System

🔗Overview

The system module is auto-loaded in every compile, no import needed. It covers operators, conversion, introspection, JSON, OS access, and two internal CSS helpers.

🔗Operators

Bool/number operations: + - * / == != < <= > >=, not, and or && ||, is isnot, mutating += -= *= /=, and inc / dec.

var i = 0
$i = $i + 1
.a { z-index: $i; }

🔗String concatenation with &

The & operator concatenates strings with strings, ints, floats, bools, and JSON values.

var label = "p-" & 1   /* "p-1" */

🔗range

range(lo: int, hi: int) is iterable for for loops. Constant bounds inline to bytecode and are never invoked at runtime. The range is inclusive.

for i in range(1, 3):
  .p-${$i}
    z-index: $i
/* -> .p-1{z-index:1}.p-2{z-index:2}.p-3{z-index:3} */

🔗type

Returns the runtime type name of a value: "bool int float string json array object".

var t = type(42)   /* "int" */

🔗jsonType

Returns the JSON type name of a JSON value.

var t = jsonType(parseJSON("{\"a\": 1}"))

🔗toInt

Converts a float to int.

var i = toInt(1.9)   /* 1 */

🔗parseInt

Parses a string into an int.

var i = parseInt("42")

🔗toFloat

Converts an int to float.

var f = toFloat(2)   /* 2.0 */

🔗toString

Converts ints, floats, bools, JSON, objects, colors, lengths, and other typed values to strings.

var s = toString(42)   /* "42" */

🔗echo

Prints a value during compilation for debugging. Overloaded for strings, ints, floats, bools, JSON, objects, arrays, and typed values. echo inside a stylesheet emits nothing to CSS.

var x = 10
echo($x)

🔗assert

Asserts a condition at compile time.

assert($x > 0)

🔗len

Returns the length of a string, JSON value, or array.

var n = len("hello")   /* 5 */

🔗high

Returns the last index of a JSON value or array.

var h = high($arr)

🔗hasKey

Tests whether a JSON value or object has a key.

var ok = hasKey($data, "name")

🔗shuffle

Returns a randomized copy of an array.

var s = shuffle($items)

🔗parseJSON

Parses a string into a JSON value.

var data = parseJSON("{\"a\": 1}")

🔗loadJSON

Loads a JSON value from a file path.

var data = loadJSON("./tokens.json")

🔗remoteJSON

Fetches JSON from a URL, returning {status, headers, content}. Never throws; errors land in content.error.

var res = remoteJSON("https://example.com/tokens.json")

🔗readFile

Reads a file from disk into a string.

var text = readFile("./notes.txt")

🔗writeFile

Writes content to a file on disk.

writeFile("./out.txt", $text)

🔗sleep

Pauses compilation for the given milliseconds.

sleep(100)

🔗cssStr

Renders one value to its CSS display text. This is a parser-desugared internal helper; avoid direct use.

var s = cssStr($colorVar)

🔗cssJoin

Joins pre-stringified parts with literal separators. Used for dynamic multi-values such as margin: $a $b. This is a parser-desugared internal helper; avoid direct use.

.a { margin: $top $right; }

Getting Started

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Standard Library