Merge branch 'take_and_skip' of https://github.com/bjorn/wren into bjorn-take_and_skip

src/vm/wren_core.wren

@@ -56,6 +56,10 @@ class Sequence {
 
   map(transformation) { MapSequence.new(this, transformation) }
 
+  skip(count) { SkipSequence.new(this, count) }
+
+  take(count) { TakeSequence.new(this, count) }
+
   where(predicate) { WhereSequence.new(this, predicate) }
 
   reduce(acc, f) {
@@ -112,6 +116,43 @@ class MapSequence is Sequence {
   iteratorValue(iterator) { _fn.call(_sequence.iteratorValue(iterator)) }
 }
 
+class SkipSequence is Sequence {
+  construct new(sequence, count) {
+    _sequence = sequence
+    _count = count
+  }
+
+  iterate(iterator) {
+    if (iterator) {
+      return _sequence.iterate(iterator)
+    } else {
+      iterator = _sequence.iterate(iterator)
+      var count = _count
+      while (count > 0 && iterator) {
+        iterator = _sequence.iterate(iterator)
+        count = count - 1
+      }
+      return iterator
+    }
+  }
+
+  iteratorValue(iterator) { _sequence.iteratorValue(iterator) }
+}
+
+class TakeSequence is Sequence {
+  construct new(sequence, count) {
+    _sequence = sequence
+    _count = count
+  }
+
+  iterate(iterator) {
+    if (!iterator) _taken = 1 else _taken = _taken + 1
+    return _taken > _count ? null : _sequence.iterate(iterator)
+  }
+
+  iteratorValue(iterator) { _sequence.iteratorValue(iterator) }
+}
+
 class WhereSequence is Sequence {
   construct new(sequence, fn) {
     _sequence = sequence

src/vm/wren_core.wren.inc

@@ -58,6 +58,10 @@ static const char* coreModuleSource =
 "\n"
 "  map(transformation) { MapSequence.new(this, transformation) }\n"
 "\n"
+"  skip(count) { SkipSequence.new(this, count) }\n"
+"\n"
+"  take(count) { TakeSequence.new(this, count) }\n"
+"\n"
 "  where(predicate) { WhereSequence.new(this, predicate) }\n"
 "\n"
 "  reduce(acc, f) {\n"
@@ -114,6 +118,43 @@ static const char* coreModuleSource =
 "  iteratorValue(iterator) { _fn.call(_sequence.iteratorValue(iterator)) }\n"
 "}\n"
 "\n"
+"class SkipSequence is Sequence {\n"
+"  construct new(sequence, count) {\n"
+"    _sequence = sequence\n"
+"    _count = count\n"
+"  }\n"
+"\n"
+"  iterate(iterator) {\n"
+"    if (iterator) {\n"
+"      return _sequence.iterate(iterator)\n"
+"    } else {\n"
+"      iterator = _sequence.iterate(iterator)\n"
+"      var count = _count\n"
+"      while (count > 0 && iterator) {\n"
+"        iterator = _sequence.iterate(iterator)\n"
+"        count = count - 1\n"
+"      }\n"
+"      return iterator\n"
+"    }\n"
+"  }\n"
+"\n"
+"  iteratorValue(iterator) { _sequence.iteratorValue(iterator) }\n"
+"}\n"
+"\n"
+"class TakeSequence is Sequence {\n"
+"  construct new(sequence, count) {\n"
+"    _sequence = sequence\n"
+"    _count = count\n"
+"  }\n"
+"\n"
+"  iterate(iterator) {\n"
+"    if (!iterator) _taken = 1 else _taken = _taken + 1\n"
+"    return _taken > _count ? null : _sequence.iterate(iterator)\n"
+"  }\n"
+"\n"
+"  iteratorValue(iterator) { _sequence.iteratorValue(iterator) }\n"
+"}\n"
+"\n"
 "class WhereSequence is Sequence {\n"
 "  construct new(sequence, fn) {\n"
 "    _sequence = sequence\n"