clean up

src/main/kotlin/blitz/Batched.kt

@@ -0,0 +1,128 @@
+package blitz
+
+import kotlin.math.max
+import kotlin.math.min
+
+interface BatchIterator<T>: Iterator<T> {
+    fun next(limit: Int): List<T>
+    fun next(dest: Array<T>): Int
+    fun next(dest: MutableList<T>, limit: Int)
+}
+
+interface ByteBatchIterator: BatchIterator<Byte> {
+    fun nextBytes(limit: Int): ByteArray
+
+    fun nextBytes(dest: ByteArray): Int
+}
+
+interface BatchSequence<T>: Sequence<T> {
+    override fun iterator(): BatchIterator<T>
+}
+
+interface ByteBatchSequence: BatchSequence<Byte> {
+    override fun iterator(): ByteBatchIterator
+}
+
+/**
+ * Batches all get operations on the sequence.
+ */
+fun <T> BatchSequence<T>.batched(count: Int): BatchSequence<T> =
+    object : BatchSequence<T> {
+        inner class Iter: BatchIterator<T> {
+            val parent = this@batched.iterator()
+
+            var batch = mutableListOf<T>()
+
+            override fun next(limit: Int): List<T> {
+                if (!hasNext())
+                    throw Exception("no next")
+
+                val c = min(limit, batch.size)
+                val ret = batch.take(c)
+                batch.removeFirst(c)
+                return ret
+            }
+
+            override fun next(dest: MutableList<T>, limit: Int) {
+                if (!hasNext())
+                    throw Exception("no next")
+
+                val c = min(limit, batch.size)
+                dest.addAll(batch.subList(0, max(0, c-1)))
+                batch.removeFirst(c)
+                return
+            }
+
+            override fun next(dest: Array<T>): Int {
+                if (!hasNext())
+                    throw Exception("no next")
+
+                val c = min(dest.size, batch.size)
+                batch.subList(0, max(0, c-1)).forEachIndexed { i, t ->
+                    dest[i] = t
+                }
+                batch.removeFirst(c)
+                return c
+            }
+
+            override fun next(): T {
+                if (!hasNext())
+                    throw Exception("no next")
+                val v = batch.first()
+                batch.removeFirst()
+                return v
+            }
+
+            override fun hasNext(): Boolean {
+                while (batch.isEmpty()) {
+                    if (!parent.hasNext())
+                        return false
+                    parent.next(batch, count)
+                }
+                return true
+            }
+        }
+
+        override fun iterator(): BatchIterator<T> =
+            Iter()
+    }
+
+fun <T> Sequence<T>.asBatch(): BatchSequence<T> =
+    object : BatchSequence<T> {
+        inner class Iter: BatchIterator<T> {
+            var iter = this@asBatch.iterator()
+
+            override fun next(limit: Int): List<T> =
+                mutableListOf<T>()
+                    .also { next(it, limit) }
+
+            override fun next(dest: MutableList<T>, limit: Int) {
+                for (i in 0..<limit) {
+                    if (!iter.hasNext())
+                        break
+                    dest.add(iter.next())
+                }
+            }
+
+            override fun next(dest: Array<T>): Int {
+                var i = 0
+                while (i < dest.size) {
+                    if (!iter.hasNext())
+                        break
+                    dest[i ++] = iter.next()
+                }
+                return i
+            }
+
+            override fun next(): T {
+                return iter.next()
+            }
+
+            override fun hasNext(): Boolean {
+                return iter.hasNext()
+            }
+        }
+
+        override fun iterator(): BatchIterator<T> =
+            Iter()
+    }

src/main/kotlin/blitz/BatchedUtils.kt

@@ -0,0 +1,10 @@
+package blitz
+
+fun ByteBatchSequence.stringify(batch: Int = 64): Sequence<String> {
+    val iter = iterator()
+    return generateSequence {
+        if (iter.hasNext())
+            iter.nextBytes(batch).decodeToString()
+        else null
+    }
+}

