Add YAML support

Add support for YAML format configuration files. In addition, this
commit adds instructions about YAML config files to the README, and it
also changes the README to encourage use of YAML instead of JSON.

1 files changed, 70 insertions, 25 deletions

diff --git a/README.md b/README.md
index b8896dc..07400a1 100644
--- a/README.md
+++ b/README.md
@@ -63,8 +63,8 @@ updated once it's placed in the proper location (the Dotbot repository can be
 updated independently).
 
 An bootstrap install shell script for git is given in
-[tools/git-submodule/install][git-install]. The script assumes that the
-configuration is located in `install.conf.json` and Dotbot is located in
+[tools/git-submodule/install][git-install]. By default, the script assumes that
+the configuration is located in `install.conf.yaml` and Dotbot is located in
 `dotbot`. The script automatically makes sure that the correct version of
 Dotbot is checked out in the submodule.
 
@@ -74,19 +74,20 @@ different VCS) is fairly straightforward.
 Configuration
 -------------
 
-Dotbot uses json-formatted configuration files to let you specify how to set up
-your dotfiles. Currently, Dotbot knows how to `link` files and folders, execute
-`shell` commands, and `clean` directories of broken symbolic links.
+Dotbot uses YAML-formatted (or JSON-formatted) configuration files to let you
+specify how to set up your dotfiles. Currently, Dotbot knows how to `link`
+files and folders, execute `shell` commands, and `clean` directories of broken
+symbolic links.
 
 **Ideally, bootstrap configurations should be idempotent. That is, the
 installer should be able to be run multiple times without causing any
 problems.** This makes a lot of things easier to do (in particular, syncing
 updates between machines becomes really easy).
 
-Dotbot configuration files are json arrays of tasks, where each task is a
-dictionary that contains a command name mapping to data for that command. Tasks
-are run in the order in which they are specified. Commands within a task do not
-have a defined ordering.
+Dotbot configuration files are YAML (or JSON) arrays of tasks, where each task
+is a dictionary that contains a command name mapping to data for that command.
+Tasks are run in the order in which they are specified. Commands within a task
+do not have a defined ordering.
 
 ### Link
 
@@ -108,23 +109,37 @@ the source path, specify "create" as true if the parent directory should be
 created if necessary, and specify "force" as true if the file or directory
 should be forcibly linked.
 
-##### Example
+##### Example (YAML)
+
+```yaml
+- link:
+    ~/.config/terminator:
+      create: true
+      path: config/terminator/
+    ~/.vim: vim/
+    ~/.vimrc: vimrc
+    ~/.zshrc:
+      force: true
+      path: zshrc
+```
+
+##### Example (JSON)
 
 ```json
-{
+[{
     "link": {
         "~/.config/terminator": {
-            "path": "config/terminator/",
-            "create": true
+            "create": true,
+            "path": "config/terminator/"
         },
-        "~/.vimrc": "vimrc",
         "~/.vim": "vim/",
+        "~/.vimrc": "vimrc",
         "~/.zshrc": {
-            "path": "zshrc",
-            "force": true
+            "force": true,
+            "path": "zshrc"
         }
     }
-}
+}]
 ```
 
 ### Shell
@@ -138,14 +153,21 @@ Shell commands are specified as an array of commands, where each command is a
 two element array containing the actual shell command as the first element and
 a human-readable description as the second element.
 
-##### Example
+##### Example (YAML)
+
+```yaml
+- shell:
+  - [mkdir -p ~/downloads, Creating downloads directory]
+```
+
+##### Example (JSON)
 
 ```json
-{
+[{
     "shell": [
         ["mkdir -p ~/downloads", "Creating downloads directory"]
     ]
-}
+}]
 ```
 
 ### Clean
@@ -158,18 +180,41 @@ to the dotfiles directory are removed.
 
 Clean commands are specified as an array of directories to be cleaned.
 
-##### Example
+##### Example (YAML)
+
+```yaml
+- clean: ['~']
+```
+
+##### Example (JSON)
 
 ```json
-{
+[{
     "clean": ["~"]
-}
+}]
 ```
 
 ### Full Example
 
 The configuration file format is pretty simple. Here's an example of a complete
 configuration. The conventional name for the configuration file is
+`install.conf.yaml`.
+
+```yaml
+- clean: ['~']
+
+- link:
+    ~/.dotfiles: ''
+    ~/.tmux.conf: tmux.conf
+    ~/.vim: vim/
+    ~/.vimrc: vimrc
+
+- shell:
+  - [git update-submodules, Installing/updating submodules]
+```
+
+The configuration file can also be written in JSON. Here is the JSON equivalent
+of the YAML configuration given above. The conventional name for this file is
 `install.conf.json`.
 
 ```json
@@ -181,8 +226,8 @@ configuration. The conventional name for the configuration file is
         "link": {
             "~/.dotfiles": "",
             "~/.tmux.conf": "tmux.conf",
-            "~/.vimrc": "vimrc",
-            "~/.vim": "vim/"
+            "~/.vim": "vim/",
+            "~/.vimrc": "vimrc"
         }
     },
     {