#10 range: over keys of a map

README.asciidoc

@@ -714,7 +714,7 @@ Produces:
 
 === Looping with `range`
 
-The `range` macro substitutes a list of numbers that can be used in `repeat` macros. (Or anywhere else a list of numbers is needed). The start and end values are passed as a list argument. 
+The `range` macro substitutes a list of numbers that can be used in `repeat` macros. (Or anywhere else a list of numbers is needed). The start and end values are passed as a list argument. The range can count up or down, always by one. 
 
 [source, YAML]
 ----
@@ -723,6 +723,28 @@ range: [3,5]
 
 Produces `[3,4,5]`
 
+`range` also accepts a map object, in which case it expands the sequence of map keys. For example
+
+[source, YAML]
+----
+- define: {map: {ra: 879, rb: 662}}
+- range: map
+----
+
+Produces `[ra, rb]`. This can then be used in repeat to loop over the items in a map. Dot notation is used to expand individual members of the map. 
+For example here the loop variable is set to `ra` then `rb` which `map.keyz` resolves to `879` and `662`:
+
+[source, YAML]
+----
+repeat:
+  for: keyz
+  in: {range: map}
+  body:
+    map.keyz
+----
+
+Be aware that map keys in data (such as `ra`) might conflict with already defined variables.   
+
 === Combining Lists with `flatten`
 
 Sometimes you need to combine lists, perhaps from different macro expansions. The `flatten` macro combines multiple lists into a single, flat, list. The flattening is recursive. Syntax:

doc/README.html

@@ -1523,14 +1523,35 @@ <h3 id="_looping_with_code_repeat_code">Looping with <code>repeat</code></h3>
 </div>
 <div class="sect2">
 <h3 id="_looping_with_code_range_code">Looping with <code>range</code></h3>
-<div class="paragraph"><p>The <code>range</code> macro substitutes a list of numbers that can be used in <code>repeat</code> macros. (Or anywhere else a list of numbers is needed). The start and end values are passed as a list argument.</p></div>
+<div class="paragraph"><p>The <code>range</code> macro substitutes a list of numbers that can be used in <code>repeat</code> macros. (Or anywhere else a list of numbers is needed). The start and end values are passed as a list argument. The range can count up or down, always by one.</p></div>
 <div class="listingblock">
 <div class="content"><!-- Generator: GNU source-highlight 3.1.8
 by Lorenzo Bettini
 http://www.lorenzobettini.it
 http://www.gnu.org/software/src-highlite -->
 <pre><tt><span style="color: #009900">range</span><span style="color: #990000">:</span> [<span style="color: #993399">3</span>,<span style="color: #993399">5</span>]</tt></pre></div></div>
 <div class="paragraph"><p>Produces <code>[3,4,5]</code></p></div>
+<div class="paragraph"><p><code>range</code> also accepts a map object, in which case it expands the sequence of map keys. For example</p></div>
+<div class="listingblock">
+<div class="content"><!-- Generator: GNU source-highlight 3.1.8
+by Lorenzo Bettini
+http://www.lorenzobettini.it
+http://www.gnu.org/software/src-highlite -->
+<pre><tt><span style="color: #990000">- </span><span style="color: #009900">define</span><span style="color: #990000">:</span> {map: {ra: <span style="color: #993399">879</span>, rb: <span style="color: #993399">662</span>}}
+<span style="color: #990000">- </span><span style="color: #009900">range</span><span style="color: #990000">:</span> map</tt></pre></div></div>
+<div class="paragraph"><p>Produces <code>[ra, rb]</code>. This can then be used in repeat to loop over the items in a map. Dot notation is used to expand individual members of the map.
+For example here the loop variable is set to <code>ra</code> then <code>rb</code> which <code>map.keyz</code> resolves to <code>879</code> and <code>662</code>:</p></div>
+<div class="listingblock">
+<div class="content"><!-- Generator: GNU source-highlight 3.1.8
+by Lorenzo Bettini
+http://www.lorenzobettini.it
+http://www.gnu.org/software/src-highlite -->
+<pre><tt><span style="color: #009900">repeat</span><span style="color: #990000">:</span>
+<span style="color: #990000">  </span><span style="color: #009900">for</span><span style="color: #990000">:</span> keyz
+<span style="color: #990000">  </span><span style="color: #009900">in</span><span style="color: #990000">:</span> {range: map}
+<span style="color: #990000">  </span><span style="color: #009900">body</span><span style="color: #990000">:</span>
+    map.keyz</tt></pre></div></div>
+<div class="paragraph"><p>Be aware that map keys in data (such as <code>ra</code>) might conflict with already defined variables.</p></div>
 </div>
 <div class="sect2">
 <h3 id="_combining_lists_with_code_flatten_code">Combining Lists with <code>flatten</code></h3>
@@ -1895,7 +1916,7 @@ <h3 id="_updating_this_document">Updating This Document</h3>
 <div id="footer-text">
 Version 0.2<br />
 Last updated
- 2019-06-11 15:34:25 AEST
+ 2019-06-12 12:21:14 AEST
 </div>
 </div>
 </body>

src/yamp.py

@@ -396,19 +396,43 @@ def plus_builtin(tree, args, bindings):
         sum += item
     return sum
 
