- refactorings

DHParser/VERALTET/transformation_factory.py

+# Transformation factory that can also dispatch on Union typs
+
+def transformation_factory(t=None):
+    """Creates factory functions from transformation-functions that
+    dispatch on the first parameter after the context parameter.
+
+    Decorating a transformation-function that has more than merely the
+    ``node``-parameter with ``transformation_factory`` creates a
+    function with the same name, which returns a partial-function that
+    takes just the context-parameter.
+
+    Additionally, there is some some syntactic sugar for
+    transformation-functions that receive a collection as their second
+    parameter and do not have any further parameters. In this case a
+    list of parameters passed to the factory function will be converted
+    into a collection.
+
+    Main benefit is readability of processing tables.
+
+    Usage:
+        @transformation_factory(AbstractSet[str])
+        def remove_tokens(context, tokens):
+            ...
+      or, alternatively:
+        @transformation_factory
+        def remove_tokens(context, tokens: AbstractSet[str]):
+            ...
+
+    Example:
+        trans_table = { 'expression': remove_tokens('+', '-') }
+      instead of:
+        trans_table = { 'expression': partial(remove_tokens, tokens={'+', '-'}) }
+
+    Parameters:
+        t:  type of the second argument of the transformation function,
+            only necessary if the transformation functions' parameter list
+            does not have type annotations.
+    """
+
+    def decorator(f):
+        sig = inspect.signature(f)
+        params = list(sig.parameters.values())[1:]
+        if len(params) == 0:
+            return f  # '@transformer' not needed w/o free parameters
+        assert t or params[0].annotation != params[0].empty, \
+            "No type information on second parameter found! Please, use type " \
+            "annotation or provide the type information via transfomer-decorator."
+        p1type = t or params[0].annotation
+        p_types = (p1type,)
+        if hasattr(p1type, '_subs_tree'):
+            subs_tree = p1type._subs_tree()
+            if isinstance(subs_tree, Container) and subs_tree[0] is Union:
+                p_types = subs_tree[1:]
+        f = singledispatch(f)
+        for p1type in p_types:
+            if len(params) == 1 and issubclass(p1type, Container) \
+                    and not issubclass(p1type, Text) and not issubclass(p1type, ByteString):
+                def gen_special(*args):
+                    c = set(args) if issubclass(p1type, AbstractSet) else \
+                        list(args) if issubclass(p1type, Sequence) else args
+                    d = {params[0].name: c}
+                    return partial(f, **d)
+
+                f.register(p1type.__args__[0], gen_special)
+
+            def gen_partial(*args, **kwargs):
+                print(f.__name__)
+                d = {p.name: arg for p, arg in zip(params, args)}
+                d.update(kwargs)
+                return partial(f, **d)
+
+            f.register(p1type, gen_partial)
+        return f
+
+    if isinstance(t, type(lambda: 1)):
+        # Provide for the case that transformation_factory has been
+        # written as plain decorator and not as a function call that
+        # returns the decorator proper.
+        func = t
+        t = None
+        return decorator(func)
+    else:
+        return decorator
\ No newline at end of file

DHParser/dsl.py

@@ -75,12 +75,12 @@ from DHParser import logging, is_filename, load_if_file, \\
     Option, NegativeLookbehind, OneOrMore, RegExp, Retrieve, Series, RE, Capture, \\
     ZeroOrMore, Forward, NegativeLookahead, mixin_comment, compile_source, \\
     last_value, counterpart, accumulate, PreprocessorFunc, \\
-    Node, TransformationFunc, TransformationDict, TRUE_CONDITION, \\
+    Node, TransformationFunc, TransformationDict, \\
     traverse, remove_children_if, merge_children, is_anonymous, \\
-    reduce_single_child, replace_by_single_child, replace_or_reduce, remove_whitespace, \\
+    content_from_child, replace_by_child, replace_or_reduce, remove_whitespace, \\
     remove_expendables, remove_empty, remove_tokens, flatten, is_whitespace, \\
     is_empty, is_expendable, collapse, replace_content, WHITESPACE_PTYPE, TOKEN_PTYPE, \\
-    remove_parser, remove_content, remove_brackets, replace_parser, \\
+    remove_nodes, remove_content, remove_brackets, replace_parser, \\
     keep_children, is_one_of, has_content, apply_if, remove_first, remove_last
 '''
 

