add .compact() to set non-compacting for sequence/mapping within sequence0.15.73

7 files changed, 139 insertions, 47 deletions

diff --git a/CHANGES b/CHANGES
index cb6ee69..be3d466 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,8 @@
+[0, 15, 73]: 2018-10-16
+  - fix irregular output on pre-comment in sequence within sequence (reported
+    by `Thorsten Kampe <https://bitbucket.org/thorstenkampe/>`__)
+  - allow non-compact (i.e. next line) dumping sequence/mapping within sequence.
+
 [0, 15, 72]: 2018-10-06
   - fix regression on explicit 1.1 loading with the C based scanner/parser
     (reported by `Tomas Vavra <https://bitbucket.org/xtomik/>`__)
diff --git a/README.rst b/README.rst
index f466c7f..b40e3b4 100644
--- a/README.rst
+++ b/README.rst
@@ -4,8 +4,8 @@ ruamel.yaml
 
 ``ruamel.yaml`` is a YAML 1.2 loader/dumper package for Python.
 
-:version:       0.15.72
-:updated:       2018-10-06
+:version:       0.15.73
+:updated:       2018-10-16
 :documentation: http://yaml.readthedocs.io
 :repository:    https://bitbucket.org/ruamel/
 :pypi:          https://pypi.org/project/ruamel.yaml/
@@ -54,6 +54,11 @@ ChangeLog
 
 .. should insert NEXT: at the beginning of line for next key (with empty line)
 
+0.15.73 (2018-10-16):
+  - fix irregular output on pre-comment in sequence within sequence (reported
+    by `Thorsten Kampe <https://bitbucket.org/thorstenkampe/>`__)
+  - allow non-compact (i.e. next line) dumping sequence/mapping within sequence.
+
 0.15.72 (2018-10-06):
   - fix regression on explicit 1.1 loading with the C based scanner/parser
     (reported by `Tomas Vavra <https://bitbucket.org/xtomik/>`__)
diff --git a/__init__.py b/__init__.py
index b9a3a44..e68a11f 100644
--- a/__init__.py
+++ b/__init__.py
@@ -7,8 +7,8 @@ if False:  # MYPY
 
 _package_data = dict(
     full_package_name='ruamel.yaml',
-    version_info=(0, 15, 72),
-    __version__='0.15.72',
+    version_info=(0, 15, 73),
+    __version__='0.15.73',
     author='Anthon van der Neut',
     author_email='a.van.der.neut@ruamel.eu',
     description='ruamel.yaml is a YAML parser/emitter that supports roundtrip preservation of comments, seq/map flow style, and map key order',  # NOQA
diff --git a/_doc/_static/pypi.svg b/_doc/_static/pypi.svg
index 19b9de5..4b0bd1b 100644
--- a/_doc/_static/pypi.svg
+++ b/_doc/_static/pypi.svg
@@ -1 +1 @@
-<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="86" height="20"><linearGradient id="b" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient><clipPath id="a"><rect width="86" height="20" rx="3" fill="#fff"/></clipPath><g clip-path="url(#a)"><path fill="#555" d="M0 0h33v20H0z"/><path fill="#007ec6" d="M33 0h53v20H33z"/><path fill="url(#b)" d="M0 0h86v20H0z"/></g><g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="110"> <text x="175" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="230">pypi</text><text x="175" y="140" transform="scale(.1)" textLength="230">pypi</text><text x="585" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="430">0.15.72</text><text x="585" y="140" transform="scale(.1)" textLength="430">0.15.72</text></g> </svg>
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="86" height="20"><linearGradient id="b" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient><clipPath id="a"><rect width="86" height="20" rx="3" fill="#fff"/></clipPath><g clip-path="url(#a)"><path fill="#555" d="M0 0h33v20H0z"/><path fill="#007ec6" d="M33 0h53v20H33z"/><path fill="url(#b)" d="M0 0h86v20H0z"/></g><g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="110"> <text x="175" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="230">pypi</text><text x="175" y="140" transform="scale(.1)" textLength="230">pypi</text><text x="585" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="430">0.15.73</text><text x="585" y="140" transform="scale(.1)" textLength="430">0.15.73</text></g> </svg>
diff --git a/_doc/example.ryd b/_doc/example.ryd
index 5df1d5c..c8e1c5d 100644
--- a/_doc/example.ryd
+++ b/_doc/example.ryd
@@ -125,52 +125,114 @@ both mappings and sequences. For sequences the indent is counted to the
 beginning of the scalar, with the dash taking the first position of the
 indented "space".
 
