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Added a section about typecasting #20

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71f1dae
Added a section about casting
tapple Dec 20, 2025
528d973
Casting -> Typecasting
tapple Dec 21, 2025
9147d4c
noted that uuid and string are no longer interchangable
tapple Dec 21, 2025
4da71c8
Clarify parentheses necessity in math.modf example
tapple Jan 7, 2026
e8dbef3
Add or expressions to convert nil to the LSL typecast value
tapple Jan 8, 2026
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32 changes: 30 additions & 2 deletions src/content/docs/script/learn-slua/from-lsl.mdx
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Original file line number Diff line number Diff line change
Expand Up @@ -57,7 +57,7 @@ float damage = 25.5;
string name = "Alice";
vector pos = <10, 20, 30>;
rotation rot = <0, 0, 0, 1>;
key uuid = "...";
key k = "...";
list items = [1, 2, 3];
```
</Fragment>
Expand All @@ -69,7 +69,7 @@ local damage: number = 25.5
local name: string = "Alice"
local pos: vector = vector(10, 20, 30)
local rot: quaternion = quaternion(0, 0, 0, 1)
local uuid: string = "..." -- keys are strings
local k: uuid = uuid("...")
local items: {number} = {1, 2, 3} -- tables, not lists
```
</Fragment>
Expand All @@ -79,6 +79,34 @@ local items: {number} = {1, 2, 3} -- tables, not lists
**Type annotations recommended!** While optional, they catch errors before runtime and make code self-documenting.
</Aside>

#### Typecasting
In many cases, luau does typecasting automatically. Here's how to do it explicitly:
<CodeComparison>
<Fragment slot="lsl">
```lsl
(integer)"-4.4";
(float)"25.5";
(string)99.9;
(vector)"<10, 20, 30>";
(rotation)"<0, 0, 0, 1>";
(key)"700843d3-0d15-c427-81ab-e9c8a0dcdb1e";
(list)"hello"; // equivilant to ["hello"]
```
</Fragment>
<Fragment slot="slua">
```luau
(math.modf(tonumber("-4.4") or 0)) -- extra parentheses sometimes necessary
tonumber("25.5") or 0
tostring(99.9)
tovector("<10, 20, 30>") or ZERO_VECTOR
toquaternion("<0, 0, 0, 1>") or ZERO_ROTATION
uuid("700843d3-0d15-c427-81ab-e9c8a0dcdb1e") or NULL_KEY
{"hello"} -- table, not list
```
</Fragment>
</CodeComparison>
LSL and Lua typecasts return different results on invalid input: LSL returns "zero"; lua returns `nil`. The Lua examples include an `or` expressions that converts `nil` to what LSL typecast would have returned

### Operators

| Operation | LSL | SLua | Notes |
Expand Down