Merge 2b91701 into ce0123f

docs/grammar.md

@@ -824,6 +824,10 @@ specified in brackets (`[ ]`) at the beginning of the rule's definition after
 the rule's name. Currently, they are used to alter parser configuration for
 whitespace handling on the rule level.
 
+Rule modifiers act on the current rule and all rules referenced inside the rule 
+(recursively): unless a refrenced rule has an explicit rule modifier, the currently
+active modifier state is propagated to referenced rules.
+
 There are two rule modifiers at the moment:
 
 * **skipws, noskipws** - are used to enable/disable whitespace skipping during

tests/functional/regressions/test_issue205_skipws_propagation.py

@@ -0,0 +1,84 @@
+from __future__ import unicode_literals
+from textx.metamodel import metamodel_from_str
+
+
+def test_issue205_skipws_propagation1():
+    """
+    Here, we show how the ```skipws``` rule modifier is propagated
+    to all rules used by the rule with the modifier.
+    """
+    mm = metamodel_from_str('''
+        SGroup[skipws]: '<s>' Sentence '</s>';      // skipws active
+        Sentence: /(?i) */ words*=Word /(?i) */;    // skipws active <- SGroup
+        Word: /(?i) */ ('bar' '.' | 'bar' | '.');   // skipws active <- SGroup
+    ''', skipws=False, debug=False)
+
+    m = mm.model_from_str('''<s> bar . </s>''', debug=False)
+    assert 1 == len(m.words)
+    assert 'bar.' == m.words[0]
+
+
+def test_issue205_skipws_propagation2():
+    """
+    Here, we show how the default ```skipws``` rule modifier is used
+    as default (because no modifier is explicitly specified).
+    """
+    mm = metamodel_from_str('''
+        SGroup: '<s>' Sentence '</s>';
+        Sentence: /(?i) */ words*=Word /(?i) */;
+        Word: /(?i) */ ('bar' '.' | 'bar' | '.');
+    ''',
+                            skipws=False,  # default skipws value
+                            debug=False)
+
+    assert 2 == len(mm.model_from_str('''<s> bar . </s>''', debug=False).words)
+    assert 1 == len(mm.model_from_str('''<s> bar. </s>''', debug=False).words)
+
+
+def test_issue205_skipws_propagation3():
+    """
+    Here, we show how a given ```skipws``` rule modifier is overridden
+    by another explicitly specified rule modifier, which stops the
+    propagation: the ```skipws``` rule modifier in ```SGroup``` is
+    overridden by the ```noskipws``` rule modifier of the
+    rule ```Sentence``` (used in ```SGroup```).
+    """
+    mm = metamodel_from_str('''
+        SGroup[skipws]: '<s>' Sentence '</s>';
+        Sentence[noskipws]: /(?i) */ words*=Word /(?i) */;
+        Word: /(?i) */ ('bar' '.' | 'bar' | '.');
+    ''', skipws=False, debug=False)
+
+    assert 2 == len(mm.model_from_str('''<s> bar . </s>''', debug=False).words)
+    assert 1 == len(mm.model_from_str('''<s> bar. </s>''', debug=False).words)
+    assert 1 == len(mm.model_from_str('''<s> bar </s>''', debug=False).words)
+    assert 1 == len(mm.model_from_str('''<s> . </s>''', debug=False).words)
+
+
+def test_issue205_skipws_propagation4():
+    """
+    Here, we show that a rule with the ```noskipws``` rule modifier
+    is able to consume spaces explicitly. Match suppression (-) is
+    employed to exclude these spaces from the target value (this means the
+    ```Word``` does not include the spaces in its value).
+
+    Note: ```skipws``` of Sentence does not consume the spaces between
+    the words, because the [rule modifiers]
+    (http://textx.github.io/textX/stable/grammar/#rule-modifiers)
+    apply immediately. Thus, we need to consume the extra spaces before a word.
+    """
+    mm = metamodel_from_str(r'''
+        Sentence[skipws]: words*=Word;
+        Word[noskipws]: /\s*/- ((ID '.') | ID | '.');
+    ''', skipws=True)
+
+    m = mm.model_from_str('''foo bar .''')
+    assert "foo" == m.words[0]
+    assert "bar" == m.words[1]
+    assert 3 == len(m.words)
+    assert "." == m.words[2]
+
+    m = mm.model_from_str('''foo bar.''')
+    assert "foo" == m.words[0]
+    assert "bar." == m.words[1]
+    assert 2 == len(m.words)