ctags-patterns-for-javascript.git -
In your shell, run the following command to tell Exuberant Ctags to use the options defined in the provided
ctagsrcfile:$ echo "--options=~/my/cool/stuff/ctags-patterns-for-javascript/ctagsrc" >> ~/.ctagswith
~/my/cool/stuff/ctags-patterns-for-javascript/ctagsrcbeing your actual path, of course. -
Use this command to generate a
tagsfile at the root of your JavaScript project:$ ctags -R .
If for some reason the above instructions sound like Klingon to you, just copy the content of this file and paste it into your own ~/.ctags file. If that file doesn't exist, create it.
--regex-javascript=/\/\/[ \t]*\(FIXME\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(TODO\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(BUG\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(NOBUG\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(???\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(!!!\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(HACK\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
--regex-javascript=/\/\/[ \t]*\(XXX\)[ \t]*:*\(.*\)/\1/T,Tag,Tags/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
// FIXME: fix non-working Patterns | FIXME | T
// TODO: better ES6+ support | TODO | T
// BUG: there's really something fishy about this | BUG | T
// ???: what the flying fuck? | ??? | T
// !!!: dear god! | !!! | T
// HACK: deployment is in 15 minutes | HACK | T
// XXX: I. Must. Finish. That. Mess. Quickly. | XXX | T
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*\[/\1/A,Array,Arrays/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*\[/\1/A,Array,Arrays/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*\[/\1/A,Array,Arrays/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
let array_name = [... | array_name | A
var array_name = [... | array_name | A
const array_name = [... | array_name | A
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*[{]/\1/O,Object,Objects/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*[{]/\1/O,Object,Objects/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*[{]/\1/O,Object,Objects/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
let object_name = {... | object_name | O
var object_name = {... | object_name | O
const object_name = {... | object_name | O
--regex-javascript=/^[ \t]*\(this\.\)*\([A-Za-z0-9_$]\{1,\}\)[ \t]*[:=].*[,;]*[^{]$/\2/P,Property,Properties/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
foo: 123, | foo | P
foo: 123 | foo | P
bar : "eee", | bar | P
bar : "eee" | bar | P
baz : /regexp/, | baz | P
baz : /regexp/ | baz | P
TODO:
var obj_lit_inline = { prop_qux: 1 };
--regex-javascript=/^[ \t]*function[ \t]*\*[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\1/G,Generator,Generators/b
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function\([ \t]*\*\)/\1/G,Generator,Generators/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function\([ \t]*\*\)/\1/G,Generator,Generators/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function\([ \t]*\*\)/\1/G,Generator,Generators/b
--regex-javascript=/^[ \t]*\(\*[ \t]\)\([A-Za-z0-9_$]\{1,\}\)[ \t]*(.*)[ \t]*[{]/\2/G,Generator,Generators/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
function* generator_name() {... | generator_name | G
function *generator_name() {... | generator_name | G
function * generator_name() {... | generator_name | G
function*generator_name() {... | generator_name | G
const generator_name = function* () {... | generator_name | G
const generator_name = function * () {... | generator_name | G
* generator_name() {... | generator_name | G
--regex-javascript=/^[ \t]*function[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t(]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*[(]function[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t(]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function[^\*][^\*]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function[^\*][^\*]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function[^\*][^\*]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*([^\*]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*([^\*]/\1/F,Function,Functions/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([a-z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*([^\*]/\1/F,Function,Functions/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