DHParser/ebnf.py

@@ -27,7 +27,7 @@ from DHParser.parser import Grammar, mixin_comment, nil_preprocessor, Forward, R
 from DHParser.syntaxtree import Node, TransformationFunc, WHITESPACE_PTYPE, TOKEN_PTYPE
 from DHParser.toolkit import load_if_file, escape_re, md5, sane_parser_name, re, typing
 from DHParser.transform import traverse, remove_brackets, \
-    reduce_single_child, replace_by_single_child, remove_expendables, \
+    content_from_child, replace_by_child, remove_expendables, \
     remove_tokens, flatten, forbid, assert_content, remove_infix_operator
 from DHParser.versionnumber import __version__
 from typing import Callable, Dict, List, Set, Tuple
@@ -198,30 +198,30 @@ EBNF_AST_transformation_table = {
     "+":
         remove_expendables,
     "syntax":
-        [],  # otherwise '"*": replace_by_single_child' would be applied
+        [],  # otherwise '"*": replace_by_child' would be applied
     "directive, definition":
         remove_tokens('@', '='),
     "expression":
-        [replace_by_single_child, flatten, remove_tokens('|')],  # remove_infix_operator],
+        [replace_by_child, flatten, remove_tokens('|')],  # remove_infix_operator],
     "term":
-        [replace_by_single_child, flatten],  # supports both idioms:  "{ factor }+" and "factor { factor }"
+        [replace_by_child, flatten],  # supports both idioms:  "{ factor }+" and "factor { factor }"
     "factor, flowmarker, retrieveop":
-        replace_by_single_child,
+        replace_by_child,
     "group":
-        [remove_brackets, replace_by_single_child],
+        [remove_brackets, replace_by_child],
     "unordered":
         remove_brackets,
     "oneormore, repetition, option":
-        [reduce_single_child, remove_brackets,
+        [content_from_child, remove_brackets,
          forbid('repetition', 'option', 'oneormore'), assert_content(r'(?!§)')],
     "symbol, literal, regexp":
-        reduce_single_child,
+        content_from_child,
     (TOKEN_PTYPE, WHITESPACE_PTYPE):
-        reduce_single_child,
+        content_from_child,
     "list_":
         [flatten, remove_infix_operator],
     "*":
-        replace_by_single_child
+        replace_by_child
 }
 
 
@@ -438,10 +438,10 @@ class EBNFCompiler(Compiler):
             if rule.startswith('Alternative'):
                 transformations = '[replace_or_reduce]'
             elif rule.startswith('Synonym'):
-                transformations = '[reduce_single_child]'
+                transformations = '[content_from_child]'
             transtable.append('    "' + name + '": %s,' % transformations)
-        transtable.append('    ":Token, :RE": reduce_single_child,')
-        transtable += ['    "*": replace_by_single_child', '}', '']
+        transtable.append('    ":Token, :RE": content_from_child,')
+        transtable += ['    "*": replace_by_child', '}', '']
         transtable += [TRANSFORMER_FACTORY.format(NAME=self.grammar_name)]
         return '\n'.join(transtable)
 

DHParser/parser.py

@@ -1185,7 +1185,7 @@ class RE(Parser):
     >>> result.structure()
     '(:RE (:RegExp "Haus") (:Whitespace " "))'
     >>> parser(' Haus').content()
-    ' <<< Error on " Haus" | Parser did not match! Invalid source file?\\n    Most advanced: None\\n    Last match:    None; >>> '
+    ' <<< Error on " Haus" | Parser did not match! Invalid source file?\n    Most advanced: None\n    Last match:    None; >>> '
 
