text: #     Copyright 2021, Kay Hayen, mailto:kay.hayen@gmail.com
  #
  #     Part of "Nuitka", an optimizing Python compiler that is compatible and
  #     integrates with CPython, but also works on its own.
  #
  #     Licensed under the Apache License, Version 2.0 (the "License");
  #     you may not use this file except in compliance with the License.
  #     You may obtain a copy of the License at
  #
  #        http://www.apache.org/licenses/LICENSE-2.0
  #
  #     Unless required by applicable law or agreed to in writing, software
  #     distributed under the License is distributed on an "AS IS" BASIS,
  #     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #     See the License for the specific language governing permissions and
  #     limitations under the License.
  #
  """ Reformulation of sequence creations.
  
  Sequences might be directly translated to constants, or they might become
  nodes that build tuples, lists, or sets.
  
  For Python3.5, unpacking can happen while creating sequences, these are
  being re-formulated to an internal function.
  
  Consult the developer manual for information. TODO: Add ability to sync
  source code comments with developer manual sections.
  
  """
  
  from nuitka.nodes.AssignNodes import (
      StatementAssignmentVariable,
      StatementReleaseVariable,
  )
  from nuitka.nodes.BuiltinIteratorNodes import ExpressionBuiltinIter1
  from nuitka.nodes.BuiltinNextNodes import ExpressionBuiltinNext1
  from nuitka.nodes.BuiltinTypeNodes import ExpressionBuiltinTuple
  from nuitka.nodes.ConstantRefNodes import makeConstantRefNode
  from nuitka.nodes.ContainerMakingNodes import (
      makeExpressionMakeListOrConstant,
      makeExpressionMakeSetLiteralOrConstant,
      makeExpressionMakeTuple,
      makeExpressionMakeTupleOrConstant,
  )
  from nuitka.nodes.ContainerOperationNodes import (
      ExpressionListOperationExtend,
      ExpressionListOperationExtendForUnpack,
      ExpressionSetOperationUpdate,
  )
  from nuitka.nodes.FunctionNodes import (
      ExpressionFunctionCall,
      ExpressionFunctionCreation,
      ExpressionFunctionRef,
  )
  from nuitka.nodes.LoopNodes import StatementLoop, StatementLoopBreak
  from nuitka.nodes.ReturnNodes import StatementReturn
  from nuitka.nodes.StatementNodes import StatementExpressionOnly
  from nuitka.nodes.VariableRefNodes import (
      ExpressionTempVariableRef,
      ExpressionVariableRef,
  )
  from nuitka.PythonVersions import python_version
  from nuitka.specs.ParameterSpecs import ParameterSpec
  
  from . import SyntaxErrors
  from .InternalModule import (
      internal_source_ref,
      makeInternalHelperFunctionBody,
      once_decorator,
  )
  from .ReformulationTryExceptStatements import makeTryExceptSingleHandlerNode
  from .ReformulationTryFinallyStatements import makeTryFinallyStatement
  from .TreeHelpers import (
      buildNode,
      buildNodeList,
      getKind,
      makeStatementsSequenceFromStatement,
      makeStatementsSequenceFromStatements,
  )
  
  
  def _raiseStarredSyntaxError(element, source_ref):
      SyntaxErrors.raiseSyntaxError(
          "can use starred expression only as assignment target",
          source_ref.atColumnNumber(element.col_offset),
      )
  
  
  def buildTupleCreationNode(provider, node, source_ref):
      if python_version >= 0x300:
          for element in node.elts:
              if getKind(element) == "Starred":
                  if python_version < 0x350:
                      _raiseStarredSyntaxError(element, source_ref)
                  else:
                      return buildTupleUnpacking(
                          provider=provider, elements=node.elts, source_ref=source_ref
                      )
  
      return makeExpressionMakeTupleOrConstant(
          elements=buildNodeList(provider, node.elts, source_ref),
          user_provided=True,
          source_ref=source_ref,
      )
  
