Document CTags

Author: kddnewton

README.md

@@ -15,6 +15,7 @@ It is built with only standard library dependencies. It additionally ships with
 - [CLI](#cli)
   - [ast](#ast)
   - [check](#check)
+  - [ctags](#ctags)
   - [expr](#expr)
   - [format](#format)
   - [json](#json)
@@ -139,6 +140,33 @@ To change the print width that you are checking against, specify the `--print-wi
 stree check --print-width=100 path/to/file.rb
 ```
 
+### ctags
+
+This command will output to stdout a set of tags suitable for usage with [ctags](https://github.com/universal-ctags/ctags).
+
+```sh
+stree ctags path/to/file.rb
+```
+
+For a file containing the following Ruby code:
+
+```ruby
+class Foo
+end
+
+class Bar < Foo
+end
+```
+
+you will receive:
+
+```
+!_TAG_FILE_FORMAT	2	/extended format; --format=1 will not append ;" to lines/
+!_TAG_FILE_SORTED	1	/0=unsorted, 1=sorted, 2=foldcase/
+Bar	test.rb	/^class Bar < Foo$/;"	c	inherits:Foo
+Foo	test.rb	/^class Foo$/;"	c
+```
+
 ### expr
 
 This command will output a Ruby case-match expression that would match correctly against the first expression of the input.

lib/syntax_tree/cli.rb

@@ -413,6 +413,9 @@ def run(item)
       #{Color.bold("stree check [--plugins=...] [--print-width=NUMBER] [-e SCRIPT] FILE")}
         Check that the given files are formatted as syntax tree would format them
 
+      #{Color.bold("stree ctags [-e SCRIPT] FILE")}
+        Print out a ctags-compatible index of the given files
+
       #{Color.bold("stree debug [--plugins=...] [--print-width=NUMBER] [-e SCRIPT] FILE")}
         Check that the given files can be formatted idempotently