     EBNF-Notation:  `/ ... /~`  or  `~/ ... /`  or  `~/ ... /~`
     EBNF-Example:   `word = /\w+/~`
@@ -1437,7 +1437,7 @@ class OneOrMore(UnaryOperator):
     >>> Grammar(sentence)('Wo viel der Weisheit, da auch viel des Grämens.').content()
     'Wo viel der Weisheit, da auch viel des Grämens.'
     >>> Grammar(sentence)('.').content()  # an empty sentence also matches
-    ' <<< Error on "." | Parser did not match! Invalid source file?\\n    Most advanced: None\\n    Last match:    None; >>> '
+    ' <<< Error on "." | Parser did not match! Invalid source file?\n    Most advanced: None\n    Last match:    None; >>> '
 
     EBNF-Notation: `{ ... }+`
     EBNF-Example:  `sentence = { /\w+,?/ }+`
@@ -1480,7 +1480,7 @@ class Series(NaryOperator):
     >>> Grammar(variable_name)('variable_1').content()
     'variable_1'
     >>> Grammar(variable_name)('1_variable').content()
-    ' <<< Error on "1_variable" | Parser did not match! Invalid source file?\\n    Most advanced: None\\n    Last match:    None; >>> '
+    ' <<< Error on "1_variable" | Parser did not match! Invalid source file?\n    Most advanced: None\n    Last match:    None; >>> '
 
     EBNF-Notation: `... ...`    (sequence of parsers separated by a blank or new line)
     EBNF-Example:  `series = letter letter_or_digit`

DHParser/transform.py

@@ -36,8 +36,8 @@ __all__ = ('TransformationDict',
            'key_tag_name',
            'traverse',
            'is_named',
-           'replace_by_single_child',
-           'reduce_single_child',
+           'replace_by_child',
+           'content_from_child',
            'replace_or_reduce',
            'replace_parser',
            'collapse',
@@ -52,8 +52,7 @@ __all__ = ('TransformationDict',
            'is_one_of',
            'has_content',
            'remove_children_if',
-           'remove_children',
-           'remove_parser',
+           'remove_nodes',
            'remove_content',
            'remove_first',
            'remove_last',
@@ -70,8 +69,7 @@ __all__ = ('TransformationDict',
            'require',
            'assert_content',
            'assert_condition',
-           'assert_has_children',
-           'TRUE_CONDITION')
+           'assert_has_children')
 
 
 TransformationProc = Callable[[List[Node]], None]
@@ -79,8 +77,10 @@ TransformationDict = Dict[str, Sequence[Callable]]
 ProcessingTableType = Dict[str, Union[Sequence[Callable], TransformationDict]]
 ConditionFunc = Callable  # Callable[[List[Node]], bool]
 KeyFunc = Callable[[Node], str]
+CriteriaType = Union[int, str, Callable]
 
 
+# TODO: Add more optional type dispatch paramters, e.g. t2=None, t3=None, t4=None
 def transformation_factory(t=None):
     """Creates factory functions from transformation-functions that
     dispatch on the first parameter after the context parameter.
@@ -99,7 +99,7 @@ def transformation_factory(t=None):
     Main benefit is readability of processing tables.
 
     Usage:
-        @transformation_factory(AbtractSet[str])
+        @transformation_factory(AbstractSet[str])
         def remove_tokens(context, tokens):
             ...
       or, alternatively:
@@ -128,15 +128,18 @@ def transformation_factory(t=None):
             "annotation or provide the type information via transfomer-decorator."
         p1type = t or params[0].annotation
         f = singledispatch(f)
-        if len(params) == 1 and issubclass(p1type, Container) and not issubclass(p1type, Text) \
-                and not issubclass(p1type, ByteString):
-            def gen_special(*args):
-                c = set(args) if issubclass(p1type, AbstractSet) else \
-                    list(args) if issubclass(p1type, Sequence) else args
-                d = {params[0].name: c}
-                return partial(f, **d)
-
-            f.register(p1type.__args__[0], gen_special)
+        try:
+            if len(params) == 1 and issubclass(p1type, Container) \
+                    and not issubclass(p1type, Text) and not issubclass(p1type, ByteString):
+                def gen_special(*args):
+                    c = set(args) if issubclass(p1type, AbstractSet) else \
+                        list(args) if issubclass(p1type, Sequence) else args
+                    d = {params[0].name: c}
+                    return partial(f, **d)
+
+                f.register(p1type.__args__[0], gen_special)
+        except AttributeError:
+            pass  # Union Type does not allow subclassing, but is not needed here
 
         def gen_partial(*args, **kwargs):
             d = {p.name: arg for p, arg in zip(params, args)}
@@ -196,8 +199,8 @@ def traverse(root_node: Node,
             key_func yields node.parser.name.
 
