N _I|Mjq؂File not found. File not found. "lzD ;pO)F h0x10000040   File not found. " lzD ;p)F h 4:16   File not found. File not found. ,lY>e8p\ţ mж_I|?*vim9.txt* For Vim version 8.2. Last change: 2021 Mar 03 VIM REFERENCE MANUAL by Bram Moolenaar THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE Vim9 script commands and expressions. *Vim9* *vim9* Most expression help is in |eval.txt|. This file is about the new syntax and features in Vim9 script. THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE 1. What is Vim9 script? |Vim9-script| 2. Differences |vim9-differences| 3. New style functions |fast-functions| 4. Types |vim9-types| 5. Namespace, Import and Export |vim9script| 6. Future work: classes |vim9-classes| 9. Rationale |vim9-rationale| ============================================================================== 1. What is Vim9 script? *Vim9-script* THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE Vim script has been growing over time, while preserving backwards compatibility. That means bad choices from the past often can't be changed and compatibility with Vi restricts possible solutions. Execution is quite slow, each line is parsed every time it is executed. The main goal of Vim9 script is to drastically improve performance. This is accomplished by compiling commands into instructions that can be efficiently executed. An increase in execution speed of 10 to 100 times can be expected. A secondary goal is to avoid Vim-specific constructs and get closer to commonly used programming languages, such as JavaScript, TypeScript and Java. The performance improvements can only be achieved by not being 100% backwards compatible. For example, making function arguments available in the "a:" dictionary adds quite a lot of overhead. In a Vim9 function this dictionary is not available. Other differences are more subtle, such as how errors are handled. The Vim9 script syntax and semantics are used in: - a function defined with the `:def` command - a script file where the first command is `vim9script` - an autocommand defined in the context of the above - a command prefixed with the `vim9cmd` command modifier When using `:function` in a Vim9 script file the legacy syntax is used, with the highest |scriptversion|. However, this can be confusing and is therefore discouraged. Vim9 script and legacy Vim script can be mixed. There is no requirement to rewrite old scripts, they keep working as before. You may want to use a few `:def` functions for code that needs to be fast. *:vim9* *:vim9cmd* :vim9[cmd] {cmd} Execute {cmd} using Vim9 script syntax and semantics. Useful when typing a command and in a legacy script or function. ============================================================================== 2. Differences from legacy Vim script *vim9-differences* THIS IS STILL UNDER DEVELOPMENT - ANYTHING CAN BREAK - ANYTHING CAN CHANGE Overview ~ Brief summary of the differences you will most often encounter when using Vim9 script and `:def` functions; details are below: - Comments start with #, not ": > echo "hello" # comment - Using a backslash for line continuation is hardly ever needed: > echo "hello " .. yourName .. ", how are you?" - White space is required in many places. - Assign values without `:let`, declare variables with `:var`: > var count = 0 count += 3 - Constants can be declared with `:final` and `:const`: > final matches = [] # add matches const names = ['Betty', 'Peter'] # cannot be changed - `:final` cannot be used as an abbreviation of `:finally`. - Variables and functions are script-local by default. - Functions are declared with argument types and return type: > def CallMe(count: number, message: st