Start REPL on no args in dotty script, fix backticks

Author: felixmulder

bin/dotc

@@ -3,12 +3,12 @@
 # it's based on miniboxing script and paulp's launcher script
 
 # Try to autodetect real location of the script
-DOTTY_ROOT="`readlink \"$0\"`"             #  relative, symbolic links resolved
+DOTTY_ROOT="$(readlink "$0")"              #  relative, symbolic links resolved
 if [[ "$DOTTY_ROOT" == "" ]]; then
   DOTTY_ROOT="$0"
 fi
-DOTTY_ROOT="`dirname \"$DOTTY_ROOT\"`"
-DOTTY_ROOT="`( cd \"$DOTTY_ROOT\" >& /dev/null && pwd )`/.."  # absolute
+DOTTY_ROOT="$(dirname "$DOTTY_ROOT")"
+DOTTY_ROOT="$( cd "$DOTTY_ROOT" >& /dev/null && pwd )/.."  # absolute
 
 # Finds in dotty build file a line containing PATTERN
 # returns last "" escaped string in this line

bin/dotty renamed to bin/dottyr

@@ -1,12 +1,12 @@
 #!/bin/bash
 
 # Try to autodetect real location of the script
-DOTTY_ROOT="`readlink \"$0\"`"             #  relative, symbolic links resolved
+DOTTY_ROOT="$(readlink "$0")"              #  relative, symbolic links resolved
 if [[ "$DOTTY_ROOT" == "" ]]; then
   DOTTY_ROOT="$0"
 fi
-DOTTY_ROOT="`dirname \"$DOTTY_ROOT\"`"
-DOTTY_ROOT="`( cd \"$DOTTY_ROOT\" && pwd )`/.."  # absolute
+DOTTY_ROOT="$(dirname "$DOTTY_ROOT")"
+DOTTY_ROOT="$( cd "$DOTTY_ROOT" && pwd )/.."  # absolute
 
 # CLASS_PATH is derived from the DOTTY_ROOT
 CLASS_PATH="-J-Xbootclasspath/a:.:$DOTTY_ROOT/target/scala-2.11/classes/"
@@ -16,10 +16,8 @@ function runMain {
 }
 
 if [ -z "$1" ]; then
-    echo "usage: $0 MainClass args"
-    echo ""
-    echo "       missing class argument"
-    exit 1
+    echo "Starting dotty REPL..."
+    eval "$DOTTY_ROOT/bin/dotc -repl"
 else
     runMain "$@"
 fi