Add new range operators

snap-compile/src/test/java/org/snapscript/compile/ForInLoopTest.java

@@ -1,20 +1,54 @@
 package org.snapscript.compile;
 
-import junit.framework.TestCase;
-
-public class ForInLoopTest extends TestCase {
+public class ForInLoopTest extends ScriptTestCase {
 
    private static final String SOURCE_1 =
    "for(let i in 0..9){\n"+
    "   assert i > -1;\n"+
    "}\n"+
-   "for(var i in 0..9){\n"+
+   "let l = [];\n"+
+   "for(i in 0 .. 9){\n"+
+   "   l.add(i);\n"+
+   "   assert i > -1;\n"+
+   "}\n"+
+   "println(l);\n"+
+   "assert l.length == 10;\n"+
+   "assert l[2] == 2;\n"+
+   "assert l[3] == 3;\n"+
+   "assert l[9] == 9;\n";
+
+   private static final String SOURCE_2 =
+   "for(let i in 0 to 9){\n"+
+    "   assert i > -1;\n"+
+    "}\n"+
+    "let l = [];\n"+
+    "for(var i in 0 to 9){\n"+
+    "   l.add(i);\n"+
+    "   assert i > -1;\n"+
+    "}\n"+
+    "println(l);\n"+
+    "assert l.length == 10;\n"+
+    "assert l[2] == 2;\n"+
+    "assert l[3] == 3;\n"+
+    "assert l[9] == 9;\n";
+
+   private static final String SOURCE_3 =
+   "for(let i in 0 from 9){\n"+
    "   assert i > -1;\n"+
-   "}\n";
-
+   "}\n"+
+   "let l = [];\n"+
+   "for(var i in 0 from 9){\n"+
+   "   l.add(i);\n"+
+   "   assert i > -1;\n"+
+   "}\n"+
+   "println(l);\n"+
+   "assert l.length == 10;\n"+
+   "assert l[0] == 9;\n"+
+   "assert l[9] == 0;\n";
+
    public void testForInLoop() throws Exception {
-      Compiler compiler = ClassPathCompilerBuilder.createCompiler();
-      Executable executable = compiler.compile(SOURCE_1);
-      executable.execute();
+      assertScriptExecutes(SOURCE_1);
+      assertScriptExecutes(SOURCE_2);
+      assertScriptExecutes(SOURCE_3);
    }
 }

snap-parse/src/main/resources/grammar.txt

@@ -38,7 +38,8 @@ variable-reference = {<super> | <this> | <variable>} *( '(' <function-curry>')'
 
 collection-index = <argument>;
 
-range = <argument>'..'<argument>;
+range-operator = {'..' | 'from' | 'to'};
+range = <argument>?_<range-operator>?_<argument>;
 
 constructor = 'new';
 

snap-parse/src/test/java/org/snapscript/parse/ExpressionParseTest.java

@@ -10,6 +10,9 @@ public void testParse() throws Exception {
       SyntaxParser tree = LexerBuilder.create(GRAMMAR_FILE);
 
       assertNotNull(tree);
+      analyze(tree, "0 .. 10", "range");
+      analyze(tree, "0 to 10", "range");
+      analyze(tree, "0 from 10", "range");
       analyze(tree, "let x: (a) = (a) -> a.run();", "declaration-statement");
       analyze(tree, "let x = <T: Runnable>(a: T) -> a.run();", "declaration-statement");
       analyze(tree, "Foo", "alias-name");

snap-tree/src/main/java/org/snapscript/tree/collection/Range.java

@@ -4,15 +4,21 @@
 
 import org.snapscript.core.Evaluation;
 import org.snapscript.core.constraint.Constraint;
+import org.snapscript.core.error.InternalStateException;
 import org.snapscript.core.scope.Scope;
 import org.snapscript.core.variable.Value;
+import org.snapscript.parse.StringToken;
 
 public class Range extends Evaluation {
 
+   private final RangeOperator operator;
+   private final StringToken token;
    private final Evaluation start;
    private final Evaluation finish;
 
-   public Range(Evaluation start, Evaluation finish) {
+   public Range(Evaluation start, StringToken token, Evaluation finish) {
+      this.operator = RangeOperator.resolveOperator(token);
+      this.token = token;
       this.start = start;
       this.finish = finish;
    }
@@ -25,6 +31,9 @@ public void define(Scope scope) throws Exception {
 
    @Override
    public Constraint compile(Scope scope, Constraint left) throws Exception {
+      if(operator == null) {
+         throw new InternalStateException("Illegal " + token + " operator for range");
+      }
       return ITERABLE;
    }
 
@@ -39,7 +48,7 @@ private Sequence create(Scope scope, Value left) throws Exception {
       Value last = finish.evaluate(scope, left);
       long start = first.getLong();
       long finish = last.getLong();
-      
-      return new Sequence(start, finish);
+
+      return new Sequence(start, finish, operator.forward);
    }
 }

snap-tree/src/main/java/org/snapscript/tree/collection/RangeOperator.java

@@ -0,0 +1,44 @@
+package org.snapscript.tree.collection;
+
+import org.snapscript.parse.StringToken;
+
+public enum RangeOperator {
+   DOT("..", true),
+   TO("to", true),
+   FROM("from", false);
+
+   public final String operator;
+   public final boolean forward;
+
+   private RangeOperator(String operator, boolean forward) {
+      this.operator = operator;
+      this.forward = forward;
+   }
+
+   public boolean isForward() {
+      return forward;
+   }
+
+   public boolean isReverse() {
+      return !forward;
+   }
+
+   public static RangeOperator resolveOperator(StringToken token) {
+      if(token != null) {
+         String value = token.getValue();
+
+         for(RangeOperator operator : VALUES) {
+            if (operator.operator.equals(value)) {
+               return operator;
+            }
+         }
+      }
+      return null;
+   }
+
+   private static final RangeOperator[] VALUES = {
+        DOT,
+        TO,
+        FROM
+   };
+}

snap-tree/src/main/java/org/snapscript/tree/collection/Sequence.java

@@ -4,20 +4,22 @@
 
 public class Sequence implements Iterable<Number> {
 
+   private final boolean forward;
    private final long first;
    private final long last;
 
-   public Sequence(long first, long last) {
+   public Sequence(long first, long last, boolean forward) {
+      this.forward = forward;
       this.first = first;
       this.last = last;
    }
 
    @Override
    public Iterator<Number> iterator() {
-      if(first > last) {
-         return new ReverseIterator(first, last);
+      if(forward) {
+         return new ForwardIterator(first, last);
       }
-      return new ForwardIterator(first, last);
+      return new ReverseIterator(last, first);
    }
 
    private static class ForwardIterator implements Iterator<Number> {
@@ -50,10 +52,10 @@ public void remove() {
    }
 
    private static class ReverseIterator implements Iterator<Number> {
-      
+
       private long first;
       private long last;
-      
+
       public ReverseIterator(long first, long last) {
          this.first = first;
          this.last = last;
@@ -71,7 +73,7 @@ public Number next() {
          }
          return null;
       }
-      
+
       @Override
       public void remove() {
          throw new UnsupportedOperationException("Illegal modification of range");