+def str_2_int(x):
+  """
+  Because idigit() doesnt deal with +- 
+  """
+  if type(x) != str and type(x) != type(1):
+      return None, False
+  try:
+      x = int(x)
+      return x, True
+  except ValueError:
+      return None, False
+
 def range_builtin(tree, statement, bindings):
     """
     :return: a list from  statement[0] to statement[1]
     """
     if not statement:
-       raise(YampException('Syntax error was expecting integers list in {}, got {}'.format(tree, statement)))
-    validate_params(tree, {'range': None}, statement, [1,2])
-    start = str(expand(statement[0], bindings))
-    end = str(expand(statement[1], bindings))
-    for item in [start, end]:
-        if not item.isdigit():
-            raise(YampException('Syntax error was expecting integer range in {}, got {}'.format(tree, item)))
-    return list(range(int(start), int(end)+1))
+       raise(YampException('range: was expecting map or integer sequence in {}'.format(tree)))
+    if type(statement) == list:
+        if len(statement) != 2:
+           raise(YampException('range: {} is not a sequence of two'.format(tree)))
+        start, sok = str_2_int(statement[0])
+        end, eok = str_2_int(statement[1])
+        if not sok or not eok: 
+            raise(YampException('range: {} is not an integer in {}'.format(statement, tree)))
+        if start < end:
+          result = list(range(start, end+1))
+        else:
+          result = list(range(start, end-1, -1))
+        if len(result) == 0:
+            raise(YampException('range: empty range in {}'.format(tree)))
+        return result
+    elif type(statement) == dict:
+        return list(statement.keys())
+    else:
+       raise(YampException('Syntax error was expecting map or integer sequence in {}, got {}'.format(tree, statement)))
+
 
 def flatten_builtin(tree, args, bindings):
     """

test/all-examples.yaml

@@ -31,6 +31,7 @@ include:
   - ../examples/multi_define.yaml
   - ../examples/python.yaml
   - ../examples/quote.yaml
+  - ../examples/range.yaml
   - ../examples/readme.yaml
   - ../examples/recursive.yaml
   - ../examples/repeat.yaml

test/fixtures/all-examples.output.yaml

@@ -295,6 +295,31 @@ webserver:
 - - 333
   - 22
 ---
+- '*************** File: range.yaml *****************'
+---
+- - 1
+  - 2
+- - 1
+  - 2
+- - -2
+  - -1
+---
+- - 1
+  - 0
+- - 1
+  - 0
+- - -1
+  - 0
+---
+ra: 879
+rb: 662
+---
+- ra
+- rb
+---
+- - 879
+- - 662
+---
 - '*************** File: readme.yaml *****************'
 ---
 - Hello: World

test/test_expand_01.py

@@ -665,7 +665,29 @@ def testValidateKeys(self):
         self.try_validate_keys_error("Unexpected", [('a',)], {'a': None, 'b': None})
         self.try_validate_keys_error("Unexpected", [('a',)], {'b': None})
 
-
+    def teststr_2_int_OK(self):
+        self.assertEquals((2, True), (str_2_int(2)))
+        self.assertEquals((2, True), (str_2_int("2")))
+        self.assertEquals((2, True), (str_2_int("+2")))
+        self.assertEquals((-2, True), (str_2_int("-2")))
+
+    def teststr_2_int_bad(self):
+        self.assertEquals((None, False), (str_2_int((2,))))
+        self.assertEquals((None, False), (str_2_int([2])))
+        self.assertEquals((None, False), (str_2_int({"x": 3})))
+        self.assertEquals((None, False), (str_2_int(2.3)))
+        self.assertEquals((None, False), (str_2_int("x")))
+
+    def test_range_builtin_ok(self):
+        self.assertEquals([3,2,1],range_builtin({ "range:" : [3,1]}, [3,1], {}))
+
+    def test_range_builtin_bad(self):
+        with self.assertRaises(Exception) as context:
+            range_builtin({ "range:" : None}, None, {})
+        with self.assertRaises(Exception) as context:
+            range_builtin({ "range:" : [1]}, [1], {})
+        with self.assertRaises(Exception) as context:
+            range_builtin({ "range:" :[1, "x"]}, [1, "x"], {})
 
     def runFileRegression(self, file_to_test, fixture):
         tempout = tempfile.mkstemp()