Context-aware key help

[blukat29]

Vim Grammar http://takac.github.io/2013/01/30/vim-grammar/ http://takac.github.io/assets/grammar-slide.html http://stackoverflow.com/questions/1218390/what-is-your-most-productive-shortcut-with-vim/ http://yanpritzker.com/2011/12/16/learn-to-speak-vim-verbs-nouns-and-modifiers/

[blukat29]

1. Possible states: wait, partial, repeat, motion, operator, operatorMotion, action, search, ex
2. Using mode and state, given a keystroke, find out which type of command it is.
3. Find if such command is valid. If so, state transition happens.
4. Based on state machine events, update help display.

[blukat29]

For step 2, refer to... vim.js Key handling routine - the outermost callback invoked by CodeMirror. Below is pseudocode, with some logics omitted.

function handleKey(cm, key) {
    var vim = maybeInitVimState(cm); // initialize only at the first run.
    // Exit visual state on Esc.
    if (key == '<Esc>') {
        clearInputState(cm);
        if (vim.isVisualMode)
            vim.exitVisualMode();
    }
    // '0' is special case since it is both motion and repeat digit.
    if (key != '0' || (key == '0' &&  vim.inputState.getRepeat() == 0)) {
        command = commandDispatcher.matchCommand(key, defaultKeymap, vim);
    }
    // Not a command. (can be numbers)
    if (!command) {
        if (isNumber(key))
            vim.inputState.pushRepeatDigit(key);
        else
            (unknown command)
        return;
    }
    // Process key to key mapping.
    if (command.type == 'keyToKey') {
        this.handleKey(cm, command.toKeys[]);
    }
    // Process ordinary commands
    commandDispatcher.processCommand(cm, vim, command);
}
// Separate function for ex commands.
function handleEx(cm, input) {
    exCommandDispatcher.processCommand(cm, input);
}

[blukat29]

Close and continue on new issue.