e

Braindead editor. Feels like Vim, only simpler. Inspired by kilo, of course, and a large swath of the code is similar.

It can be scripted through Lua.

Features

• Scripting through intuitive Lua interface
• Incremental search (and replace)
• Multiple modi (similar to Vim)
• Mnemonic movement (feels like Vim, just different enough for you to be frustrated)
• Limitless Undo (until memory runs out)
• Extensible syntax highlighting
• No global state in the library part (just in main.c)
• Can be used as a library
• Ships with syntax highlighting for
  • C/C++ (stable)
  • Python (experimental)
  • JavaScript (experimental)
  • Go (experimental)
  • Haskell (experimental)
  • Carp (experimental)
  • Markdown (unfinished)

Installation

git clone https://github.com/hellerve/e
cd e
make install # install_lua for Lua support

If there are any problems—particularly with Lua—, please refer to the Troubleshooting page on the wiki.

Usage

There are two major modes, init and edit. edit mode works like a normal text editor would. init mode enables the user to navigate and do meta work, such as saving the file, searching, and replacing.

init mode mnemonics

Use wasd or the arrow keys for movement. Editing (backspace, etc.) works normally.

• n: insert a line below the cursor and start editing (next)
• p: insert a line above the cursor and start editing (previous)
• b: jump to the beginning of the line and start editing
• t: jump to the end of the line and start editing (terminus)
• h: hide a line (delete it) and add it to the system clipboard (clipboard only on Windows and OS X)
• c: copy a line to the system clipboard (only on Windows and OS X)
• v: view (i.e. paste) the contents of the system clipboard (only on Windows and OS X)
• /: incremental highlighted search
• r: search and replace first occurrence
• R: search and replace all occurrences
• Space: quick save (might be prompted for a file name)

In meta mode (reachable by pressing the colon character :), there are the following commands:

• s: save and quit (might be prompted for a file name)
• q: exit (will abort if the file has unsaved content)
• !: force exit
• Number n: jump to line n

Writing syntax files

By default, e creates a directory called .estx in the user's home directory (the location is overridable by providing STXDIR to make install). There, e will search for syntax files on startup. Their grammar is very minimal, see the C file below:

displayname: c
extensions: .*\.cpp$
            .*\.hpp$
            .*\.c$
            .*\.h$
comment|no_sep: //.*$
keyword: (restrict|switch|if|while|for|break|continue|return|else|try|catch|else|struct|union|class|typedef|static|enum|case|asm|default|delete|do|explicit|export|extern|inline|namespace|new|public|private|protected|sizeof|template|this|typedef|typeid|typename|using|virtual|friend|goto)
type: (auto|bool|char|const|double|float|inline|int|mutable|register|short|unsigned|volatile|void|int8_t|int16_t|int32_t|int64_t|uint8_t|uint16_t|uint32_t|uint64_t|size_t|ssize_t|time_t)
comment|no_sep: /\*.*\*/
comment|no_sep: /\*.*
                 .*\*/
pragma: \s*#(include|pragma|define|undef) .*$
predefined: (NULL|stdout|stderr)
pragma: \s*#(ifdef|ifndef|if) .*$
pragma: \s*#(endif)
string|no_sep: "([^\\\"]|\\.)*"
string|no_sep: '([^\\\']|\\.)'
number: [+-]?([0-9]+([.][0-9]*)?|[.][0-9]+)[fl]?

displayname is the string displayed at the bottom of e. extensions is a list of regexes to match the filenames. Highlighting keys are comment, keyword, type, pragma, string, number, and predefined. By appending |no_sep, the user signals to e that no separator is needed, i.e. highlighting works even if the matched string is part of a longer word. The values are regexes.

If you provide a second regex (must by divided by a newline), e assumes that everything between the two matches should be colored (useful for e.g. multiline comments).

Scripting through Lua

The editor has scripting capabilities in Lua. Thus far I've only documented them in a blog post, but this post should give you a good overview of how to write Lua scripts for e. There is also an example .erc file in the repository that you can look at for inspiration.

That's it!

Tabs vs. Spaces

I personally always use spaces for indentation, thus e does the same. It will always convert all of the tabs in your file to spaces automatically for you, and I understand if that bit of behavior is undesired by some. It is very much by design, though, and probably won’t change.

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Have fun!