Mercurial > vim
view runtime/doc/usr_50.txt @ 32721:94f4a488412e v9.0.1683
Updated runtime files
Commit: https://github.com/vim/vim/commit/6efb1980336ff324e9c57a4e282530b952fca816
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Aug 10 05:44:25 2023 +0200
Updated runtime files
This is a collection of various PRs from github that all require a minor
patch number:
1) https://github.com/vim/vim/pull/12612
Do not conflate dictionary key with end of block
2) https://github.com/vim/vim/pull/12729:
When saving and restoring 'undolevels', the constructs `&undolevels` and
`:set undolevels` are problematic.
The construct `&undolevels` reads an unpredictable value; it will be the
local option value (if one has been set), or the global option value
(otherwise), making it unsuitable for saving a value for later
restoration.
Similarly, if a local option value has been set for 'undolevels',
temporarily modifying the option via `:set undolevels` changes the local
value as well as the global value, requiring extra work to restore both
values.
Saving and restoring the option value in one step via the construct
`:let &undolevels = &undolevels` appears to make no changes to the
'undolevels' option, but if a local option has been set to a different
value than the global option, it has the unintended effect of changing
the global 'undolevels' value to the local value.
Update the documentation to explain these issues and recommend explicit
use of global and local option values when saving and restoring. Update
some unit tests to use `g:undolevels`.
3) https://github.com/vim/vim/pull/12702:
Problem: Pip requirements files are not recognized.
Solution: Add a pattern to match pip requirements files.
4) https://github.com/vim/vim/pull/12688:
Add indent file and tests for ABB Rapid
5) https://github.com/vim/vim/pull/12668:
Use Lua 5.1 numeric escapes in tests and add to CI
Only Lua 5.2+ and LuaJIT understand hexadecimal escapes in strings. Lua
5.1 only supports decimal escapes:
> A character in a string can also be specified by its numerical value
> using the escape sequence \ddd, where ddd is a sequence of up to three
> decimal digits. (Note that if a numerical escape is to be followed by a
> digit, it must be expressed using exactly three digits.) Strings in Lua
> can contain any 8-bit value, including embedded zeros, which can be
> specified as '\0'.
To make sure this works with Lua 5.4 and Lua 5.1 change the Vim CI to
run with Lua 5.1 as well as Lua 5.4
6) https://github.com/vim/vim/pull/12631:
Add hurl filetype detection
7) https://github.com/vim/vim/pull/12573:
Problem: Files for haskell persistent library are not recognized
Solution: Add pattern persistentmodels for haskell persistent library
closes: #12612
closes: #12729
closes: #12702
closes: #12688
closes: #12668
closes: #12631
closes: #12573
Co-authored-by: lacygoill <lacygoill@lacygoill.me>
Co-authored-by: Michael Henry <drmikehenry@drmikehenry.com>
Co-authored-by: ObserverOfTime <chronobserver@disroot.org>
Co-authored-by: KnoP-01 <knosowski@graeffrobotics.de>
Co-authored-by: James McCoy <jamessan@jamessan.com>
Co-authored-by: Jacob Pfeifer <jacob@pfeifer.dev>
Co-authored-by: Borys Lykah <lykahb@fastmail.com>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Thu, 10 Aug 2023 06:30:06 +0200 |
parents | f8116058ca76 |
children | 4635e43f2c6f |
line wrap: on
line source
*usr_50.txt* For Vim version 9.0. Last change: 2022 Jun 20 VIM USER MANUAL - by Bram Moolenaar Advanced Vim script writing |50.1| Exceptions |50.2| Function with variable number of arguments |50.3| Restoring the view Next chapter: |usr_51.txt| Create a plugin Previous chapter: |usr_45.txt| Select your language (local) Table of contents: |usr_toc.txt| ============================================================================== *50.1* Exceptions Let's start with an example: > try read ~/templates/pascal.tmpl catch /E484:/ echo "Sorry, the Pascal template file cannot be found." endtry The `read` command will fail if the file does not exist. Instead of generating an error message, this code catches the error and gives the user a message with more information. For the commands in between `try` and `endtry` errors are turned into exceptions. An exception is a string. In the case of an error the string contains the error message. And every error message has a number. In this case, the error we catch contains "E484:". This number is guaranteed to stay the same (the text may change, e.g., it may be translated). Besides being able to give a nice error message, Vim will also continue executing commands after the `:endtry`. Otherwise, once an uncaught error is encountered, execution of the script/function/mapping will be aborted. When the `read` command causes another error, the pattern "E484:" will not match in it. Thus this exception will not be caught and result in the usual error message and execution is aborted. You might be tempted to do this: > try read ~/templates/pascal.tmpl catch echo "Sorry, the Pascal template file cannot be found." endtry This means all errors are caught. But then you will not see an error that would indicate a completely different problem, such as "E21: Cannot make changes, 'modifiable' is off". Think twice before you catch any error! Another useful mechanism is the `finally` command: > var tmp = tempname() try exe ":.,$write " .. tmp exe "!filter " .. tmp :.,$delete exe ":$read " .. tmp finally delete(tmp) endtry This filters the lines from the cursor until the end of the file through the "filter" command, which takes a file name argument. No matter if the filtering works, if something goes wrong in between `try` and `finally` or the user cancels the filtering by pressing CTRL-C, the `delete(tmp)` call is always executed. This makes sure you don't leave the temporary file behind. The `finally` does not catch the exception, the error will still abort further execution. More information about exception handling can be found in the reference manual: |exception-handling|. ============================================================================== *50.2* Function with variable number of arguments Vim enables you to define functions that have a variable number of arguments. The following command, for instance, defines a function that must have 1 argument (start) and can have up to 20 additional arguments: > def Show(start: string, ...items: list<string>) The variable "items" will be a list in the function containing the extra arguments. You can use it like any list, for example: > def Show(start: string, ...items: list<string>) echohl Title echo "start is " .. start echohl None for index in range(len(items)) echon $" Arg {index} is {items[index]}" endfor echo enddef You can call it like this: > Show('Title', 'one', 'two', 'three') < start is Title Arg 0 is one Arg 1 is two Arg 2 is three ~ This uses the `echohl` command to specify the highlighting used for the following `echo` command. `echohl None` stops it again. The `echon` command works like `echo`, but doesn't output a line break. If you call it with one argument the "items" list will be empty. `range(len(items))` returns a list with the indexes, what `for` loops over, we'll explain that further down. ============================================================================== *50.3* Restoring the view Sometimes you want to jump around, make a change and then go back to the same position and view. For example to change something in the file header. This can be done with two functions: > var view = winsaveview() # Move around, make changes winrestview(view) ============================================================================== Next chapter: |usr_51.txt| Create a plugin Copyright: see |manual-copyright| vim:tw=78:ts=8:noet:ft=help:norl: