Built-in Functions

Zink ships with 28 built-in functions. No imports needed.

I/O

Function	Description	Example
`say`	Print to output	`say "hello"`

say is a keyword, not a function — it doesn't use parentheses.

Type Conversion

Function	Description	Example
`str(v)`	Convert to string	`str(42)` → `"42"`
`num(s)`	Convert to number	`num("42")` → `42`
`type(v)`	Get type name as string	`type(42)` → `"number"`

Math

Function	Description	Example
`floor(n)`	Round down	`floor(3.7)` → `3`
`ceil(n)`	Round up	`ceil(3.2)` → `4`
`round(n)`	Round to nearest	`round(3.5)` → `4`
`abs(n)`	Absolute value	`abs(-5)` → `5`
`sqrt(n)`	Square root	`sqrt(16)` → `4`
`pow(base, exp)`	Exponentiation	`pow(2, 8)` → `256`
`max(a, b)`	Larger of two	`max(3, 7)` → `7`
`min(a, b)`	Smaller of two	`min(3, 7)` → `3`
`random()`	Random float 0..1	`random()` → `0.4217`

Array Functions

Function	Description	Example
`len(arr)`	Number of elements	`len([1,2,3])` → `3`
`push(arr, value)`	Append to end (mutates)	`push(arr, 4)`
`pop(arr)`	Remove and return last	`pop(arr)` → last element
`reverse(arr)`	Reverse in place (mutates)	`reverse([1,2,3])` → `[3,2,1]`
`sort(arr)`	Sort in place (mutates)	`sort([3,1,2])` → `[1,2,3]`
`slice(arr, start, end)`	Sub-array (non-mutating)	`slice([1,2,3,4], 1, 3)` → `[2,3]`
`contains(arr, value)`	Check membership	`contains([1,2,3], 2)` → `true`
`join(arr, separator)`	Join into string	`join(["a","b"], ",")` → `"a,b"`
`range(start, end, step?)`	Generate number array	`range(0, 5, 1)` → `[0,1,2,3,4]`

String Functions

Function	Description	Example
`len(s)`	String length	`len("hi")` → `2`
`upper(s)`	To uppercase	`upper("hi")` → `"HI"`
`lower(s)`	To lowercase	`lower("HI")` → `"hi"`
`trim(s)`	Strip whitespace	`trim(" hi ")` → `"hi"`
`split(s, sep)`	Split into array	`split("a,b", ",")` → `["a","b"]`
`contains(s, sub)`	Check substring	`contains("abc", "bc")` → `true`
`slice(s, start, end)`	Extract substring	`slice("hello", 0, 2)` → `"he"`

Higher-Order Functions

Function	Description	Example
`map(arr, fn)`	Transform each element	`map([1,2,3], double)` → `[2,4,6]`
`filter(arr, fn)`	Keep matching elements	`filter([1,2,3,4], is_even)` → `[2,4]`
`reduce(arr, fn, initial)`	Fold into single value	`reduce([1,2,3], add, 0)` → `6`