function func_name() {... | func_name | F
(function func_name() {... | func_name | F
var func_name = function() {... | func_name | F
let func_name = function() {... | func_name | F
const func_name = function() {... | func_name | F
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function/\1/C,Class,Classes/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function/\1/C,Class,Classes/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Z][A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*function/\1/C,Class,Classes/b
--regex-javascript=/^[ \t]*class[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/C,Class,Classes/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
class ClassName {... | ClassName | C
var Constructor = function() {... | Constructor | C
--regex-javascript=/^[ \t]*this\.\([A-Za-z0-9_$]\{1,\}\)[ \t]*=.*[{]$/\1/M,Method,Methods/b
--regex-javascript=/^[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*[:=][ \t]*[(]*function[ \t]*(/\1/M,Method,Methods/b
--regex-javascript=/^[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*[=][ \t].\{1,\}=>/\1/M,Method,Methods/b
--regex-javascript=/^[ \t]*static[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*(/\1/M,Method,Methods/b
--regex-javascript=/^[ \t]*\([A-Za-z0-9_$]\{1,\}\)(.*)[ \t]*[{]/\1/M,Method,Methods/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
this.method_name = function() {... | method_name | M
method_name : function() {... | method_name | M
static method_name() {... | method_name | M
method_name() {... | method_name | M
method_name = (param) => ... | method_name | M
method_name = param => ... | method_name | M
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*[0-9\"'\/]/\1/V,Variable,Variables/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*[0-9\"'\/]/\1/V,Variable,Variables/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*[0-9\"'\/]/\1/V,Variable,Variables/b
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*new/\1/V,Variable,Variables/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*new/\1/V,Variable,Variables/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*new/\1/V,Variable,Variables/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
const var_name = 1; | var_name | V
var var_name = /regexp/; | var_name | V
let var_name = 'foo'; | var_name | V
let var_name = "bar"; | var_name | V
let var_name = new ClassName(); | var_name | V
TODO:
var foo, bar, baz;- Special kinds for special types (RegExp, Math, Map, etc.)?
Tagging direct imports would be redundant so we only tag named imports.
--regex-javascript=/^[ \t]*import[ \t]\{1,\}\([{][ \t]*\)*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)\([A-Za-z0-9_]\{1,\}\)/\3/I,Import,Imports/b
--regex-javascript=/^[ \t]*import[ \t]\{1,\}\([{][ \t]*\)*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)*\([A-Za-z0-9_]\{1,\}\),[ \t]*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)\([A-Za-z0-9_]\{1,\}\)/\5/I,Import,Imports/b
--regex-javascript=/^[ \t]*import[ \t]\{1,\}\([{][ \t]*\)*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)*\([A-Za-z0-9_]\{1,\}\),[ \t]*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)*\([A-Za-z0-9_]\{1,\}\),[ \t]*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)\([A-Za-z0-9_]\{1,\}\)/\7/I,Import,Imports/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
import { * as imp1 } | imp1 | I
import { foo as imp2 } | imp2 | I
import { imp3, * as imp4 } | imp4 | I
import { imp5, bar as imp6 } | imp6 | I
import { imp7, imp8, * as imp9 } | imp9 | I
import { imp10, imp11, baz as imp12 } | imp12 | I
import { * as imp13, * as imp14, * as imp15 } | imp13, imp14, imp15 | I
import { foo as imp16, bar as imp17, baz as imp18 } | imp16, imp17, imp18 | I
import * as imp19 | imp19 | I
import foo as imp20 | imp20 | I
import imp21, * as imp22 | imp22 | I
import imp23, bar as imp24 | imp24 | I
import imp25, imp26, * as imp27 | imp27 | I
import imp28, imp29, baz as imp30 | imp30 | I
import * as imp31, * as imp32, * as imp33 | imp31, imp32, imp33 | I
import foo as imp34, bar as imp35, baz as imp36 | imp34, imp35, imp36 | I
Same story as imports, tagging direct exports would be redundant so we only tag named exports.
