Types & Functions

Every ilo function declares its parameter types and return type inline:

ilo

funcname param1:type param2:type>returntype;body

Type sigils

Sigil	Type	Description
n	Number	Integers and floats
t	Text	Strings
b	Boolean	true / false
_	Any	Wildcard — accepts any type
L	List	Ordered collection [1 2 3]
M	Map	Key-value pairs {"key" "val"}
R	Result	Success or error value
O	Optional	Nil or a value: O n

_ means “don’t care” — same as in match patterns. Use it for mixed-type lists (L _), results where you ignore a type (R _ t), or generic parameters (x:_).

Examples

ilo

dbl x:n>n;*x 2                            -- number → number
greet first:t last:t>t;cat first " " last -- text params, text return
truthy x:_>b;!!x                          -- any type, boolean return
pi>n;3.14159                              -- zero-arg function

Multiple statements

In a file, use newlines and indentation:

ilo

calc a:n b:n > n  -- two numbers in, number out
  s = + a b       -- sum
  p = * a b       -- product
  + s p           -- return sum + product

Inline, use ; instead:

Shell

ilo 'calc a:n b:n>n;s=+a b;p=*a b;+s p' 3 4

Each statement binds a variable or returns a value. The last expression is the return value.