51 lines
1.5 KiB
Kotlin
51 lines
1.5 KiB
Kotlin
// version 1.1.2
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class Brainf__k(val prog: String, memSize: Int) {
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private val mem = IntArray(memSize)
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private var ip = 0
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private var dp = 0
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private val memVal get() = mem.getOrElse(dp) { 0 }
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fun execute() {
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while (ip < prog.length) {
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when (prog[ip++]) {
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'>' -> dp++
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'<' -> dp--
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'+' -> mem[dp] = memVal + 1
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'-' -> mem[dp] = memVal - 1
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',' -> mem[dp] = System.`in`.read()
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'.' -> print(memVal.toChar())
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'[' -> handleLoopStart()
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']' -> handleLoopEnd()
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}
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}
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}
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private fun handleLoopStart() {
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if (memVal != 0) return
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var depth = 1
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while (ip < prog.length) {
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when (prog[ip++]) {
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'[' -> depth++
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']' -> if (--depth == 0) return
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}
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}
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throw IllegalStateException("Could not find matching end bracket")
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}
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private fun handleLoopEnd() {
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var depth = 0
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while (ip >= 0) {
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when (prog[--ip]) {
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']' -> depth++
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'[' -> if (--depth == 0) return
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}
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}
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throw IllegalStateException("Could not find matching start bracket")
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}
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}
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fun main(args: Array<String>) {
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val prog = "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>."
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Brainf__k(prog, 10).execute()
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}
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