src/main/kotlin/blitz/Contents.kt

@@ -0,0 +1,52 @@
+package blitz
+
+class Contents<T> internal constructor(
+    private val iterable: Iterable<T>
+): Iterable<T> {
+    override fun iterator(): Iterator<T> =
+        iterable.iterator()
+
+    override fun equals(other: Any?): Boolean {
+        if (other !is Contents<*>)
+            return false
+
+        val it1 = this.iterable.iterator()
+        val it2 = other.iterable.iterator()
+
+        while (true) {
+            val hasNext1 = it1.hasNext()
+            val hasNext2 = it2.hasNext()
+
+            if ((hasNext1 && !hasNext2) || (hasNext2 && !hasNext1))
+                return false
+
+            if (!hasNext1)
+                return true
+
+            if (it1.next() != it2.next())
+                return false
+        }
+    }
+
+    override fun hashCode(): Int =
+        iterable.hashCode()
+
+    override fun toString(): String =
+        joinToString(
+            separator = ", ",
+            prefix = "[",
+            postfix = "]"
+        ) {
+            it.toString()
+        }
+}
+
+
+val <T> Iterable<T>.contents get() =
+    Contents(this)
+
+val <T> Sequence<T>.contents get() =
+    Contents(this.asIterable())
+
+val <T> Array<T>.contents get() =
+    Contents(this.asIterable())

src/main/kotlin/blitz/Defer.kt

@@ -0,0 +1,46 @@
+package blitz
+
+fun interface DeferScope {
+    fun defer(block: () -> Unit)
+}
+
+interface ExecutionScope: DeferScope {
+    fun onError(block: () -> Unit)
+
+    fun error()
+
+    companion object {
+        fun create(
+            defer: (block: () -> Unit) -> Unit,
+            onError: (block: () -> Unit) -> Unit,
+            error: () -> Unit,
+        ) = object : ExecutionScope {
+            override fun defer(block: () -> Unit) =
+                defer(block)
+
+            override fun onError(block: () -> Unit) =
+                onError(block)
+
+            override fun error() =
+                error()
+        }
+    }
+}
+
+fun <R> resourceScoped(block: ExecutionScope.() -> R): R {
+    val defer = mutableListOf<() -> Unit>()
+    val onError = mutableListOf<() -> Unit>()
+    val scope = ExecutionScope.create(defer::add, onError::add) {
+        throw Exception("Manual error triggered")
+    }
+    val ex: Exception
+    try {
+        return block(scope)
+    } catch (e: Exception) {
+        ex = e
+        onError.forEach { it.invoke() }
+    } finally {
+        defer.forEach { it.invoke() }
+    }
+    throw ex
+}

src/main/kotlin/blitz/DelegateProperties.kt

@@ -0,0 +1,21 @@
+package blitz
+
+fun <T, O: Any> caching(tiedGet: Provider<T>, calc: (T) -> O) = object : Lazy<O> {
+    private var lastTiedV = tiedGet()
+    private var lastV: O? = null
+
+    override val value: O get() {
+        val nTied = tiedGet()
+        if (lastTiedV != nTied) {
+            lastTiedV = nTied
+            lastV = calc(nTied)
+            return lastV!!
+        }
+        if (lastV == null)
+            lastV = calc(nTied)
+        return lastV!!
+    }
+
+    override fun isInitialized(): Boolean =
+        lastTiedV == tiedGet() && lastV != null
+}

