added more support api elements

Author: holgerbrandl

src/main/kotlin/kscript/FileUtil.kt

@@ -1,7 +1,36 @@
 package kscript
 
+import java.io.*
+import java.util.zip.GZIPOutputStream
+
 /**
  * Helpers to deal with files in kscript applications
  *
  * @author Holger Brandl
  */
+
+
+operator fun File.div(childName: String): File {
+    return this.resolve(childName)
+}
+
+
+//https://dzone.com/articles/readingwriting-compressed-and
+/** Save a list of items into a file. Output can be option ally zipped and a the stringifying operation can be changed from toString to custom operation if needed. */
+fun <T> Iterable<T>.saveAs(f: File,
+                           transform: (T) -> String = { it.toString() },
+                           separator: Char = '\n',
+                           overwrite: Boolean = true,
+                           compress: Boolean = f.name.let { it.endsWith(".zip") || it.endsWith(".gz") }) {
+
+    // ensure that file is not yet there or overwrite flag is set
+    require(!f.isFile || overwrite) { "$f is present already. Use overwrite=true to enforce file replacement." }
+
+    val p = if (!compress) PrintWriter(f) else BufferedWriter(OutputStreamWriter(GZIPOutputStream(FileOutputStream(f))))
+
+    toList().forEach { p.write(transform(it) + separator) }
+
+    p.close()
+}
+
+

src/main/kotlin/kscript/StreamUtil.kt

@@ -1,46 +1,37 @@
 package kscript
 
+import java.io.BufferedReader
 import java.io.File
+import java.io.FileReader
 import kotlin.system.exitProcess
 
 
-// todo maybe  it should also become part of the kscript code repository once ready
-
 // for top-level vs member extensions see https://kotlinlang.org/docs/reference/extensions.html#scope-of-extensions
 //object KscriptHelpers {}
 
 val stdin = generateSequence() { readLine() }
 
-fun Sequence<String>.print() = forEach { println(it) }
 
+/** Read lines stdin or a file argument. Example 'argLines(1).map { it+"foo"}'. could be used either with "-" or file argument. */
+fun argLines(arg: String, stdinNames: List<String> = listOf("-", "stdin")): Sequence<String> {
+    if (stdinNames.contains(arg)) return stdin
 
-fun processStdin(trafo: (String) -> String) {
-    generateSequence() { readLine() }.map {
-        println(trafo(it))
-    }
-}
+    val inputFile = File(arg)
 
-@Deprecated("use mapLines instead")
-fun File.processLines(trafo: (String) -> String) {
-    useLines {
-        it.map { println(trafo(it)) }
-    }
-}
+    stopIfNot(inputFile.canRead()) { "Can not read from '${arg}'" }
 
-fun <T> File.mapLines(trafo: (String) -> T) {
-    return useLines {
-        it.map { trafo(it) }
-    }
+    // not we don't close the buffer with this approach
+    //    BufferedReader(FileReader(inputFile )).use { return it }
+    return BufferedReader(FileReader(inputFile)).lineSequence()
 }
 
-fun String.processLines(trafo: (String) -> String) {
-    split("\n").map { println(trafo(it)) }
-}
 
 
-public inline fun stopIfNot(value: Boolean, lazyMessage: () -> Any): Unit {
-    if (!value) {
-        System.err.println("ERROR: " + lazyMessage().toString())
-        exitProcess(1)
+fun Sequence<String>.print() = forEach { println(it) }
+
+
+fun processStdin(trafo: (String) -> String) {
+    generateSequence() { readLine() }.map {
+        println(trafo(it))
     }
-}
+}

src/main/kotlin/kscript/Support.kt

@@ -0,0 +1,17 @@
+package kscript
+
+import kotlin.system.exitProcess
+
+/**
+ * @author Holger Brandl
+ */
+
+
+fun foo() = "1"
+
+public inline fun stopIfNot(value: Boolean, lazyMessage: () -> Any) {
+    if (!value) {
+        System.err.println("[ERROR] " + lazyMessage().toString())
+        exitProcess(1)
+    }
+}