PsiBuilder.kt

import kotlinx.cinterop.*
import platform.posix.*

// IrFile
// ------------------------------------------------------
data class PsiFile internal constructor(val path: String, var name: String = path.substringAfterLast('/'))

val PsiFile.open get() = open(path, O_RDONLY)
val PsiFile.size get() = nativeHeap.alloc<stat>().apply { stat(path, ptr) }.st_size

// Extension -----------------
fun PsiFile.readUtf8() = run {
    val fd = open; val size = size
    mmap(NULL, size.convert(), PROT_READ, MAP_PRIVATE, fd, 0)?.readBytes(size.convert())
            ?.toKString() ?: throw Exception("Error reading lock file.")
} // ----------------------------------------------------

fun PsiFile.rawLoop(exe: (Byte) -> Unit) {
    val fd = open; val size = size
    val pointer = mmap(NULL, size.convert(), PROT_READ, MAP_PRIVATE, fd, 0)
    pointer?.reinterpret<ByteVar>()?.pointed?.ptr?.let { src ->
        var index = 0
        while (index < size) {
            exe(src[index])
            ++index
        }
    }
}


fun PsiFile.charLoop(exe: (Char) -> Unit) = rawLoop { exe(it.toChar()) }



//-----------------------------------------------------------

class PsiBuilder(val psiFile: PsiFile) {
    val fd = psiFile.open
    val size = psiFile.size

    private val pointer =
            mmap(NULL, size.convert(), PROT_READ, MAP_PRIVATE, fd, 0)
                    ?.reinterpret<ByteVar>()?.pointed?.ptr

    var marker = 0

    var nChar: Char? = null
    var pChar: Char? = ' '

    val isEnd get() = if (marker>=size) true else false


    fun nextChar(): Char? {
        val c = pointer?.get(marker)?.toChar()

        return nChar?.let { nChar.apply { nChar=null } } ?:

        when { // Run this if nextChar is null
            (pChar ==' ' && c ==' ') || c == '\r' || c == '\n' || c == '\t' -> null

            // Add space both side these characters
            pChar !=' ' && c == ',' -> { nChar = ','; ' ' }
            pChar ==',' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == ':' -> { nChar = ':'; ' ' }
            pChar ==':' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '=' -> { nChar = '='; ' ' }
            pChar =='=' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '!' -> { nChar = '!'; ' ' }
            pChar =='!' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '/' -> { nChar = '/'; ' ' }
            pChar =='/' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '{' -> { nChar = '{'; ' ' }
            pChar =='{' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '}' -> { nChar = '}'; ' ' }
            pChar =='}' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == ';' -> { nChar = ';'; ' ' }
            pChar ==';' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '(' -> { nChar = '('; ' ' }
            pChar =='(' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == ')' -> { nChar = ')'; ' ' }
            pChar ==')' && c != ' ' -> { nChar = c; ' ' }

            pChar !=' ' && c == '.' -> { nChar = '.'; ' ' }
            pChar =='.' && c != ' ' -> { nChar = c; ' ' }

            else -> c

        }.apply { marker++ /* Go to next marker if nextChar printed */ }.apply {
                pChar = c // update previous character
            }
    }


    fun nextIterator(): Char? = nextChar() ?: nextIterator()



    fun nextWord() : String? {
        var word = ""
        do {
            val c = nextIterator()
            if (c != ' ') word+=c
        } while (c != ' ' && !isEnd)
        return if (word=="" && !isEnd) nextWord() else word
    }
}