SylvainHocq

/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Circle Internet Financial
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is

SylvainHocq

fun getReadLinesObservable(ctx: Context, fileName: String): Observable<String> {
    return Observable
        .create { emitter:Emitter<String> ->
            val input: BufferedReader
            try {
                val open = ctx.assets.open(fileName)
                input = BufferedReader(InputStreamReader(open))
                var line = input.readLine()
                while (line != null) {
                    emitter.onNext(line)

SylvainHocq

private fun composeTransformer(vararg transformers: Transformer<Any, Any>): Transformer<Any, Any> {
        return Transformer { t ->
            var resultObservable = t
            transformers.forEach {
                resultObservable = resultObservable.compose(it)
            }
            resultObservable
        }
    }

SylvainHocq

fun <TSource> Observable<TSource>.pairWithPrevious()
    : Observable<Pair<TSource?, TSource?>> {
    return this
        .map {
            Pair(null as TSource?, it)
        }
        .scan { acc: Pair<TSource?, TSource?>, current: Pair<TSource?, TSource?> ->
            Pair(acc.second, current.second)
        }
}

SylvainHocq

inline fun <A, B, R> ifNotNull(a: A?, b: B?, code: (A, B) -> R) {
    if (a != null && b != null) {
        code(a, b)
    }
}

inline fun <A, B, C, R> ifNotNull(a: A?, b: B?, c: C?, code: (A, B, C) -> R) {
    if (a != null && b != null && c != null) {
        code(a, b, c)
    }