  
  def buildListCreationNode(provider, node, source_ref):
      if python_version >= 0x300:
          for element in node.elts:
              if getKind(element) == "Starred":
                  if python_version < 0x350:
                      _raiseStarredSyntaxError(element, source_ref)
                  else:
                      return buildListUnpacking(
                          provider=provider, elements=node.elts, source_ref=source_ref
                      )
  
      return makeExpressionMakeListOrConstant(
          elements=buildNodeList(provider, node.elts, source_ref),
          user_provided=True,
          source_ref=source_ref,
      )
  
  
  def buildSetCreationNode(provider, node, source_ref):
      if python_version >= 0x300:
          for element in node.elts:
              if getKind(element) == "Starred":
                  if python_version < 0x350:
                      _raiseStarredSyntaxError(element, source_ref)
                  else:
                      return _buildSetUnpacking(
                          provider=provider, elements=node.elts, source_ref=source_ref
                      )
  
      return makeExpressionMakeSetLiteralOrConstant(
          elements=buildNodeList(provider, node.elts, source_ref),
          user_provided=True,
          source_ref=source_ref,
      )
  
  
  @once_decorator
  def getListUnpackingHelper():
      helper_name = "_unpack_list"
  
      result = makeInternalHelperFunctionBody(
          name=helper_name,
          parameters=ParameterSpec(
              ps_name=helper_name,
              ps_normal_args=(),
              ps_list_star_arg="args",
              ps_dict_star_arg=None,
              ps_default_count=0,
              ps_kw_only_args=(),
              ps_pos_only_args=(),
          ),
      )
  
      temp_scope = None
  
      tmp_result_variable = result.allocateTempVariable(temp_scope, "list")
      tmp_iter_variable = result.allocateTempVariable(temp_scope, "iter")
      tmp_item_variable = result.allocateTempVariable(temp_scope, "keys")
  
      if python_version < 0x390:
          list_operation_extend = ExpressionListOperationExtend
      else:
          list_operation_extend = ExpressionListOperationExtendForUnpack
  
      loop_body = makeStatementsSequenceFromStatements(
          makeTryExceptSingleHandlerNode(
              tried=StatementAssignmentVariable(
                  variable=tmp_item_variable,
                  source=ExpressionBuiltinNext1(
                      value=ExpressionTempVariableRef(
                          variable=tmp_iter_variable, source_ref=internal_source_ref
                      ),
                      source_ref=internal_source_ref,
                  ),
                  source_ref=internal_source_ref,
              ),
              exception_name="StopIteration",
              handler_body=StatementLoopBreak(source_ref=internal_source_ref),
              source_ref=internal_source_ref,
          ),
          StatementExpressionOnly(
              expression=list_operation_extend(
                  list_arg=ExpressionTempVariableRef(
                      variable=tmp_result_variable, source_ref=internal_source_ref
                  ),
                  value=ExpressionTempVariableRef(
                      variable=tmp_item_variable, source_ref=internal_source_ref
                  ),
                  source_ref=internal_source_ref,
              ),
              source_ref=internal_source_ref,
          ),
      )
  
      args_variable = result.getVariableForAssignment(variable_name="args")
  
      final = (
          StatementReleaseVariable(
              variable=tmp_result_variable, source_ref=internal_source_ref
          ),
          StatementReleaseVariable(
              variable=tmp_iter_variable, source_ref=internal_source_ref
          ),
          StatementReleaseVariable(
              variable=tmp_item_variable, source_ref=internal_source_ref
          ),
      )
  
