VIM from dislike to dependence (22) -- automatic completion

In this article, we will discuss vim Self contained automatic completion function . Of course , There are many plug-ins for automatic completion , But understand vim The built-in function helps us better complete the function of plug-ins . Because I have seen some configuration files that configure the functions of plug-ins more difficult to use than the original , And only using basic functions may not be easy to use the original . So here is the usage of the original version , It can be regarded as helping you provide a benchmark in the future configuration .

make command

Before you know about automatic completion , Let's talk briefly first :make This command , It is similar to that introduced in the previous article :grep Command similar , It's also true shell A package of commands . By default, it encapsulates make command .

We are right. c/c++ Language execution :make That is, calling shell Medium make command . It will store the error information generated by compilation in quickfix In the list . We introduced how to operate in the previous section quickfix list . It also introduces how to :grep Command transformation . alike :make It also supports the transformation using the same method .

:make In command , Use makeprg To execute external commands , Use errorformat To format output to quickfix in . Their default values are as follows :

makeprg="make"

errorformag="errorformat=%*[^"]"%f"%*\D%l: %m,"%f"%*\D%l: %m,%-G%f:%l: (Each undeclared identifier is reported only once,%-G%f:%l:
for each function it appears in.),%-GIn file included from %f:%l:%c:,%-GIn file included from %f:%l:%c\,,%-GIn file incl
uded from %f:%l:%c,%-GIn file included from %f:%l,%-G%*[ ]from %f:%l:%c,%-G%*[ ]from %f:%l:,%-G%*[ ]from %f:%l\,,%-G%*[
]from %f:%l,%f:%l:%c:%m,%f(%l):%m,%f:%l:%m,"%f"\, line %l%*\D%c%*[^ ] %m,%D%*\a[%*\d]: Entering directory %*[`']%f',%X%*
\a[%*\d]: Leaving directory %*[`']%f',%D%*\a: Entering directory %*[`']%f',%X%*\a: Leaving directory %*[`']%f',%DMaking
%*\a in %f,%f|%l| %m"

Their values can be adjusted to suit different external commands . I'm not going to go into details here , I believe that the little friend who has read the last article should not be unfamiliar with this . Originally :make The order is vim A very useful command in , Should write a separate article . But it's in :grep It's too repetitive , So I decided to go over it when I introduced other contents . For more information, please refer to vim User's manual .

Automatic completion

Automatic completion can be triggered in insert mode , When we trigger the completion function ,vim A completion list will be established according to the contents of all buffers in the current editing session , Then detect according to the characters on the left side of the current cursor , See if you can find a part of the word in the table , If you can find it, you will filter the completion list with this unfinished word , So not all words that begin with it are filtered out , The rest form a pop-up menu for users to choose . The effect is as follows ：

In the above example , Because in order to re At the beginning, there was only require a , To show the completion effect, here we add a new one with re At the beginning return

We use <Ctrl +p> and <Ctrl + n> To switch between the previous and next items in the completion menu . In addition to this , We also have other shortcut keys for operating the completion menu .

• <Ctrl - n> : Use the next item from the completion list (next)
• <Ctrl - p> : Use the previous item from the completion list (prev)
• <Down> : And <Ctrl -n> identical
• <Up>: And <Ctrl - p> identical
• <Ctrl -y> : Confirm to use the currently selected match
• <Ctrl - e> : Restore the original entry
• <Ctrl -h> : Delete a character from the current match
• <Ctrl - l> : Add a character from the current match

Usually when inputting characters , If there is a match to match vim It will pop up automatically , Or you can use it manually <Ctrl - n> Pop up the match menu . After determining the match to be used, you can use <Ctrl-y> To confirm

Sometimes, although the menu of matching items pops up , But there are too many matches , And the words you need are too late in the list , It can be used at this time <Ctrl - e> To exit the menu , Manually enter a few characters to make the match more accurate . Or you can enter <Ctrl -p> Get to the first item , That is, our current input , Then enter the characters again to simplify the menu items , Then use <Ctrl - n> Pop up menu . Use this method to approach the desired result step by step

Custom completion item source

By default ,vim The complete items mainly come from the following places ：

1. Buffer list ：vim The most basic source of completion is the current buffer list . It can go through <Ctrl - x><Ctrl - n> To trigger the item .
2. Include files , All programming languages have the concept of including files , for example c/c++ Medium #include , python Medium import . Use <Ctrl-x><Ctrl-i> This option can be triggered , Give Way vim Extract the completion item from the included file .vim Self use c language-written , It can recognize c/c++ Keywords in language , We can specify include Item to make vim Know other different keywords . Commonly used programming languages vim Can recognize , So there is no need to modify include term .
3. Label file , We use ctags Or similar plug-ins will generate a label file , This file will scan the keywords in the code 、 function 、 The index of variables, etc. is put into a file for subsequent jump . At the same time, they will also generate a series of completion items into the completion list . have access to <Ctrl+x><Ctrl+]> To trigger

