scripts: merge removeAnchors.sh and resetSolutions.sh

Keeping it all in a single `scripts/prepareExercises.sh` avoids
duplication.

Also remove the complex file finding; simply getting all source
files within the `exercises` directory is a perfect fit for what is
needed. This fixes Issue purescript-contrib#430.

scripts/prepareExercises.sh

@@ -0,0 +1,77 @@
+#! /bin/sh
+
+# This script removes meta information that is not intended for readers of the book
+# from the exercises
+
+all=
+none=1
+removeAnchors=
+removeSolutions=
+
+show_help () {
+    cat <<EOF >&2
+Usage: $0 [anchors] [solutions] [all]
+
+Prepare code in exercises/* for reading. If no option is specified,
+`all` is used by default.
+
+OPTIONS
+    all         Perform all tasks
+    anchors     Remove code anchors to improve readability
+    solutions   Remove exercise solutions
+
+EOF
+}
+
+for opt in "$@"; do
+    # Reset none, since some action was requested
+    none=
+    case $opt in
+        all )
+            all=1
+            ;;
+        help )
+            show_help
+            exit 0
+            ;;
+        anchors )
+            removeAnchors=1
+            ;;
+        solutions )
+            removeSolutions=1
+            ;;
+        * )
+            show_help
+            exit 1
+            ;;
+    esac
+done
+
+if [ x$all != x -o x$none != x ]; then
+    # Either 'all' was specified, or default to all actions
+    removeAnchors=1
+    removeSolutions=1
+fi
+
+# Echo commands to shell
+set -x
+# Exit on first failure
+set -e
+
+# All .purs & .js files of chapter exercises.
+FILES=$(find exercises \( -name '*.purs' -o -name '*.js' \) -print)
+
+for f in $FILES; do
+  # Delete lines starting with an 'ANCHOR' comment
+  [ -n $removeAnchors ] && perl -ni -e 'print if !/^\s*(--|\/\/) ANCHOR/' $f
+
+  # Delete lines with a note to delete them
+  [ -n $removeSolutions ] && perl -ni -e 'print if !/This line should have been automatically deleted/' $f
+done
+
+# Move 'no-peeking' sources out of the compilation path
+if [ -n $removeSolutions ]; then
+    for d in exercises/chapter*; do
+        [ -d "$d/test/no-peeking" ] && mv "$d/test/no-peeking" "$d"
+    done
+fi

text/chapter2.md

@@ -24,12 +24,11 @@ Now that you've installed the necessary development tools, clone this book's rep
 git clone https://github.com/purescript-contrib/purescript-book.git
 ```
 
-The book repo contains PureScript example code and unit tests for the exercises that accompany each chapter. There's some initial setup required to reset the exercise solutions so they are ready to be solved by you. Use the `resetSolutions.sh` script to simplify this process. While at it, you should also strip out all the anchor comments with the `removeAnchors.sh` script (these anchors are used for copying code snippets into the book's rendered markdown, and you probably don't need this clutter in your local repo):
+The book repo contains PureScript example code and unit tests for the exercises that accompany each chapter. There's some initial setup required to reset the exercise solutions so they are ready to be solved by you. Use the `prepareExercises.sh` script to simplify this process:
 
 ```sh
 cd purescript-book
-./scripts/resetSolutions.sh
-./scripts/removeAnchors.sh
+./scripts/prepareExercises.sh
 git add .
 git commit --all --message "Exercises ready to be solved"
 ```