-The following program with three dumps::
+You can change this default indentation by e.g. using ``yaml.indent()``:
+
+
 --- !python |
-  import sys
-  from ruamel.yaml import YAML
 
-  data = {1: {1: [{1: 1, 2: 2}, {1: 1, 2: 2}], 2: 2}, 2: 42}
+import sys
+from ruamel.yaml import YAML
+
+d = dict(a=dict(b=2),c=[3, 4])
+yaml = YAML()
+yaml.dump(d, sys.stdout)
+print('0123456789')
+yaml = YAML()
+yaml.indent(mapping=4, sequence=6, offset=3)
+yaml.dump(d, sys.stdout)
+print('0123456789')
 
-  yaml = YAML()
-  yaml.explicit_start = True
-  yaml.dump(data, sys.stdout)
-  yaml.indent(sequence=4, offset=2)
-  yaml.dump(data, sys.stdout)
 
+--- !stdout |
+
+giving::
+
+
+--- |
+
+If a block sequence or block mapping is the element of a sequence, the
+are, by default, displayed `compact
+<http://yaml.org/spec/1.2/spec.html#id2797686>`__ notation. This means
+that the dash of the "parent" sequence is on the same line as the
+first element resp. first key/value pair of the child collection.
+
+If you want either or both of these (sequence within sequence, mapping
+within sequence) to begin on the next line use ``yaml.compact()``.
+
+
+--- !python |
+
+import sys
+from ruamel.yaml import YAML
+
+d = [dict(b=2), [3, 4]]
+yaml = YAML()
+yaml.dump(d, sys.stdout)
+print('='*15)
+yaml = YAML()
+yaml.compact(seq_seq=False, seq_map=False)
+yaml.dump(d, sys.stdout)
 
-  def sequence_indent_four(s):
-      # this will fail on direclty nested lists: {1; [[2, 3], 4]}
-      levels = []
-      ret_val = ''
-      for line in s.splitlines(True):
-          ls = line.lstrip()
-          indent = len(line) - len(ls)
-          if ls.startswith('- '):
-              if not levels or indent > levels[-1]:
-                  levels.append(indent)
-              elif levels:
-                  if indent < levels[-1]:
-                      levels = levels[:-1]
-              # same -> do nothing
-          else:
-              if levels:
-                  if indent <= levels[-1]:
-                      while levels and indent <= levels[-1]:
-                          levels = levels[:-1]
-          ret_val += '  ' * len(levels) + line
-      return ret_val
 
-  yaml = YAML()
-  yaml.explicit_start = True
-  yaml.dump(data, sys.stdout, transform=sequence_indent_four)
+--- !stdout |
+
+giving::
+
+
+--- | 
+
+------
+
+The following program uses three dumps on the same data, resulting in a stream with 
+three documents:
+
+--- !python |
+import sys
+from ruamel.yaml import YAML
+
+data = {1: {1: [{1: 1, 2: 2}, {1: 1, 2: 2}], 2: 2}, 2: 42}
+
+yaml = YAML()
+yaml.explicit_start = True
+yaml.dump(data, sys.stdout)
+yaml.indent(sequence=4, offset=2)
+yaml.dump(data, sys.stdout)
+
+
+def sequence_indent_four(s):
+    # this will fail on direclty nested lists: {1; [[2, 3], 4]}
+    levels = []
+    ret_val = ''
+    for line in s.splitlines(True):
+        ls = line.lstrip()
+        indent = len(line) - len(ls)
+        if ls.startswith('- '):
+            if not levels or indent > levels[-1]:
+                levels.append(indent)
+            elif levels:
+                if indent < levels[-1]:
+                    levels = levels[:-1]
+            # same -> do nothing
+        else:
+            if levels:
+                if indent <= levels[-1]:
+                    while levels and indent <= levels[-1]:
+                        levels = levels[:-1]
+        ret_val += '  ' * len(levels) + line
+    return ret_val
+
+yaml = YAML()
+yaml.explicit_start = True
+yaml.dump(data, sys.stdout, transform=sequence_indent_four)
+
 --- !stdout |
 gives as output::
 
---- |
-The transform example was inspired by a `question posted by *nowox*
-<https://stackoverflow.com/q/44388701/1307905>`_ on
-StackOverflow.
+--- | 
+
+The transform example, in the last document, was inspired by a
+`question posted by *nowox*
+<https://stackoverflow.com/q/44388701/1307905>`_ on StackOverflow.
 
