Those features are available in emacs, and work in both the GUI and the terminal.
For auto-complete, vanilla emacs has dynamic abbreviations; there are several packages for fancier auto-completion; company-mode, for example, works just fine in the terminal, as well of course as in the GUI (X11, macOS or Windows).
Likewise with tooltips, which in the terminal generally are generally displayed in a special region of the terminal instead.
Likewise with context menus, which can be shown just fine in a VT100 terminal.
Likewise with expanding & collapsing text ('folding'). Org-mode, to take just one example, is built on folding — and is easily one of modern emacs's killer features.
Seriously, give emacs a shot. Both Prelude & spacemacs are excellent configs for it.
> give emacs a shot. Both Prelude & spacemacs are excellent configs for it.
Are there any advantages over Visual Studio + Visual Assist, for C++ or C# languages?
Because I see many disadvantages.
About text editor features, your workarounds have flaws compared to good GUI. For tooltips, that special region of the terminal is physically separate from the cursor. For folding, a separate, visually distinct indicators of what’s folded/unfolded help navigating the code faster.
Another text editor feature hard to do in text mode is spell checking for strings and comments. Color is already used for syntax highlighting, so wavy red underlines come handy.
But visual studio is more than an editor, it includes a build system, debuggers and profilers, package manager, and many more related features. Everything comes already integrated and just works out of the box.
> Are there any advantages over Visual Studio + Visual Assist, for C++ or C# languages?
A fully-extensible, flexible environment which anyone (even a secretary!) can easily extend.
> About text editor features, your workarounds have flaws compared to good GUI.
They're not workarounds; they are the features. emacs has a GUI. I repeat: emacs has a GUI. Tooltips in a GUI display as you'd expect. Folding in a GUI displays as you'd expect.
> Another text editor feature hard to do in text mode is spell checking for strings and comments. Color is already used for syntax highlighting, so wavy red underlines come handy.
Terminals support underlines!
> But visual studio is more than an editor, it includes a build system, debuggers and profilers, package manager, and many more related features.
Have you ever used emacs? It's more than an editor; it connects to build systems like make, maven, gradle, ant, what-have-you. It has its own elisp debugger, connects to gdb, SLIME provides an integrated Common Lisp debugger &c. It has a profiler. It has a package manager. It has a best-of-breed git interface, Magit. It has a best-of-breed personal organiser, Org-mode. It has multiple email clients (rmail, vm, gnus & notmuch come to mind, but there are probably more). It has multiple web browsers (emacs-w3m, eww, w3 & a new experimental WebKit-based browser). It has multiple image viewers. It has multiple terminals & its own shell.
Emacs is far, far 'more than an editor.' It's probably the single editor which is the furthest from being just an editor. Don't trust me: give it a shot! It really is a wonderful experience.
And yes, it has a GUI. Images, scrollbars, menubar, toolbar: the works. Runs on X11, macOS & Windows. And it also runs perfectly well in a VT100 terminal. You can use the same emacs locally and remotely, over SSH. It's pretty awesome.
> which anyone (even a secretary!) can easily extend
Even if that’s true, we’re talking about development environments here, so secretaries are irrelevant. I’ve been programming C++ and C# for decades, for me, visual studio is quite flexible and extensible.
> Terminals support underlines
I specifically told about wavy red underlines for spell checking, and terminals don’t support that. Simple underlines are too intrusive i.e. they often mask '_', and don’t stand out visually from normal text.
> It's more than an editor; it connects to build systems like make, maven, gradle, ant, what-have-you.
I know it’s possible to integrate everything in Linux ecosystem. I just don’t want to waste my time connecting, integrating, and then supporting the setup that just works out of the box on Windows, with freeware visual studio.
Another text editor feature hard to do in text mode is spell checking for strings and comments. Color is already used for syntax highlighting, so wavy red underlines come handy.
Terminals do have rich text, I have to point that out. Not conhost, the default one on Windows (though I think the latest Windows update might have it).
So you can have underline, bold, italic, squiggles, I think even strikethrough. Also you can have tooltip "windows" but since they're harder to create and manage few applications use them. Those that do are generally based on ncurses, a library for TUI (think Norton Commander or Turbo Pascal)
Vim even has a spell checker built in.
What the terminal does not have is usually consistent support because terminal emulators are really shady, there's no actual standard (most just do what xterm does). For the TUI thing, there's also no real conventions plus I'm pretty sure both Vim and Emacs don't use ncurses and roll their own (see: lack of consistency).
You also need to cobble things together out of packages with varying degrees of quality and documentation, from long forgotten wikis and 90's pages belongings to ex post-docs.
For auto-complete, vanilla emacs has dynamic abbreviations; there are several packages for fancier auto-completion; company-mode, for example, works just fine in the terminal, as well of course as in the GUI (X11, macOS or Windows).
Likewise with tooltips, which in the terminal generally are generally displayed in a special region of the terminal instead.
Likewise with context menus, which can be shown just fine in a VT100 terminal.
Likewise with expanding & collapsing text ('folding'). Org-mode, to take just one example, is built on folding — and is easily one of modern emacs's killer features.
Seriously, give emacs a shot. Both Prelude & spacemacs are excellent configs for it.