# RFC: variable declaration syntax using \`:=\`

**URL:** <https://forum.crystal-lang.org/t/rfc-variable-declaration-syntax-using/7623>\
**Category:** Crystal Contrib\
**Tags:** rfc\
**Created:** [January 20, 2025, 8:30am UTC](https://forum.crystal-lang.org/t/rfc-variable-declaration-syntax-using/7623 "2025-01-20T08:30:55Z")\
**Posts on this page:** 1\
**Showing post:** 35

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**Author:** ![zw963](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/zw963/32/1623_2.png) [@zw963](https://forum.crystal-lang.org/u/zw963)\
**Post date:** [January 23, 2025, 5:00pm UTC](https://forum.crystal-lang.org/t/rfc-variable-declaration-syntax-using/7623/35 "2025-01-23T17:00:19Z")

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Want to mention [cr-source-typer](https://github.com/Vici37/cr-source-typer) shards here, discuss:

> [@Exploring the Compiler](https://forum.crystal-lang.org/t/exploring-the-compiler/7343/9):
>
> Here’s version 0.1.0 of the creatively named cr-source-typer project: It works on my machine, but buyer beware and all that :) If you try it and find issues, please let me know so I can improve it! And another mini brain dump along the lines of the one that started this thread: Running the semantic process has a cleanup property; setting this to true will cause it to expand the returned ASTNode to contain all required files and expanded macros. Setting it to false doesn’t. After semantic h…

And the efforts for try to add into Crystal, [PR](https://github.com/crystal-lang/crystal/pull/15211)

It can add all types for method args and return value automatically, I really like it when write Crystal shard

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