     Example:
-        table = { "term": [replace_by_single_child, flatten],
-            "factor, flowmarker, retrieveop": replace_by_single_child }
+        table = { "term": [replace_by_child, flatten],
+            "factor, flowmarker, retrieveop": replace_by_child }
         traverse(node, table)
     """
     # Is this optimazation really needed?
@@ -262,13 +265,29 @@ def traverse(root_node: Node,
 # ------------------------------------------------
 
 
-def TRUE_CONDITION(context: List[Node]) -> bool:
-    return True
+def pick_child(context: List[Node], criteria: CriteriaType):
+    """Returns the first child that meets the criteria."""
+    if isinstance(criteria, int):
+        try:
+            return context[-1].children[criteria]
+        except IndexError:
+            return None
+    elif isinstance(criteria, str):
+        for child in context[-1].children:
+            if child.tag_name == criteria:
+                return child
+        return None
+    else:  # assume criteria has type ConditionFunc
+        for child in context[-1].children:
+            context.append(child)
+            evaluation = criteria(context)
+            context.pop()
+            if evaluation:
+                return child
+        return None
 
 
-def replace_child(node: Node):
-    assert len(node.children) == 1
-    child = node.children[0]
+def replace_by(node: Node, child: Node):
     if not child.parser.name:
         child.parser = MockParser(node.parser.name, child.parser.ptype)
         # parser names must not be overwritten, else: child.parser.name = node.parser.name
@@ -277,30 +296,56 @@ def replace_child(node: Node):
     node.result = child.result
 
 
-def reduce_child(node: Node):
-    assert len(node.children) == 1
-    node._errors.extend(node.children[0]._errors)
-    node.result = node.children[0].result
+def reduce_child(node: Node, child: Node):
+    node._errors.extend(child._errors)
+    node.result = child.result
 
 
-@transformation_factory(Callable)
-def replace_by_single_child(context: List[Node], condition: Callable=TRUE_CONDITION):
+# TODO: default value = lambda context: len(context[-1].children) == 1
+# @transformation_factory(int, str, Callable)
+# def replace_by_child(context: List[Node], criteria: CriteriaType=0):
+#     """
+#     Replace a node by the first of its immediate descendants
+#     that meets the `criteria`. The criteria can either be the
+#     index of the child (counting from zero), or the tag name or
+#     a boolean-valued function on the context of the child.
+#     If no child matching the criteria is found, the node will
+#     not be replaced.
+#     """
+#     child = pick_child(context, criteria)
+#     if child:
+#         print(child)
+#         replace_by(context[-1], child)
+
+
+# @transformation_factory(int, str, Callable)
+# def content_from_child(context: List[None], criteria: CriteriaType=0):
+#     """
+#     Reduce a node, by transferring the result of the first of its
+#     immediate descendants that meets the `criteria` to this node,
+#     but keeping this node's parser entry. The criteria can either
+#     be the index of the child (counting from zero), or the tag
+#     name or a boolean-valued function on the context of the child.
+#     If no child matching the criteria is found, the node will
+#     not be replaced.
+#     """
+#     child = pick_child(context, criteria)
+#     if child:
+#         reduce_child(context[-1], child)
+
+
+
+def replace_by_child(context: List[Node]):
     """
     Remove single branch node, replacing it by its immediate descendant
-    if and only if the condision on the descendant is true.
-    (In case the descendant's name is empty (i.e. anonymous) the
-    name of this node's parser is kept.)
+    if and only if the condition on the descendant is true.
     """
     node = context[-1]
     if len(node.children) == 1:
-        context.append(node.children[0])
-        if condition(context):
-            replace_child(node)
-        context.pop()
+        replace_by(node, node.children[0])
 