src/main/kotlin/blitz/Either.kt

@@ -0,0 +1,54 @@
+package blitz
+
+class Either<A, B> private constructor(
+    private val a: Obj<A>?,
+    private val b: Obj<B>?
+) {
+    fun getAOrNull(): A? =
+        a?.v
+
+    fun getA(): A =
+        (a ?: throw Exception("Value of Either is not of type A!")).v
+
+    fun getAOr(prov: Provider<A>): A =
+        getAOrNull() ?: prov()
+
+    fun getBOrNull(): B? =
+        b?.v
+
+    fun getB(): B =
+        (b ?: throw Exception("Value of Either is not of type B!")).v
+
+    fun getBOr(prov: Provider<B>): B =
+        getBOrNull() ?: prov()
+
+    val isA: Boolean =
+        a != null
+
+    val isB: Boolean =
+        b != null
+
+    fun <R> then(af: (A) -> R, bf: (B) -> R): R =
+        if (isA) af(a!!.v) else bf(b!!.v)
+
+    fun <RA> mapA(transform: (A) -> RA): Either<RA, B> =
+        Either(a.map(transform), b)
+
+    fun <RB> mapB(transform: (B) -> RB): Either<A, RB> =
+        Either(a, b.map(transform))
+
+    override fun toString(): String =
+        if (isA) "Either<A>($a)"
+        else "Either<B>($b)"
+
+    companion object {
+        fun <A, B> ofA(a: A): Either<A, B> =
+            Either(Obj(a), null)
+
+        fun <A, B> ofB(b: B): Either<A, B> =
+            Either(null, Obj(b))
+    }
+}
+
+fun <A, B, R> Either<A, B>.commonize(): R where A: R, B: R =
+    getAOrNull() ?: getB()

src/main/kotlin/blitz/Fnp.kt

@@ -0,0 +1,28 @@
+package blitz
+
+fun main(args: Array<String>) {
+    // pureCat(args)
+    //     .impure()
+
+    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)
+}
+
+// `cat` command
+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) }

src/main/kotlin/blitz/ListOps.kt

@@ -0,0 +1,13 @@
+package blitz
+
+fun <T> MutableList<T>.removeFirst(count: Int) {
+    repeat(count) {
+        removeFirst()
+    }
+}
+
+fun <T> MutableList<T>.removeLast(count: Int) {
+    repeat(count) {
+        removeLast()
+    }
+}

src/main/kotlin/blitz/Obj.kt

@@ -0,0 +1,11 @@
+package blitz
+
+data class Obj<T>(val v: T)
+
+fun <I, O> Obj<I>?.mapNotNull(transform: (I) -> O): Obj<O>? =
+    this?.v?.let { Obj(transform(it)) }
+
+fun <I, O> Obj<I>.map(transform: (I) -> O): Obj<O> =
+    Obj(transform(v))
+
+data class MutObj<T>(var v: T)

src/main/kotlin/blitz/OperationChain.kt

@@ -0,0 +1,85 @@
+package blitz
+
+class OperationChain<I, O> private constructor(
+    private val impl: Impl = Impl()
+) {
+    private var until = 0
+
+    private class Impl {
+        val seqe = mutableListOf<(Sequence<Any?>) -> Sequence<Any?>>()
+
+        var finalized = false
+
+        fun add(op: Operator<*, *>) {
+            seqe += { seq: Sequence<Any?> ->
+                seq.map(op as Operator<Any?, Any?>)
+            }
+        }
+
+        fun addFlat(op: Operator<*, Sequence<*>>) {
+            seqe += { seq: Sequence<Any?> ->
+                seq.flatMap(op as Operator<Any?, Sequence<Any?>>)
+            }
+        }
+    }
+
+    fun <NO> map(op: Operator<O, NO>): OperationChain<I, NO> =
+        OperationChain<I, NO>(impl.also { it.add(op) })
+            .also { it.until = this.until + 1 }
+
+    fun <NO> flatMap(op: Operator<O, Sequence<NO>>): OperationChain<I, NO> =
+        OperationChain<I, NO>(impl.also { it.addFlat(op) })
+            .also { it.until = this.until + 1 }
+
+    fun <NO> map(op: OperationChain<O, NO>): OperationChain<I, NO> {
+        if (!op.impl.finalized)
+            throw Exception("Can not map un-finalized operation chain onto operation chain!")
+        return flatMap(op::process)
+    }
+
+    fun <NO> modifier(op: Operator<Sequence<O>, Sequence<NO>>): OperationChain<I, NO> =
+        OperationChain<I, NO>(impl.also { it.seqe.add(op as (Sequence<Any?>) -> Sequence<Any?>) })
+            .also { it.until = this.until + 1 }
+
+    fun finalize(): OperationChain<I, O> {
+        if (impl.finalized)
+            throw Exception("Can't finalize a finalized OperationChain!")
+        impl.finalized = true
+        return this
+    }
+
+    fun process(v: I): Sequence<O> =
+        selfInitializingSequence {
+            var seq = sequenceOf<Any?>(v)
+            impl.seqe
+                .asSequence()
+                .take(until)
+                .forEach { op ->
+                    seq = op(seq)
+                }
+            seq as Sequence<O>
+        }
+
+    fun processAll(v: Sequence<I>): Sequence<O> =
+        v.flatMap { process(it) }
+
+    companion object {
+        internal fun <I> create(): OperationChain<I, I> =
+            OperationChain()
+    }
+}
+
+fun <T, O> Sequence<T>.map(chain: OperationChain<T, O>): Sequence<O> =
+    chain.processAll(this)
+
+fun <I> chain(): OperationChain<I, I> =
+    OperationChain.create()
+
+fun <I, O> OperationChain<I, O>.chunked(size: Int): OperationChain<I, List<O>> =
+    modifier { it.chunked(size) }
+
+fun <I, O, R> OperationChain<I, O>.chunked(size: Int, transform: (List<O>) -> R): OperationChain<I, R> =
+    modifier { it.chunked(size, transform) }
+
+fun <I, O> OperationChain<I, O>.filter(predicate: (O) -> Boolean): OperationChain<I, O> =
+    modifier { it.filter(predicate) }

