2016 Update

Task/Arithmetic-evaluation/Elena/arithmetic-evaluation.elena

@@ -1,6 +1,7 @@
-#define system.
-#define system'routines.
-#define extensions.
+#import system.
+#import system'routines.
+#import extensions.
+#import extensions'text.
 
 #class Token
 {
@@ -9,7 +10,7 @@
 
     #constructor new &level:aLevel
     [
-        theValue := String new.
+        theValue := StringWriter new.
         theLevel := aLevel + 9.
     ]
 
@@ -17,10 +18,10 @@
 
     #method append : aChar
     [
-        theValue += aChar.
+        theValue << aChar.
     ]
 
-    #method number = theValue value toReal.
+    #method number = theValue get toReal.
 }
 
 #class Node
@@ -100,8 +101,6 @@
     #method number => theTop.
 }
 
-// --- States ---
-
 #symbol operatorState = (:ch)
 [
     ch =>
@@ -219,7 +218,7 @@
 
     #method append:ch
     [
-        ((ch >= 48) and:(ch < 58))
+        ((ch >= #48) and:(ch < #58))
             ? [ theToken append:ch. ]
             ! [ #throw InvalidArgumentException new &message:"Invalid expression". ].
     ]
@@ -320,11 +319,13 @@
     #var aText := String new.
     #var aParser := Parser new.
 
-    [ (aText << console readLine) length > 0] doWhile:
+    [ console readLine save &to:aText length > 0] doWhile:
     [
         console writeLine:"=" :(aParser run:aText)
             | if &Error:e [
                     console writeLine:"Invalid Expression".
                 ].
+
+        aText clear.
     ].
 ].