 
-@transformation_factory(Callable)
-def reduce_single_child(context: List[Node], condition: Callable=TRUE_CONDITION):
+def content_from_child(context: List[Node]):
     """
     Reduce a single branch node, by transferring the result of its
     immediate descendant to this node, but keeping this node's parser entry.
@@ -309,10 +354,7 @@ def reduce_single_child(context: List[Node], condition: Callable=TRUE_CONDITION)
     """
     node = context[-1]
     if len(node.children) == 1:
-        context.append(node.children[0])
-        if condition(context):
-            reduce_child(node)
-        context.pop()
+        reduce_child(node, node.children[0])
 
 
 def is_named(context: List[Node]) -> bool:
@@ -333,7 +375,7 @@ def replace_or_reduce(context: List[Node], condition: Callable=is_named):
     if len(node.children) == 1:
         context.append(node.children[0])
         if condition(context):
-            replace_child(node)
+            replace_by(node)
         else:
             reduce_child(node)
         context.pop()
@@ -497,27 +539,27 @@ def remove_children_if(context: List[Node], condition: Callable):  # , section:
         node.result = tuple(c for c in node.children if not condition(context + [c]))
 
 
-@transformation_factory(Callable)
-def remove_children(context: List[Node],
-                    condition: Callable = TRUE_CONDITION,
-                    section: slice = slice(None)):
-    """Removes all nodes from a slice of the result field if the function
-    `condition(child_node)` evaluates to `True`."""
-    node = context[-1]
-    if node.children:
-        c = node.children
-        N = len(c)
-        rng = range(*section.indices(N))
-        node.result = tuple(c[i] for i in range(N)
-                            if i not in rng or not condition(context + [c[i]]))
-        # selection = []
-        # for i in range(N):
-        #     context.append(c[i])
-        #     if not i in rng or not condition(context):
-        #         selection.append(c[i])
-        #     context.pop()
-        # if len(selection) != c:
-        #     node.result = tuple(selection)
+# @transformation_factory(Callable)
+# def remove_children(context: List[Node],
+#                     condition: Callable = TRUE_CONDITION,
+#                     section: slice = slice(None)):
+#     """Removes all nodes from a slice of the result field if the function
+#     `condition(child_node)` evaluates to `True`."""
+#     node = context[-1]
+#     if node.children:
+#         c = node.children
+#         N = len(c)
+#         rng = range(*section.indices(N))
+#         node.result = tuple(c[i] for i in range(N)
+#                             if i not in rng or not condition(context + [c[i]]))
+#         # selection = []
+#         # for i in range(N):
+#         #     context.append(c[i])
+#         #     if not i in rng or not condition(context):
+#         #         selection.append(c[i])
+#         #     context.pop()
+#         # if len(selection) != c:
+#         #     node.result = tuple(selection)
 
 
 remove_whitespace = remove_children_if(is_whitespace)  # partial(remove_children_if, condition=is_whitespace)
@@ -539,7 +581,7 @@ def remove_tokens(context: List[Node], tokens: AbstractSet[str] = frozenset()):
 
 
 @transformation_factory
-def remove_parser(context: List[Node], tag_names: AbstractSet[str]):
+def remove_nodes(context: List[Node], tag_names: AbstractSet[str]):
     """Removes children by tag name."""
     remove_children_if(context, partial(is_one_of, tag_name_set=tag_names))
 