src/main/kotlin/blitz/SequenceBase.kt

@@ -0,0 +1,42 @@
+package blitz
+
+interface IndexableSequence<T>: Sequence<T> {
+    operator fun get(index: Int): T
+}
+
+fun <T> IndexableSequence<T>.modifier(mod: (Sequence<T>) -> Sequence<T>) =
+    object : IndexableSequence<T> {
+        val other = mod(this@modifier)
+
+        override fun iterator(): Iterator<T> =
+            other.iterator()
+
+        override fun get(index: Int): T =
+            this@modifier[index]
+    }
+
+fun <T> Sequence<T>.asIndexable(): IndexableSequence<T> =
+    object : IndexableSequence<T> {
+        val iter = this@asIndexable.iterator()
+        val values = mutableListOf<T>()
+
+        override fun get(index: Int): T {
+            if (index >= values.size) {
+                repeat(index + 1 - values.size) {
+                    values.add(iter.next())
+                }
+            }
+            return values[index]
+        }
+
+        override fun iterator(): Iterator<T> =
+            object : Iterator<T> {
+                var i = 0
+
+                override fun hasNext(): Boolean =
+                    i < values.size || iter.hasNext()
+
+                override fun next(): T =
+                    get(i ++)
+            }
+    }

src/main/kotlin/blitz/SequenceCreators.kt

@@ -0,0 +1,75 @@
+package blitz
+
+import kotlin.math.max
+
+fun <T> lazySequence(vararg init: Pair<Int, T>, default: Obj<T>?, f: (Int, (Int) -> T) -> T): IndexableSequence<T> =
+    object : IndexableSequence<T> {
+        val map = mutableMapOf(*init)
+
+        var current: Int? = null
+
+        fun comp(iIn: Int): T {
+            val i = max(0, iIn)
+            if (current == i)
+                return (default ?: throw Exception("recursion detected")).v
+            return map[i] ?: let {
+                current = i
+                val res = f(i, ::comp)
+                map[i] = res
+                current = null
+                res
+            }
+        }
+
+        override fun get(index: Int) = comp(index)
+
+        override fun iterator(): Iterator<T> =
+            object : Iterator<T> {
+                override fun hasNext() = true
+
+                private var i = 0
+
+                override fun next(): T =
+                    comp(i ++)
+            }
+    }
+
+fun <T> easySequence(vararg init: Pair<Int, T?>, f: (Int, (Int) -> T?) -> T?): Sequence<T?> =
+    lazySequence(*init, default = Obj(null)) { i, ff ->
+        f(i) { index ->
+            var indexC = index
+            var v: T? = null
+            while (indexC > 0 && v == null)
+                v = ff(indexC --)
+            v
+        }
+    }
+
+fun <I, T> Sequence<I>.easyMappingSequence(
+    vararg init: Pair<Int, T?>,
+    f: (Int, (Int) -> T?, (Int) -> I) -> T?
+): Sequence<T?> {
+    val indexable = this.asIndexable()
+    return easySequence(*init) { i, ff ->
+        f(i, ff, indexable::get)
+    }.limitBy(indexable)
+        .removeNull()
+}
+
+fun <T> selfInitializingSequence(block: Provider<Sequence<T>>): Sequence<T> =
+    object : Sequence<T> {
+        val seq by lazy(block)
+
+        inner class Iter : Iterator<T> {
+            val iter = seq.iterator()
+
+            override fun hasNext(): Boolean =
+                iter.hasNext()
+
+            override fun next(): T =
+                iter.next()
+        }
+
+        override fun iterator(): Iterator<T> =
+            Iter()
+    }

