the line number of the yaml file is displayed in the error message (#34)

* lineloader class

* Line Tags in Error Messages!

* pylint

* support extends keyword in root level of yaml file

* cleaning yaml2nxdl folder

* pylint

* tests implemented and PR comments solved

* test_yaml2nxdl updated

* test yaml2nxdl failing

* python version changed in pylint.yml

.github/workflows/pylint.yml

@@ -10,10 +10,10 @@ jobs:
     - uses: actions/checkout@v2
       with:
         lfs: true
-    - name: Set up Python 3.7
+    - name: Set up Python 3.8
       uses: actions/setup-python@v2
       with:
-        python-version: 3.7
+        python-version: 3.8
     - name: Install dependencies
       run: |
         git submodule sync --recursive

nexusparser/tools/yaml2nxdl/yaml2nxdl.py

@@ -98,17 +98,25 @@ def yaml2nxdl(input_file: str, verbose: bool):
 application and base are valid categories!'
     assert 'doc' in yml_appdef.keys(), 'Required root-level keyword doc is missing!'
 
-    xml_root.set('extends', 'NXobject')
     xml_root.set('type', 'group')
+
+    if 'extends' in yml_appdef.keys():
+        xml_root.set('extends', yml_appdef['extends'])
+        del yml_appdef['extends']
+    else:
+        xml_root.set('extends', 'NXobject')
+
     if yml_appdef['category'] == 'application':
         xml_root.set('category', 'application')
-        del yml_appdef['category']
     else:
         xml_root.set('category', 'base')
-        del yml_appdef['category']
+    del yml_appdef['category']
 
     if 'symbols' in yml_appdef.keys():
-        yaml2nxdl_forward_tools.xml_handle_symbols(xml_root, yml_appdef['symbols'])
+        yaml2nxdl_forward_tools.xml_handle_symbols(yml_appdef,
+                                                   xml_root,
+                                                   'symbols',
+                                                   yml_appdef['symbols'])
         del yml_appdef['symbols']
 
     assert isinstance(yml_appdef['doc'], str) and yml_appdef['doc'] != '', 'Doc \
@@ -119,9 +127,14 @@ def yaml2nxdl(input_file: str, verbose: bool):
 
     del yml_appdef['doc']
 
-    assert len(yml_appdef.keys()) == 1, 'Accepting at most keywords: category, \
+    root_keys = 0
+    for key in yml_appdef.keys():
+        if '__line__' not in key:
+            root_keys += 1
+
+    assert root_keys == 1, 'Accepting at most keywords: category, \
 doc, symbols, and NX... at root-level!'
-    keyword = list(yml_appdef.keys())[0]  # which is the only one
+    keyword = list(yml_appdef.keys())[0]
     assert (keyword[0:3] == '(NX' and keyword[-1:] == ')' and len(keyword) > 4), 'NX \
 keyword has an invalid pattern, or is too short!'
     xml_root.set('name', keyword[1:-1])