fix: update Console to use Sys.Console and new effect API

src/monadic-for-yield.md

@@ -61,12 +61,14 @@ Similarly, we can use `forM` to work with the `Result[e, t]` data type. For
 example:
 
 ```flix
-def main(): Result[String, Unit] \ IO = 
+use Sys.Console
+
+def main(): Result[String, Unit] \ IO =
     println("Please enter your first name, last name, and age:");
     forM (
-        fstName <- Console.readLine();
-        lstName <- Console.readLine();
-        ageLine <- Console.readLine();
+        fstName <- Console.readln();
+        lstName <- Console.readln();
+        ageLine <- Console.readln();
         ageNum  <- Int32.parse(10, ageLine)
     ) yield {
         println("Hello ${lstName}, ${fstName}.");
@@ -75,7 +77,7 @@ def main(): Result[String, Unit] \ IO =
 ```
 
 Here `main` prompts the user to enter their first name, last name, and age. Each
-call to `Console.readLine` returns a `Result[String, String]` value which is
+call to `Console.readln` returns a `Result[String, String]` value which is
 either an error or the input string. Thus the local variables `fstName`,
 `lstName`, and `ageLine` are `String`s. We parse `ageLine` into an `Int32` using
 `Int32.parse`, which returns a `Result[String, Int32]` value. If every operation

src/next-steps.md

@@ -8,21 +8,23 @@ UNIX.
 We will use the opportunity to illustrate how to use algebraic effects in Flix.
 
 ```flix
+use Sys.Console
+
 def wc(file: String): Unit \ {Console, FileReadWithResult} = {
        match FileReadWithResult.readLines(file) {
-            case Ok(lines) => 
+            case Ok(lines) =>
                 let totalLines = List.length(lines);
                 let totalWords = List.sumWith(numberOfWords, lines);
                 Console.println("Lines: ${totalLines}, Words: ${totalWords}")
-            case Err(_) => 
+            case Err(_) =>
                 Console.println("Unable to read file: ${file}")
         }
 }
 
-def numberOfWords(s: String): Int32 = 
+def numberOfWords(s: String): Int32 =
      s |> String.words |> List.length
 
-def main(): Unit \ IO = 
+def main(): Unit \ IO =
     run {
         wc("Main.flix")
     } with Console.runWithIO

src/printing-to-stdout.md

@@ -21,15 +21,17 @@ The `println` function is rightfully effectful, hence it cannot be called from a
 pure function. To debug a pure function, use the builtin [debugging
 facilities](./debugging.md).
 
-## The Console Module
+## The Console Effect
 
-The `Console` module defines additional functions for reading from or writing to
-the terminal: 
+The `Console` effect defines operations for reading from and writing to the
+terminal:
 
 ```flix
-mod Console {
-    def print(x: a): Unit \ IO with ToString[a]
-    def println(x: a): Unit \ IO with ToString[a]
-    def readLine(): Result[String, String] \ IO Impure
+eff Console {
+    def readln(): String
+    def print(s: String): Unit
+    def eprint(s: String): Unit
+    def println(s: String): Unit
+    def eprintln(s: String): Unit
 }
 ```