src/main/kotlin/blitz/SequenceOps.kt

@@ -0,0 +1,25 @@
+package blitz
+
+fun <T> Sequence<T>.removeNull(): Sequence<T> =
+    mapNotNull { it }
+
+fun <T> IndexableSequence<T>.removeNull(): IndexableSequence<T> =
+    modifier { it.removeNull() }
+
+fun <A, B> Sequence<A>.limitBy(other: Sequence<B>): Sequence<A> =
+    object : Sequence<A> {
+        override fun iterator(): Iterator<A> =
+            object : Iterator<A> {
+                val s = this@limitBy.iterator()
+                val o = other.iterator()
+
+                override fun hasNext(): Boolean =
+                    o.hasNext() && s.hasNext()
+
+                override fun next(): A =
+                    s.next().also { o.next() }
+            }
+    }
+
+fun <A, B> IndexableSequence<A>.limitBy(other: Sequence<B>): IndexableSequence<A> =
+    modifier { it.limitBy(other) }

src/main/kotlin/blitz/Types.kt

@@ -0,0 +1,5 @@
+package blitz
+
+typealias Provider<T> = () -> T
+
+typealias Operator<I, O> = (I) -> O

src/main/kotlin/blitz/func/Combine.kt

@@ -0,0 +1,13 @@
+package blitz.func
+
+fun Sequence<Monad<Unit>>.combine(): Monad<Unit> =
+    Monad { this@combine.forEach { it.impure() } }
+
+fun Iterable<Monad<Unit>>.combineIter(): Monad<Unit> =
+    Monad { this@combineIter.forEach { it.impure() } }
+
+fun Monad<Sequence<Monad<Unit>>>.combine(): Monad<Unit> =
+    Monad { this@combine.impure().forEach { it.impure() } }
+
+fun Monad<Iterable<Monad<Unit>>>.combineIter(): Monad<Unit> =
+    Monad { this@combineIter.impure().forEach { it.impure() } }

src/main/kotlin/blitz/func/Map.kt

@@ -0,0 +1,7 @@
+package blitz.func
+
+fun <T, R> Monad<Iterable<T>>.mapIter(transform: (T) -> R): Monad<Iterable<R>> =
+    bind { it.map { x -> transform(x) } }
+
+fun <T, R> Monad<Sequence<T>>.map(transform: (T) -> R): Monad<Sequence<R>> =
+    bind { it.map { x -> transform(x) } }

src/main/kotlin/blitz/func/Monad.kt

@@ -0,0 +1,14 @@
+package blitz.func
+
+class Monad<O> internal constructor(
+    val impure: () -> O
+)
+
+fun <O> unit(v: O): Monad<O> =
+    Monad { v }
+
+fun unit(): Monad<Unit> =
+    Monad { }
+
+fun <I, O> Monad<I>.bind(op: (I) -> O): Monad<O> =
+    Monad { op(this@bind.impure()) }