--regex-javascript=/^[ \t]*export[ \t]\{1,\}\({[ \t]*\)*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)\([A-Za-z0-9_]\{1,\}\)/\3/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}\({[ \t]*\)*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)*\([A-Za-z0-9_]\{1,\}\),[ \t]*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)\([A-Za-z0-9_]\{1,\}\)/\5/E,export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}\({[ \t]*\)*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)*\([A-Za-z0-9_]\{1,\}\),[ \t]*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)*\([A-Za-z0-9_]\{1,\}\),[ \t]*\([A-Za-z0-9_\*]*[ \t]as[ \t]\)\([A-Za-z0-9_]\{1,\}\)/\7/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}function[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\2/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\2/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\2/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*,[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\3/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*,[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\3/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*,[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\3/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}function[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)/\1/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\2/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\2/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\2/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*,[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\3/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*,[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\3/E,Export,Exports/b
--regex-javascript=/^[ \t]*export[ \t]\{1,\}default[ \t]\{1,\}const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*[^,]\{1,\},[ \t]*\([A-Za-z0-9_$]\{1,\}\)[ \t]*,[ \t]*\([A-Za-z0-9_$]\{1,\}\)/\3/E,Export,Exports/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
export { var1 as exp04, var2 as exp05 }; | exp04, exp05 | E
export let exp06, exp07; | exp06, exp07 | E
export var exp08, exp09, exp09b; | exp08, exp09 | E
export let exp10 = 1, exp11 = 2; | exp10, exp11 | E
export const exp12 = 1, exp13 = 2; | exp12, exp13 | E
export var exp14 = 1, exp15 = 2; | exp14, exp15 | E
export function exp16() {} | exp16 | E
export default { var1 as exp20, var2 as exp21}; | exp20; exp21 | E
export default let exp22, exp23; | exp22, exp23 | E
export default var exp24, exp25; | exp24, exp25 | E
export default let exp26 = 1, exp27 = 2; | exp26, exp27 | E
export default const exp28 = 1, exp29 = 2; | exp28, exp29 | E
export default var exp30 = 1, exp31 = 2; | exp30, exp31 | E
export default function exp32() {} | exp32 | E
"Visual primitives for the component age.", as they say on the site, are not exactly native types but they are certainly named and very likely to be reused so they deserve a spot, here.
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*styled/\1/S,StyledComponent,StyledComponents/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*styled/\1/S,StyledComponent,StyledComponents/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*styled/\1/S,StyledComponent,StyledComponents/b
--regex-javascript=/^[ \t]*var[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*createGlobalStyle/\1/S,StyledComponent,StyledComponents/b
--regex-javascript=/^[ \t]*let[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*createGlobalStyle/\1/S,StyledComponent,StyledComponents/b
--regex-javascript=/^[ \t]*const[ \t]\{1,\}\([A-Za-z0-9_$]\{1,\}\)[ \t]*=[ \t]*createGlobalStyle/\1/S,StyledComponent,StyledComponents/b
CODE | TAG | KIND
----------------------------------------------------|---------------------|-----
var Comp01 = styled... | Comp01 | S
let Comp02 = styled... | Comp02 | S
const Comp03 = styled... | Comp03 | S
var Comp04 = createGlobalStyle... | Comp04 | S
let Comp05 = createGlobalStyle... | Comp05 | S
const Comp05 = createGlobalStyle... | Comp06 | S
Because Exuberant Ctags takes no responsibility about the regular expression engine it uses under the hood, we must use the dumbest dialect, BRE, for portability. This has a number of consequences:
- no alternation,
- no lookbehind,
- no backreference,
- a verbose and frustrating syntax.
But we are hackers, right?
The bundled Makefile has a very simple and very cheap watch phony target that will run make tags every second. In turn, the tags target will run ctags --options=./ctagsrc -f tags index.js only if ctagsrc or index.js have changed since last run.
This allows us to start the watcher in a terminal:
$ make watch
open ctagsrc, index.js, and the tags file in Vim in another terminal:
$ vim -O tags ctagsrc index.js +'set autoread' +'autocmd! CursorHold,CursorHoldI * checktime'
and watch our tags file change as we edit existing patterns in ctagsrc or add expressions in index.js.