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Does emacs/spacemacs support nested C++ mode embedded in Rust Macro?

Reference: rust-cpp

Can emacs/spacemacs support nested mode in major mode? I'm used to vim and new to emacs/spacemacs.

Solution

  • General information

    You have access to a wiki listing some solutions to run several major modes at once:

    In your case, you will need to run 2 major modes in order to recognize C++ and Rust in the same buffer:

    A practical example with mmm-mode

    I suppose your Rust environment is already configured in your Emacs. The following will add c++-mode while the Rust major mode is running. In your Emacs configuration file, add the following snippet:

    (require 'mmm-mode)
(setq mmm-global-mode 'maybe)

(mmm-add-classes
 '((rust-cpp ; Name of the mmm class
    :submode c++-mode ; Additional major mode, here it is C++
    :front "^cpp! {[\n\r]+" ; Start tag for c++-mode
    :back "^}$"))) ; Stop tag for c++-mode

(mmm-add-mode-ext-class 'rust-mode nil 'rust-cpp)

    In your Rust code, c++-mode will be activated when the following pattern is present:

    cpp! {
    // your C++ code...
}

    I'll let you fine-tune the regular expression since I do not know the rules of rust-cpp when mixing Rust and C++.