src/main/kotlin/blitz/func/Reduce.kt

@@ -0,0 +1,14 @@
+package blitz.func
+
+fun <S, T : S> Monad<Sequence<T>>.reduce(operation: (acc: S, T) -> S): Monad<S> =
+    bind { it.reduce(operation) }
+
+fun <S, T : S> Monad<Iterable<T>>.reduceIter(operation: (acc: S, T) -> S): Monad<S> =
+    bind { it.reduce(operation) }
+
+fun <T> Monad<Sequence<T>>.reduce(each: (T) -> Unit): Monad<Unit> =
+    Monad { this@reduce.impure().forEach { each(it) } }
+
+
+fun <T> Monad<Iterable<T>>.reduceIter(each: (T) -> Unit): Monad<Unit> =
+    Monad { this@reduceIter.impure().forEach { each(it) } }

src/main/kotlin/blitz/func/Rewrap.kt

@@ -0,0 +1,16 @@
+package blitz.func
+
+fun <T> Iterable<Monad<T>>.rewrap(): Monad<Sequence<T>> =
+    Monad {
+        val iter = this@rewrap.iterator()
+        generateSequence {
+            if (iter.hasNext())iter.next().impure()
+            else null
+        }
+    }
+
+fun <T> Sequence<Monad<T>>.rewrap(): Monad<Sequence<T>> =
+    Monad {
+        val iter = this@rewrap.iterator()
+        sequence { if (iter.hasNext()) yield(iter.next().impure()) }
+    }

src/main/kotlin/blitz/func/Utils.kt

@@ -0,0 +1,10 @@
+package blitz.func
+
+import blitz.ByteBatchSequence
+import blitz.stringify
+
+fun <T> Monad<Sequence<Sequence<T>>>.flatten(): Monad<Sequence<T>> =
+    bind { it.flatten() }
+
+fun Monad<ByteBatchSequence>.stringify(batch: Int = 64): Monad<Sequence<String>> =
+    bind { it.stringify(batch) }

src/main/kotlin/blitz/func/io/Console.kt

@@ -0,0 +1,9 @@
+package blitz.func.io
+
+import blitz.func.*
+
+fun Monad<String>.print() =
+    bind { print(it) }
+
+fun readIn() =
+    Monad { generateSequence { readln() } }

src/main/kotlin/blitz/func/io/File.kt

@@ -0,0 +1,13 @@
+package blitz.func.io
+
+import blitz.func.Monad
+import blitz.func.bind
+import blitz.io.readerSequence
+import kotlinx.io.files.Path
+import kotlinx.io.files.SystemFileSystem
+
+fun Monad<String>.asPath() =
+    bind { Path(it) }
+
+fun Monad<Path>.read() =
+    bind { p -> { SystemFileSystem.source(p) }.readerSequence() }

src/main/kotlin/blitz/io/Raw.kt

@@ -0,0 +1,51 @@
+package blitz.io
+
+import kotlinx.io.RawSource
+import kotlinx.io.buffered
+import blitz.ByteBatchIterator
+import blitz.ByteBatchSequence
+import blitz.Provider
+
+fun Provider<RawSource>.readerSequence(): ByteBatchSequence =
+    object : ByteBatchSequence {
+        inner class Iter: ByteBatchIterator {
+            val buffered = this@readerSequence().buffered()
+
+            override fun nextBytes(limit: Int): ByteArray {
+                val out = ByteArray(limit)
+                var i = 0
+                while (!(buffered.exhausted() || i == limit - 1))
+                    out[i ++] = buffered.readByte()
+                return out.sliceArray(0..i)
+            }
+
+            override fun nextBytes(dest: ByteArray): Int =
+                nextBytes(dest.size).also { it.copyInto(dest) }.size
+
+            override fun next(limit: Int): List<Byte> =
+                nextBytes(limit).toList()
+
+            override fun next(dest: MutableList<Byte>, limit: Int) {
+                for (x in nextBytes(limit)) {
+                    dest.add(x)
+                }
+            }
+
+            override fun next(dest: Array<Byte>): Int {
+                var i = 0
+                for (x in nextBytes(dest.size)) {
+                    dest[i ++] = x
+                }
+                return i
+            }
+
+            override fun next(): Byte =
+                buffered.readByte()
+
+            override fun hasNext(): Boolean =
+                !buffered.exhausted()
+        }
+
+        override fun iterator(): ByteBatchIterator =
+            Iter()
+    }