fix(rules): Use true/false, not yes/no

Although `yes` and `no` are recognized as booleans by the pyyaml parser,
the correct keywords are `true` and `false` (as highlighted by the newly
added `truthy` rule).

This commit replaces the use of `yes`/`no` by `true`/`false` and
advertise it in the docs, but also makes sure this change is
backward-compatible (so that `yes` and `no` still work).

yamllint/conf/default.yaml

@@ -16,14 +16,14 @@ rules:
     max-spaces-after: 1
   comments:
     level: warning
-    require-starting-space: yes
+    require-starting-space: true
     min-spaces-from-content: 2
   comments-indentation:
     level: warning
   document-end: disable
   document-start:
     level: warning
-    present: yes
+    present: true
   empty-lines:
     max: 2
     max-start: 0
@@ -32,13 +32,13 @@ rules:
     max-spaces-after: 1
   indentation:
     spaces: consistent
-    indent-sequences: yes
-    check-multi-line-strings: no
+    indent-sequences: true
+    check-multi-line-strings: false
   key-duplicates: enable
   line-length:
     max: 80
-    allow-non-breakable-words: yes
-    allow-non-breakable-inline-mappings: no
+    allow-non-breakable-words: true
+    allow-non-breakable-inline-mappings: false
   new-line-at-end-of-file: enable
   new-lines:
     type: unix

yamllint/conf/relaxed.yaml

@@ -25,5 +25,5 @@ rules:
     indent-sequences: consistent
   line-length:
     level: warning
-    allow-non-breakable-inline-mappings: yes
+    allow-non-breakable-inline-mappings: true
   truthy: disable

yamllint/rules/comments.py

@@ -20,14 +20,14 @@ Use this rule to control the position and formatting of comments.
 .. rubric:: Options
 
 * Use ``require-starting-space`` to require a space character right after the
-  ``#``. Set to ``yes`` to enable, ``no`` to disable.
+  ``#``. Set to ``true`` to enable, ``false`` to disable.
 * ``min-spaces-from-content`` is used to visually separate inline comments from
   content. It defines the minimal required number of spaces between a comment
   and its preceding content.
 
 .. rubric:: Examples
 
-#. With ``comments: {require-starting-space: yes}``
+#. With ``comments: {require-starting-space: true}``
 
    the following code snippet would **PASS**:
    ::

yamllint/rules/document_end.py

@@ -19,12 +19,12 @@ Use this rule to require or forbid the use of document end marker (``...``).
 
 .. rubric:: Options
 
-* Set ``present`` to ``yes`` when the document end marker is required, or to
-  ``no`` when it is forbidden.
+* Set ``present`` to ``true`` when the document end marker is required, or to
+  ``false`` when it is forbidden.
 
 .. rubric:: Examples
 
-#. With ``document-end: {present: yes}``
+#. With ``document-end: {present: true}``
 
    the following code snippet would **PASS**:
    ::
@@ -49,7 +49,7 @@ Use this rule to require or forbid the use of document end marker (``...``).
     - is: another one
     ...
 
-#. With ``document-end: {present: no}``
+#. With ``document-end: {present: false}``
 
    the following code snippet would **PASS**:
    ::

yamllint/rules/document_start.py

@@ -19,12 +19,12 @@ Use this rule to require or forbid the use of document start marker (``---``).
 
 .. rubric:: Options
 
-* Set ``present`` to ``yes`` when the document start marker is required, or to
-  ``no`` when it is forbidden.
+* Set ``present`` to ``true`` when the document start marker is required, or to
+  ``false`` when it is forbidden.
 
 .. rubric:: Examples
 
-#. With ``document-start: {present: yes}``
+#. With ``document-start: {present: true}``
 
    the following code snippet would **PASS**:
    ::
@@ -45,7 +45,7 @@ Use this rule to require or forbid the use of document start marker (``---``).
     - this
     - is: another one
 
-#. With ``document-start: {present: no}``
+#. With ``document-start: {present: false}``
 
    the following code snippet would **PASS**:
    ::

yamllint/rules/indentation.py

@@ -25,12 +25,12 @@ Use this rule to control the indentation.
   same within the file.
 * ``indent-sequences`` defines whether block sequences should be indented or
   not (when in a mapping, this indentation is not mandatory -- some people
-  perceive the ``-`` as part of the indentation). Possible values: ``yes``,
-  ``no``, ``whatever`` and ``consistent``. ``consistent`` requires either all
-  block sequences to be indented, or none to be. ``whatever`` means either
+  perceive the ``-`` as part of the indentation). Possible values: ``true``,
+  ``false``, ``whatever`` and ``consistent``. ``consistent`` requires either
+  all block sequences to be indented, or none to be. ``whatever`` means either
   indenting or not indenting individual block sequences is OK.
 * ``check-multi-line-strings`` defines whether to lint indentation in
-  multi-line strings. Set to ``yes`` to enable, ``no`` to disable.
+  multi-line strings. Set to ``true`` to enable, ``false`` to disable.
 
 .. rubric:: Examples
 
@@ -99,7 +99,7 @@ Use this rule to control the indentation.
       Russian:
           dolls
 
-#. With ``indentation: {spaces: 2, indent-sequences: no}``
+#. With ``indentation: {spaces: 2, indent-sequences: false}``
 
    the following code snippet would **PASS**:
    ::
@@ -152,7 +152,7 @@ Use this rule to control the indentation.
       - spaghetti
       - sauce
 
-#. With ``indentation: {spaces: 4, check-multi-line-strings: yes}``
+#. With ``indentation: {spaces: 4, check-multi-line-strings: true}``
 
    the following code snippet would **PASS**:
    ::

yamllint/rules/line_length.py

@@ -22,7 +22,7 @@ Use this rule to set a limit to lines length.
 * ``max`` defines the maximal (inclusive) length of lines.
 * ``allow-non-breakable-words`` is used to allow non breakable words (without
   spaces inside) to overflow the limit. This is useful for long URLs, for
-  instance. Use ``yes`` to allow, ``no`` to forbid.
+  instance. Use ``true`` to allow, ``false`` to forbid.
 * ``allow-non-breakable-inline-mappings`` implies ``allow-non-breakable-words``
   and extends it to also allow non-breakable words in inline mappings.
 
@@ -44,7 +44,7 @@ Use this rule to set a limit to lines length.
       Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
       tempor incididunt ut labore et dolore magna aliqua.
 
-#. With ``line-length: {max: 60, allow-non-breakable-words: yes}``
+#. With ``line-length: {max: 60, allow-non-breakable-words: true}``
 
    the following code snippet would **PASS**:
    ::
@@ -68,15 +68,15 @@ Use this rule to set a limit to lines length.
 
     - foobar: http://localhost/very/very/very/very/very/very/very/very/long/url
 
-#. With ``line-length: {max: 60, allow-non-breakable-words: yes,
-   allow-non-breakable-inline-mappings: yes}``
+#. With ``line-length: {max: 60, allow-non-breakable-words: true,
+   allow-non-breakable-inline-mappings: true}``
 
    the following code snippet would **PASS**:
    ::
 
     - foobar: http://localhost/very/very/very/very/very/very/very/very/long/url
 
-#. With ``line-length: {max: 60, allow-non-breakable-words: no}``
+#. With ``line-length: {max: 60, allow-non-breakable-words: false}``
 
    the following code snippet would **FAIL**:
    ::