 -----
 
diff --git a/emitter.py b/emitter.py
index d1e9dee..05311f0 100644
--- a/emitter.py
+++ b/emitter.py
@@ -16,7 +16,7 @@ from ruamel.yaml.events import *  # NOQA
 
 # fmt: off
 from ruamel.yaml.compat import utf8, text_type, PY2, nprint, dbg, DBG_EVENT, \
-    check_anchorname_char, nprintf  # NOQA
+    check_anchorname_char
 # fmt: on
 
 if False:  # MYPY
@@ -156,6 +156,9 @@ class Emitter(object):
         self.column = 0
         self.whitespace = True
         self.indention = True
+        self.compact_seq_seq = True   # dash after dash
+        self.compact_seq_map = True   # key after dash
+        # self.compact_ms = False   # dash after key, only when excplicit key with ?
         self.no_newline = None  # type: Optional[bool]  # set if directly after `- `
 
         # Whether the document requires an explicit document indicator
@@ -404,8 +407,8 @@ class Emitter(object):
             if isinstance(self.event, ScalarEvent):
                 self.expect_scalar()
             elif isinstance(self.event, SequenceStartEvent):
-                nprintf('@', self.indention, self.no_newline, self.column)
-                i2, n2 = self.indention, self.no_newline
+                # nprintf('@', self.indention, self.no_newline, self.column)
+                i2, n2 = self.indention, self.no_newline  # NOQA
                 if self.event.comment:
                     if self.event.flow_style is False and self.event.comment:
                         if self.write_post_comment(self.event):
@@ -596,7 +599,12 @@ class Emitter(object):
 
     def expect_block_sequence(self):
         # type: () -> None
-        indentless = self.mapping_context and not self.indention
+        if self.mapping_context:
+            indentless = not self.indention
+        else:
+            indentless = False
+            if not self.compact_seq_seq and self.column != 0:
+                self.write_line_break()
         self.increase_indent(flow=False, sequence=True, indentless=indentless)
         self.state = self.expect_first_block_sequence_item
 
@@ -629,6 +637,8 @@ class Emitter(object):
 
     def expect_block_mapping(self):
         # type: () -> None
+        if not self.mapping_context and not (self.compact_seq_map or self.column == 0):
+            self.write_line_break()
         self.increase_indent(flow=False, sequence=False)
         self.state = self.expect_first_block_mapping_key
 
@@ -1580,7 +1590,7 @@ class Emitter(object):
     def write_comment(self, comment, pre=False):
         # type: (Any) -> None
         value = comment.value
-        nprintf('{:02d} {:02d} {!r}'.format(self.column, comment.start_mark.column, value))
+        # nprintf('{:02d} {:02d} {!r}'.format(self.column, comment.start_mark.column, value))
         if not pre and value[-1] == '\n':
             value = value[:-1]
         try:
diff --git a/main.py b/main.py
index 140e696..93c688e 100644
--- a/main.py
+++ b/main.py
@@ -146,6 +146,8 @@ class YAML(object):
         self.map_indent = None
         self.sequence_indent = None
         self.sequence_dash_offset = 0
+        self.compact_seq_seq = None
+        self.compact_seq_map = None
 
         self.top_level_colon_align = None
         self.prefix_colon = None
@@ -252,6 +254,10 @@ class YAML(object):
                 if self.sequence_dash_offset is not None:
                     _emitter.sequence_dash_offset = self.sequence_dash_offset
                     # _emitter.block_seq_indent = self.sequence_dash_offset
+                if self.compact_seq_seq is not None:
+                    _emitter.compact_seq_seq = self.compact_seq_seq
+                if self.compact_seq_map is not None:
+                    _emitter.compact_seq_map = self.compact_seq_map
             else:
                 if getattr(self, '_stream', None) is None:
                     # wait for the stream
@@ -709,6 +715,10 @@ class YAML(object):
         # type: (Any) -> None
         self.sequence_dash_offset = val
 
+    def compact(self, seq_seq=None, seq_map=None):
+        self.compact_seq_seq = seq_seq
+        self.compact_seq_map = seq_map
+
 
 class YAMLContextManager(object):
     def __init__(self, yaml, transform=None):