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Types

One of Silicon's biggest goals is to develop a simple but powerful type system that map well to WASM and Javascript.

Numeric

Idiomatic Silicon uses sum types.

Typically used as number

type integer = i32 | i64;
type float = f32 | f64;
type number = integer | float;
type decimal = int; // maps to BigInt
  • i32
  • i64
  • f32
  • f64

Silicon has 8 primitive data types

  • ref
  • vec
  • atom
  • bool
  • int (LEB128)
  • float
  • decimal (128 bit)
  • string - rune

Ref

ref = func_ref | extern_ref

Vec

vec - v128 for WASM. For SIMD instructions.

Atom

Atoms only have one value, themselves. $true and $false are atoms.

Declare an ATOM by using the $ sigil. Since atom have one value, they're immutable!

Numeric Types

Integer

int

Integers are whole numbers are LEB128 variable byte integers that can be signed, unsigned or uninterpreted. I may allow arbitrary sized like Zig u7. They start as 32 bits.

Maps best to Javascript's bigint.

Float

float

Floating point numbers are signed 32 or 64 bit (based on WASM mode)IEEE 754 floating point values can be positive or negative, and can include a fractional component.

Decimal

decimal

Silicon has a decimal type for high precision financial calculations. Decimal is actually encoded with WASM's 128 bit vector type used for SIMD instructions.

Character

Char is poorly defined. Unicode codepoint is clearly defined but doesn't always match the human definition, I.E one emoji can be 3+ codepoints.

Silicon only has strings. If one really needs a "character" type, type guards can be used.

    // define a string with width 1
    @let char: str(width=1)

Strings do not have length. Instead there are width,bytes,and codepoints

String

str

Silicon uses UTF-32 encoded strings. UTF-16 and UTF-8 are available as well.

@let name = "Nathan" // UTF-32
@let name = #UTF16 "Nathan"

No Length?

Strings don't have length because that is poorly defined. Strings have 3 properties: width, bytes, and runes (codepoints).

width is how many visual symbols wide the string is. Still ambigous since some systems may or may not combine multiple codepoints into one symbol. bytes is the number of bytes required to represent the string. runes alias for codepoints, is the number of unicode codepoints used to represent the string.

Example string

"ü❤️Silicon"

width = 9
bytes = 13
runes = 10

ü it one character wide. 2 bytes. 2 codepoints.

️❤️ is one charater wide. 4 bytes. 2 codepoints.

Emojis can get crazy with modifiers. 👩🏿‍🚀 This is a combination of (Woman) + (dark skin tone) + ZWJ + rocket.

So 👩🏿‍🚀 is actually 4 codepoints, 16 bytes and 1 'character' (wide).

Booleans

bool

@type bool = $true | $false

Booleans can only be one of two different values: true or false. This type is required by expressions such as if, while, and assert.

Null & Undefined

Silicon doesn't have these types. Optionals are used instead.

References

Silicon needs references. Since Silicon mainly targets WASM, it too has function and external references.

References are opaque is a type that hide its underlying encoding. WASM has this for security purposes and referencing types from C or other languages via FFI.