Introduction.md

@@ -366,22 +366,22 @@ scroll down to the AST section, you'll see something like this:
     Lyrik_AST_transformation_table = {
         # AST Transformations for the Lyrik-grammar
         "+": remove_empty,
-        "bibliographisches": [remove_parser('NZ'), remove_tokens],
+        "bibliographisches": [remove_nodes('NZ'), remove_tokens],
         "autor, werk, untertitel, ort": [],
-        "jahr": [reduce_single_child],
+        "jahr": [content_from_child],
         "wortfolge": [flatten(is_one_of('WORT'), recursive=False), remove_last(is_whitespace), collapse],
         "namenfolge": [flatten(is_one_of('NAME'), recursive=False), remove_last(is_whitespace), collapse],
-        "verknüpfung": [remove_tokens('<', '>'), reduce_single_child],
-        "ziel": reduce_single_child,
-        "gedicht, strophe, text": [flatten, remove_parser('LEERZEILE'), remove_parser('NZ')],
-        "titel, serie": [flatten, remove_parser('LEERZEILE'), remove_parser('NZ'), collapse],
+        "verknüpfung": [remove_tokens('<', '>'), content_from_child],
+        "ziel": content_from_child,
+        "gedicht, strophe, text": [flatten, remove_nodes('LEERZEILE'), remove_nodes('NZ')],
+        "titel, serie": [flatten, remove_nodes('LEERZEILE'), remove_nodes('NZ'), collapse],
         "vers": collapse,
         "zeile": [],
-        "ZEICHENFOLGE, NZ, JAHRESZAHL": reduce_single_child,
+        "ZEICHENFOLGE, NZ, JAHRESZAHL": content_from_child,
         "WORT, NAME, LEERZEILE, ENDE": [],
         ":Whitespace": replace_content(lambda node : " "),
-        ":Token, :RE": reduce_single_child,
-        "*": replace_by_single_child
+        ":Token, :RE": content_from_child,
+        "*": replace_by_child
     }
 
 As you can see, AST-transformations a specified declaratively (with the

examples/BibTeX/BibTeXCompiler.py

@@ -25,9 +25,9 @@ from DHParser import logging, is_filename, load_if_file, \
     last_value, counterpart, accumulate, PreprocessorFunc, \
     Node, TransformationFunc, TransformationDict, TRUE_CONDITION, \
     traverse, remove_children_if, merge_children, is_anonymous, \
-    reduce_single_child, replace_by_single_child, replace_or_reduce, remove_whitespace, \
+    content_from_child, replace_by_child, replace_or_reduce, remove_whitespace, \
     remove_expendables, remove_empty, remove_tokens, flatten, is_whitespace, \
-    is_empty, is_expendable, collapse, replace_content, remove_parser, remove_content, remove_brackets, replace_parser, \
+    is_empty, is_expendable, collapse, replace_content, remove_nodes, remove_content, remove_brackets, replace_parser, \
     keep_children, is_one_of, has_content, apply_if, remove_first, remove_last, \
     WHITESPACE_PTYPE, TOKEN_PTYPE
 
@@ -159,8 +159,8 @@ BibTeX_AST_transformation_table = {
     "content": [replace_or_reduce],
     "plain_content": [],
     "text": [],
-    ":Token, :RE": reduce_single_child,
-    "*": replace_by_single_child
+    ":Token, :RE": content_from_child,
+    "*": replace_by_child
 }
 
 

examples/EBNF/EBNFCompiler.py

@@ -22,10 +22,10 @@ from DHParser import logging, is_filename, load_if_file, \
     last_value, counterpart, accumulate, PreprocessorFunc, \
     Node, TransformationFunc, TransformationDict, TRUE_CONDITION, \
     traverse, remove_children_if, merge_children, is_anonymous, \
-    reduce_single_child, replace_by_single_child, replace_or_reduce, remove_whitespace, \
+    content_from_child, replace_by_child, replace_or_reduce, remove_whitespace, \
     remove_expendables, remove_empty, remove_tokens, flatten, is_whitespace, \
     is_empty, is_expendable, collapse, replace_content, WHITESPACE_PTYPE, TOKEN_PTYPE, \
-    remove_parser, remove_content, remove_brackets, replace_parser, \
+    remove_nodes, remove_content, remove_brackets, replace_parser, \
     keep_children, is_one_of, has_content, apply_if, remove_first, remove_last
 
 
@@ -156,8 +156,8 @@ EBNF_AST_transformation_table = {
     "regexp": [],
     "list_": [],
     "EOF": [],
-    ":Token, :RE": reduce_single_child,
-    "*": replace_by_single_child
+    ":Token, :RE": content_from_child,
+    "*": replace_by_child
 }
 
