How do you quickly navigate inside a source file using emacs ?

You can go to the next/previous function with C-M-a and C-M-e. With evil mode it's ] m and [ m. You can use imenu. You can make keybindings to scroll forwards/backwards several lines at a time.

consult-line

And I'm using outline-minor-mode

(setq-local outline-regexp " *//\\(-+\\)")

(outline-minor-mode 1)

Now every comment starting with // followed by one or more - like

//- Function this

//-- Function that

//--- Some important code

is treated like a heading by outline. So, you can use all the outline functions for navigating and folding.

Also you can use consult-outline (if installed) to jump quickly to a heading.

To make it even more convenient I recommend the packages bicycle and logos.

https://github.com/abo-abo/avy#avy-goto-char-timer is excellent for jumping to any text you can see on screen.

isearch and occur are excellent for jumping to specified text anywhere in the buffer.

imenu and xref-find-* are excellent for jumping to specific definitions in the buffer.

Here are some ways to move around. The first two are in vanilla Emacs. (There are previous functions corresponding to the next functions mentioned.)

• C-M-e and C-M-a: Move to next "defun" (function definition).

• Imenu, if you know the name of the thing (e.g. a definition) you`re looking for. (Various libraries let you complete/filter and cycle among candidates.)

• next-visible-thing. Moves to end of next THING. First nonconsecutive use prompts for THING type. Or use next-visible-thing to define such a command for a specific kind of THING (so no prompt needed for the kind).

  Requires library thing-cmds.el, which requires hide-comnt.el.

  Predefined THINGS (library thingatpt+.el needed for some):

  sexp, button, char, char-same-line, color, comment, decimal-number, defun, email, filename, hex-number, line, list, list-contents, non-nil-symbol-name, number, overlay, page, paragraph, region-or-word, sentence, string, string-contents, symbol, symbol-name, unquoted-list, url, whitespace, whitespace-&-newlines, word

  "Visible" means invisible text is skipped. Option ignore-comments-flag controls whether to also ignore text in comments.

• Command fw-to-next-thing. Moves to the start of the next THING (unlike next-visible-thing, which moves to its end).

  Requires libraries find-where.el and thingatpt+.el needed for some).

  Library find-where.el lets you get something at a position where an arbitrary predicate is true (not just a position at the start of a text THING), or move to such a position.

  E.g., function fw-next-thing returns the next THING and its position, and command fw-to-next-thing goes there.

  E.g., this defines a command to move to the beginning of the next sexp:

    (defun to-next-sexp (n)
      "Go to next start of a sexp."
      (interactive "p")
      (fw-to-next-thing 'sexp nil n))
  

  Likewise, for fw-next-where and fw-to-next-where, which look for the next place and some data where some predicate is satisfied.

  See the Commentary in find-where.el.

• Commands in library isearch-prop.el to search within the text of certain things.

  E.g., isearchp-imenu-non-interactive-function searches only within (or only outside of) definitions of functions that are not commands. isearch-property-forward searches only within text that has (or doesn't have) a given text or overlay property. isearchp-zones-forward searches only within (or only outside) the text of a given set of zones (i.e., within a noncontiguous region).

• The old library hideif.el lets you hide text that's within ifdefs.

https://www.emacswiki.org/emacs/download/thing-cmds.el

https://www.emacswiki.org/emacs/download/hide-comnt.el

https://www.emacswiki.org/emacs/download/find-where.el

https://www.emacswiki.org/emacs/download/thingatpt%2b.el

https://www.emacswiki.org/emacs/download/isearch-prop.el

Using treesitter you can have text objects that are if statements or functions or whatever. From there it is just a key binding away

consult-line

And I'm using outline-minor-mode

(setq-local outline-regexp " *//\\(-+\\)")

(outline-minor-mode 1)

Now every comment starting with // followed by one or more - like

//- Function this

//-- Function that

//--- Some important code

is treated like a heading by outline. So, you can use all the outline functions for navigating and folding.

Also you can use consult-outline (if installed) to jump quickly to a heading.

To make it even more convenient I recommend the packages bicycle and logos.

inside one file, I have difficulties going quickly up function by function

helm-occur

Just start typing and it will show you occurrences in a file; you can use C-n/C-p (or whatever you bind it to), and it will move the point in the buffer and show you the occurrence so you can see the surrounding text. If you C-g the point is left where you were, and if you just press enter your point will be placed at the occurence.

inside one file, I have difficulties going quickly up function by function

helm-occur

Just start typing and it will show you occurrences in a file; you can use C-n/C-p (or whatever you bind it to), and it will move the point in the buffer and show you the occurrence so you can see the surrounding text. If you C-g the point is left where you were, and if you just press enter your point will be placed at the occurence.

avy is good for quickly jumping between what's visible. Occur is brilliant, it might also be worth mentioning consult and embark.

Using treesitter you can have text objects that are if statements or functions or whatever. From there it is just a key binding away

I think the "hide-show" package is invaluable in navigating large files. You can see all functions collapsed in a file. Or, within a function, you can see all blocks of code {} collapsed.

forward-sexp

C-s

Ivy with Swiper is the best way to navigate large files or groups of files IMO.