It is usually used directly <Ctrl + n> What triggers is the completion item in the current buffer list , Use <Ctrl+x> As a prefix , Other types of completion items can be triggered . One advantage of doing this is to try to simplify and complete the list , It reduces the process of manual traversal . But sometimes we don't know where the content I want comes from , Is there any way to do it , use <Ctrl + n> This button can call the completion items of all other sources ？

To do that , have access to complete This configuration item . This item contains a set of parameters represented by single characters separated by commas , When a parameter appears, it means that the position represented by the parameter needs to be scanned . Use set complete? You can see , The default is complete=.,w,b,u,t . We can use set complete-=i perhaps set complete+=k To delete or add a scanning location . Common location parameters are as follows ：

• . : Represents the buffer currently open
• w : Currently open window
• b : Current buffer list
• u : Currently in the buffer list , But the unopened buffer
• t : Current label file
• U : Currently open , Not a buffer in the buffer list
• k : The complement loaded from the dictionary file
• i : Read from the current file and the include file
• d : Read and use from the current file and the include file define Defined macro

Complete content can be used :h 'complete' Check it out. .

Use dictionary files

In the above discussion , We can know vim It is a dictionary file that can be customized and completed , Then generate matching from the dictionary . We can use <Ctrl-x><Ctrl-k> To load matches in the dictionary .

We can use set spell To start spell checking , Spell checking also produces new dictionary files . If you don't want to use this , You can also use set dictionary To specify a dictionary file containing one or more words .

In this case, we are nvim-config Create a new one in the directory spell.txt file , We write the following in it

require
return
request

And then use set dictionary=./spell.txt , Then delete init.lua Medium return , Input re And then use <Ctrl+x><Ctrl+k> At this time, we found that it had been loaded

Complete the whole line

In addition to completing words ,vim You can also complete the whole line , Use <Ctrl+x><Ctrl+l> It can trigger the operation of completing the whole line .
The source of the completion item in the completion line is the same as the completion word , It should be noted that the indentation at the beginning of the line will be automatically ignored when completing the line .

The operation of the completion line is the same as that introduced before yy perhaps :t The effect is the same , We should use them separately according to the actual situation .

Complete the file name

stay shell You can use <Tab> Key to automatically complete the file path ,vim Use in <Ctrl+x><Ctrl+f> To complete the file path and file name .

It should be noted that when we use relative paths to complete file names , Working directory is used , That is, from which directory you entered vim. We can do it in vim Use in :cd To switch working directories . For example, I am in nvim-config The root directory of this project is executed nvim init.lua, In this document, we hope to complete it quickly basic/settings.lua the , We found that it reported an error when completing

We can use it at this time :cd lua To switch the working directory to nvim-config/lua . At this time, it is OK to execute the completion order .

Generate complements according to specific programming languages

The above complement is a little useful when editing ordinary text , But as a programmer, if you can only use the above methods to complete the code, you will be crazy . Fortunately vim Provides something like other IDE That kind of completion method based on programming language . The shortcut key for using this completion method is <Ctrl+x><Ctrl+o> To enable this method , Need to start file type recognition .

nvim This feature has been enabled in , Therefore, there is no need to deliberately set , But here I still give its configuration .

vim.o.filetype="plugin"

perhaps vim The following code can be used in

set filetype=plugin
set nocompatiable #  Set up with vi  Are not compatible 

For example, we can try in css Use completion in the document

vim It does support the automatic completion of many languages , However, in order to get a complete experience, it is recommended to use various special completion plug-ins to get a better experience

Final summary

In this article , It introduces vim The main sources of the Chinese complement are ： Current buffer and buffer list 、 Include files 、 Tags generated by external programs, etc . At the same time, it also introduces how to use shortcut keys to complete different items , Now these shortcuts are summarized as follows ：

• <Ctrl + n> : Complete common keywords , Mainly from the buffer list and the current buffer
• <Ctrl+x><Ctrl+n> : And <Ctrl+n> The same effect
• <Ctrl+x><Ctrl+i> : Get the completion item from the include file
• <Ctrl+x><Ctrl+]> : Get the completion item from the external tag
• <Ctrl+x><Ctrl+k> : Get the completion item from the dictionary file
• <Ctrl+x><Ctrl+l> : Complete the whole line
• <Ctrl+x><Ctrl+f> : Complete the file name
• <Ctrl+x><Ctrl+o> : Complete according to the programming language