Issue #621. Added the ability to leave the start and end index off of…

… arrays. list[5..] is now valid CoffeeScript, slicing to the end of the array.
jashkenas · Aug 19, 2010 · 4ddd65a · 4ddd65a
1 parent bf6bafa
commit 4ddd65a
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Showing 6 changed files with 142 additions and 101 deletions.
diff --git a/lib/grammar.js b/lib/grammar.js
@@ -307,6 +307,14 @@
         return new RangeNode($2, $5);
       }), o("INDEX_START Expression . . . Expression INDEX_END", function() {
         return new RangeNode($2, $6, true);
+      }), o("INDEX_START Expression . . INDEX_END", function() {
+        return new RangeNode($2, null);
+      }), o("INDEX_START Expression . . . INDEX_END", function() {
+        return new RangeNode($2, null, true);
+      }), o("INDEX_START . . Expression INDEX_END", function() {
+        return new RangeNode(null, $4);
+      }), o("INDEX_START . . . Expression INDEX_END", function() {
+        return new RangeNode(null, $5, true);
       })
     ],
     Array: [

diff --git a/lib/nodes.js b/lib/nodes.js
@@ -692,11 +692,14 @@
     SliceNode.prototype["class"] = 'SliceNode';
     SliceNode.prototype.children = ['range'];
     SliceNode.prototype.compileNode = function(o) {
-      var from, plusPart, to;
-      from = this.range.from.compile(o);
-      to = this.range.to.compile(o);
-      plusPart = this.range.exclusive ? '' : ' + 1';
-      return ".slice(" + (from) + ", " + (to) + (plusPart) + ")";
+      var from, to;
+      from = this.range.from ? this.range.from.compile(o) : '0';
+      to = this.range.to ? this.range.to.compile(o) : '';
+      to += (!to || this.range.exclusive ? '' : ' + 1');
+      if (to) {
+        to = ', ' + to;
+      }
+      return ".slice(" + (from) + (to) + ")";
     };
     return SliceNode;
   })();
@@ -990,8 +993,8 @@
       l = this.variable.properties.length;
       range = this.variable.properties[l - 1].range;
       plus = range.exclusive ? '' : ' + 1';
-      from = range.from.compile(o);
-      to = range.to.compile(o) + ' - ' + from + plus;
+      from = range.from ? range.from.compile(o) : '0';
+      to = range.to ? range.to.compile(o) + ' - ' + from + plus : ("" + (name) + ".length");
       val = this.value.compile(o);
       return "" + (name) + ".splice.apply(" + (name) + ", [" + (from) + ", " + (to) + "].concat(" + (val) + "))";
     };