🖋️ Extending Syntax

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ShellPen supports extending the built-in pen syntax.

Create an extension

To create an extension:

• Create a BASH function (this will be responsible for your custom syntax)
• Register the function with ShellPen via shellpen extend

Create Extension Function

# - hello
# This will add a "hello from the extension" comment to the code
helloExtension() {
  case "$1" in
    hello)
      # Use $PEN to call ShellPen commands from within your extension
      $PEN comment "hello from the extension"
      ;;
    *)
      # If your function does _not_ handle the incoming syntax
      # then you should 'return 1' to let ShellPen know that
      # your extension is not handling this command.
      return 1
      ;;
  esac
}

Register Extension Function

shellpen extend helloExtension

Try out your new extension!

- hello

# hello from the extension

Indentation with blocks

Indentation is automatically added when using if, while, for, case, et al.

Each block has a respective command to close the block, e.g. fi, done, esac.

You can implement your own blocks with open and close commands and indentation is automatically applied to commands added in your block.

Create an extension with open / close block syntax

# - myBlockOpen
# - myBlockClose
openCloseExtension() {
  case "$1" in
    myBlockOpen)
      $PEN comment "The block was opened"

      # To open a block, specify the command which
      # is used to _close_ the block by pushing
      # it onto the ShellPen indentation stack:
      $PEN --push "myClose"
      ;;
    myBlockClose)
      # To properly close the block, --pop
      # is used to note this block has been closed:
      $PEN --pop

      $PEN comment "The block was closed"
      ;;
    *)
      return 1
      ;;
  esac
}

Use the new block syntax

- echo "Example Program"
- myBlockOpen
  - echo "Hello from inside the block"
  - myBlockOpen
    - echo "Inner block!"
  - myBlockClose
- myBlockClose
- echo "Done!"

echo "Example Program"
# The block was opened"
  echo "Hello from inside the block"
  # The block was opened"
    echo "Inner block!"
  # The block was closed
# The block was closed
echo "Done!"