Blitz

Big Kotlin library adding features that the Kotlin standard library just does not have (and might never get)

How to get

repositories {
    maven {
        name = "alex's repo"
        url = uri("http://207.180.202.42:8080/libs")
        isAllowInsecureProtocol = true
    }
}

dependencies {
    implementation("me.alex_s168:blitz:0.10")
}

Examples

Fibonacci sequence

val fib = lazySequence(0 to 1) { i, f ->
  f(i-1) + f(i-2)
}

println(fib[10])

Terminal colors

Terminal.print("Hello, ", Terminal.STYLES.BOLD)
Terminal.println("World!", Terminal.COLORS.RED.brighter.fg, Terminal.COLORS.WHITE.bg)

Unix uniq

val inp = sequenceOf("AAA", "BBB", "AAA", "AAA", "AAA", "BBB")
val out = inp.easyMappingSequence { i, s, m ->
    if (s(i-1) == m(i)) null
    else m(i)
}
println(out.contents)

Reading files

val file = Path.of("test.txt")  // Path
    .getFile()                  // File

val text = file.read()          // ByteBatchSequence
    .stringify()                // Sequence<String>   // (NOT lines!!)
    .flatten()                  // String

Bit fields

class Flags: BitField() {
    var direction by bit(0)
    var moving by bit(1)
    var frontLight by bit(2)
}

val byte = getByteFromSomewhere()
val flags = Flags().decode(byte)
flags.direction = !flags.direction
putByteSomewhere(flags.encode())

Unix cat with monads (pure)

fun pureCat(args: Array<String>): Monad<Unit> =
    args
    .ifEmpty { arrayOf("-") }
    .map {
        if (it == "-") readIn()
        else unit(it)
            .asPath()
            .read()
            .stringify()
    }
    .rewrap()
    .flatten()
    .reduce { s -> print(s) }

Numbers to bytes

val num: Short = 5
val bytes = num.toBytes(Endian.LITTLE)

Caching delegate property

class Label {
    var font = "Arial 11"
    val fontWith by caching(::font) {
        someFunctionToCalculate(it)
    }
}

Contents

val a = listOf(1, 2, 3, 4)
val b = arrayOf(1, 2, 3, 4)
println(a.contents == b.contents) // true
println(b.contents) // [1, 2, 3, 4]

Code error messages

val source = Errors.Source("main.kt", MutMultiLineString.from("""
    fn main() {
        return 1 + 0
    }
""".trimIndent(), ' '))

val errors = listOf(
    Errors.Error(
        "cannot return integer from function with return type void",
        Errors.Error.Level.ERROR,
        Errors.Location(source, 1, 11, 5)
    ),
    Errors.Error(
        "return is deprecated. use yeet instead",
        Errors.Error.Level.WARN,
        Errors.Location(source, 1, 4, 6)
    ),
    Errors.Error(
        "useless addition",
        Errors.Error.Level.INFO,
        Errors.Location(source, 1, 13, 3),
        isHint = true
    ),
    Errors.Error(
        "Visit https://www.example.com/doc/yeet for more information",
        Errors.Error.Level.INFO,
        Errors.Location(source, 1, 0, 0),
        isLongDesc = true
    )
)

val config = Errors.PrintConfig()

Errors.print(config, errors)

Output:

Split with nesting

val inp = "arr[int], long, long, arr[double], int"
val split = inp.splitWithNesting(',', nestUp = '[', nestDown = ']')
println(split)

Expression parsing

val input = "sin(max(2, 3) / (3 * pi))".iterator()
val tok = input.tokenize(
        ignore = listOf(' ', '\n'),
        operators = listOf(
            Operator('+', 2, true),
            Operator('-', 2, true),

            Operator('*', 3, true),
            Operator('/', 3, true),
            Operator('%', 3, true),

            Operator('~', 10, false),
        )
    )
val rpn = tok.shuntingYard().collect()
if (input.hasNext())
    error("Unexpected token(s): ${input.collectToString()}")
println(rpn)
// outputs:
// [
//      Token(type=NUMBER, value=2, op=null),
//      Token(type=NUMBER, value=3, op=null),
//      Token(type=IDENT, value=max, op=null),
//      Token(type=NUMBER, value=3, op=null),
//      Token(type=IDENT, value=pi, op=null),
//      Token(type=OPERATOR, value=null, op=Operator(symbol=*, precedence=3, leftAssociative=true)),
//      Token(type=OPERATOR, value=null, op=Operator(symbol=/, precedence=3, leftAssociative=true)),
//      Token(type=IDENT, value=sin, op=null)
// ]

SortedList

val list = SortedArrayList<Int> { it }
list.add(1)
list.add(9)
list.add(5)
println(list.contents)
// outputs: [1, 5, 9]

Either

No example yet

Tree

No example yet