README.org

#+TITLE: tengo-mode #+LANGUAGE: en #+OPTIONS: toc:nil num:nil

[[https://melpa.org/#/tengo-mode][file:https://melpa.org/packages/tengo-mode-badge.svg]]

A major mode for editing [[https://github.com/d5/tengo][Tengo]] script files in GNU Emacs.

Tengo is a small, dynamic, fast, secure scripting language for Go. This package provides syntax highlighting, indentation, and navigation support for Tengo source files (=.tengo=).

• Features

• Syntax Highlighting: Comprehensive highlighting for keywords, built-ins, constants, operators, strings, and comments.
• Context-Aware Indentation:
  • Smart indentation for braces {}, parentheses (), and brackets [].
  • Robust Logic: Correctly ignores braces found inside strings or comments (e.g., x := "{" will not trigger indentation).
• Navigation:
  • Support for beginning-of-defun (C-M-a) and end-of-defun (C-M-e).
  • Works with named functions (func foo()) and variable-assigned anonymous functions (foo := func()).
• Imenu Support: Indexing for top-level functions and variable declarations for quick navigation.
• Electric Support: Integration with electric-indent-mode.

• Installation

** Manual Installation

1. Download tengo-mode.el to a directory in your load-path (e.g., =~/.emacs.d/lisp/=).
2. Add the following to your Emacs configuration (.emacs or init.el):

#+BEGIN_SRC emacs-lisp (add-to-list 'load-path "~/.emacs.d/lisp/") (require 'tengo-mode) #+END_SRC

** Using use-package

If you have the file saved locally:

#+BEGIN_SRC emacs-lisp (use-package tengo-mode :load-path "~/.emacs.d/lisp/" :mode "\.tengo\'") #+END_SRC

** From MELPA

#+begin_src emacs-lisp (use-package tengo-mode :ensure t :mode "\.tengo\'") #+end_src

• Configuration

** Indentation Width

The default indentation is 4 spaces. You can change this by setting tengo-indent-offset:

#+BEGIN_SRC emacs-lisp (setq tengo-indent-offset 2) ; Set indentation to 2 spaces #+END_SRC

** Electric Pairs

To automatically close brackets and braces, it is recommended to enable electric-pair-mode globally or specifically for Tengo:

#+BEGIN_SRC emacs-lisp (add-hook 'tengo-mode-hook 'electric-pair-mode) #+END_SRC

• Keybindings

tengo-mode inherits from prog-mode, so standard Emacs movement keys apply.

| Keybinding | Command | Description | |------------+--------------------+------------------------------------------------| | TAB | tengo-indent-line | Indent the current line contextually. | | C-M-a | beginning-of-defun | Move to the beginning of the current function. | | C-M-e | end-of-defun | Move to the end of the current function. | | M-g i | imenu | Jump to a function or variable definition. |

• Credits

Based on the [[https://github.com/geseq/tengo-vim][tengo-vim]] plugin and the official Tengo language documentation.