From d509305be04f319230635010685a9ddc59c17987 Mon Sep 17 00:00:00 2001 From: dundargoc Date: Wed, 13 Dec 2023 11:09:54 +0100 Subject: [PATCH] Revert "Remove code-overview" This reverts commit c6ff8c8349d7c54eeabf537aa1d7b53819fbe4ee. --- Code-overview.md | 70 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 Code-overview.md diff --git a/Code-overview.md b/Code-overview.md new file mode 100644 index 0000000..6338ec0 --- /dev/null +++ b/Code-overview.md @@ -0,0 +1,70 @@ +Here are a few hints for finding your way around the source code. This +doesn't make it less complex than it is, but it gets you started. + +## Important variables + +The current mode is stored in `State`. The values it can have are `MODE_NORMAL`, +`MODE_INSERT`, `MODE_CMDLINE`, and a few others. + +The current window is `curwin`. The current buffer is `curbuf`. These point +to structures with the cursor position in the window, option values, the file +name, etc. + +All the global variables are declared in [globals.h](../blob/master/src/nvim/globals.h). + + +## The main loop + +The main loop is implemented in state_enter. The basic idea is that Vim waits +for the user to type a character and processes it until another character is +needed. Thus there are several places where Vim waits for a character to be +typed. The `vgetc()` function is used for this. It also handles mapping. + +Updating the screen is mostly postponed until a command or a sequence of +commands has finished. The work is done by `update_screen()`, which calls +`win_update()` for every window, which calls `win_line()` for every line. +See the start of [drawscreen.c](../blob/master/src/nvim/drawscreen.c) for more explanations. + + +## Command-line mode + +When typing a `:`, `normal_cmd()` will call `getcmdline()` to obtain a line with +an Ex command. `getcmdline()` calls a loop that will handle each typed +character. It returns when hitting `` or `` or some other character that +ends the command line mode. + + +## Ex commands + +Ex commands are handled by the function `do_cmdline()`. It does the generic +parsing of the `:` command line and calls `do_one_cmd()` for each separate +command. It also takes care of while loops. + +`do_one_cmd()` parses the range and generic arguments and puts them in the +exarg_t and passes it to the function that handles the command. + +The `:` commands are listed in [ex_cmds.lua](../blob/master/src/nvim/ex_cmds.lua). + + +## Normal mode commands + +The Normal mode commands are handled by the `normal_cmd()` function. It also +handles the optional count and an extra character for some commands. These +are passed in a `cmdarg_T` to the function that handles the command. + +There is a table `nv_cmds` in [normal.c](../blob/master/src/nvim/normal.c) which +lists the first character of every +command. The second entry of each item is the name of the function that +handles the command. + + +## Insert mode commands + +When doing an `i` or `a` command, `normal_cmd()` will call the `edit()` function. +It contains a loop that waits for the next character and handles it. It +returns when leaving Insert mode. + + +## Options + +There is a list with all option names in [options.lua](../blob/master/src/nvim/options.lua).