 

examples/LaTeX/LaTeXCompiler.py

@@ -21,9 +21,9 @@ from DHParser import logging, is_filename, Grammar, Compiler, Lookbehind, Altern
     ZeroOrMore, Forward, NegativeLookahead, mixin_comment, compile_source, \
     PreprocessorFunc, TransformationDict, \
     Node, TransformationFunc, traverse, remove_children_if, is_anonymous, \
-    reduce_single_child, replace_by_single_child, remove_whitespace, \
+    content_from_child, replace_by_child, remove_whitespace, \
     flatten, is_empty, collapse, replace_content, remove_brackets, is_one_of, remove_first, \
-    remove_tokens, remove_parser, TOKEN_PTYPE
+    remove_tokens, remove_nodes, TOKEN_PTYPE
 
 
 #######################################################################
@@ -230,7 +230,7 @@ class LaTeXGrammar(Grammar):
     paragraph = Forward()
     tabular_config = Forward()
     text_element = Forward()
-    source_hash__ = "1ded00ed838b03fcffcc6cd4333d4ae0"
+    source_hash__ = "a078d3d46ee55a7543f37c62b3fb24a7"
     parser_initialization__ = "upon instantiation"
     COMMENT__ = r'%.*'
     WHITESPACE__ = r'[ \t]*(?:\n(?![ \t]*\n)[ \t]*)?'
@@ -389,52 +389,52 @@ LaTeX_AST_transformation_table = {
     "latexdoc": [],
     "preamble": [],
     "document": [flatten_structure],
-    "frontpages": reduce_single_child,
+    "frontpages": content_from_child,
     "Chapters, Sections, SubSections, SubSubSections, Paragraphs, SubParagraphs": [],
     "Chapter, Section, SubSection, SubSubSection, Paragraph, SubParagraph": [],
-    "heading": reduce_single_child,
+    "heading": content_from_child,
     "Bibliography": [],
     "Index": [],
-    "block_environment": replace_by_single_child,
-    "known_environment": replace_by_single_child,
+    "block_environment": replace_by_child,
+    "known_environment": replace_by_child,
     "generic_block": [],
-    "begin_generic_block, end_generic_block": [remove_parser('NEW_LINE'), replace_by_single_child],
+    "begin_generic_block, end_generic_block": [remove_nodes('NEW_LINE'), replace_by_child],
     "itemize, enumerate": [remove_brackets, flatten],
     "item": [],
     "figure": [],
-    "quotation": [reduce_single_child, remove_brackets],
+    "quotation": [content_from_child, remove_brackets],
     "verbatim": [],
     "tabular": [],
-    "tabular_config, block_of_paragraphs": [remove_brackets, reduce_single_child],
+    "tabular_config, block_of_paragraphs": [remove_brackets, content_from_child],
     "tabular_row": [flatten, remove_tokens('&', '\\')],
     "tabular_cell": [flatten, remove_whitespace],
     "multicolumn": [remove_tokens('{', '}')],
-    "hline": [remove_whitespace, reduce_single_child],
+    "hline": [remove_whitespace, content_from_child],
     "sequence": [flatten],
     "paragraph": [flatten],
-    "text_element": replace_by_single_child,
-    "line_element": replace_by_single_child,
-    "inline_environment": replace_by_single_child,
-    "known_inline_env": replace_by_single_child,
+    "text_element": replace_by_child,
+    "line_element": replace_by_child,
+    "inline_environment": replace_by_child,
+    "known_inline_env": replace_by_child,
     "generic_inline_env": [],
-    "begin_inline_env, end_inline_env": [replace_by_single_child],
-    "begin_environment, end_environment": [remove_brackets, reduce_single_child],
-    "inline_math": [remove_brackets, reduce_single_child],
-    "command": replace_by_single_child,
-    "known_command": replace_by_single_child,
+    "begin_inline_env, end_inline_env": [replace_by_child],
+    "begin_environment, end_environment": [remove_brackets, content_from_child],
+    "inline_math": [remove_brackets, content_from_child],
+    "command": replace_by_child,