      tried = makeStatementsSequenceFromStatements(
          StatementAssignmentVariable(
              variable=tmp_iter_variable,
              source=ExpressionBuiltinIter1(
                  value=ExpressionVariableRef(
                      variable=args_variable, source_ref=internal_source_ref
                  ),
                  source_ref=internal_source_ref,
              ),
              source_ref=internal_source_ref,
          ),
          StatementAssignmentVariable(
              variable=tmp_result_variable,
              source=makeConstantRefNode(constant=[], source_ref=internal_source_ref),
              source_ref=internal_source_ref,
          ),
          StatementLoop(loop_body=loop_body, source_ref=internal_source_ref),
          StatementReturn(
              expression=ExpressionTempVariableRef(
                  variable=tmp_result_variable, source_ref=internal_source_ref
              ),
              source_ref=internal_source_ref,
          ),
      )
  
      result.setChild(
          "body",
          makeStatementsSequenceFromStatement(
              makeTryFinallyStatement(
                  provider=result,
                  tried=tried,
                  final=final,
                  source_ref=internal_source_ref,
              )
          ),
      )
  
      return result
  
  
  @once_decorator
  def getSetUnpackingHelper():
      helper_name = "_unpack_set"
  
      result = makeInternalHelperFunctionBody(
          name=helper_name,
          parameters=ParameterSpec(
              ps_name=helper_name,
              ps_normal_args=(),
              ps_list_star_arg="args",
              ps_dict_star_arg=None,
              ps_default_count=0,
              ps_kw_only_args=(),
              ps_pos_only_args=(),
          ),
      )
  
      temp_scope = None
  
      tmp_result_variable = result.allocateTempVariable(temp_scope, "set")
      tmp_iter_variable = result.allocateTempVariable(temp_scope, "iter")
      tmp_item_variable = result.allocateTempVariable(temp_scope, "keys")
  
      loop_body = makeStatementsSequenceFromStatements(
          makeTryExceptSingleHandlerNode(
              tried=StatementAssignmentVariable(
                  variable=tmp_item_variable,
                  source=ExpressionBuiltinNext1(
                      value=ExpressionTempVariableRef(
                          variable=tmp_iter_variable, source_ref=internal_source_ref
                      ),
                      source_ref=internal_source_ref,
                  ),
                  source_ref=internal_source_ref,
              ),
              exception_name="StopIteration",
              handler_body=StatementLoopBreak(source_ref=internal_source_ref),
              source_ref=internal_source_ref,
          ),
          StatementExpressionOnly(
              expression=ExpressionSetOperationUpdate(
                  set_arg=ExpressionTempVariableRef(
                      variable=tmp_result_variable, source_ref=internal_source_ref
                  ),
                  value=ExpressionTempVariableRef(
                      variable=tmp_item_variable, source_ref=internal_source_ref
                  ),
                  source_ref=internal_source_ref,
              ),
              source_ref=internal_source_ref,
          ),
      )
  
      args_variable = result.getVariableForAssignment(variable_name="args")
  
      final = (
          StatementReleaseVariable(
              variable=tmp_result_variable, source_ref=internal_source_ref
          ),
          StatementReleaseVariable(
              variable=tmp_iter_variable, source_ref=internal_source_ref
          ),
          StatementReleaseVariable(
              variable=tmp_item_variable, source_ref=internal_source_ref
          ),
      )
  
      tried = makeStatementsSequenceFromStatements(
          StatementAssignmentVariable(
              variable=tmp_iter_variable,
              source=ExpressionBuiltinIter1(
                  value=ExpressionVariableRef(
                      variable=args_variable, source_ref=internal_source_ref
                  ),
                  source_ref=internal_source_ref,
              ),
              source_ref=internal_source_ref,
          ),
          StatementAssignmentVariable(
              variable=tmp_result_variable,
              source=makeConstantRefNode(constant=set(), source_ref=internal_source_ref),
              source_ref=internal_source_ref,
          ),
          StatementLoop(loop_body=loop_body, source_ref=internal_source_ref),
          StatementReturn(
              expression=ExpressionTempVariableRef(
                  variable=tmp_result_variable, source_ref=internal_source_ref
              ),
              source_ref=internal_source_ref,
          ),
      )
  
      result.setChild(
          "body",
          makeStatementsSequenceFromStatement(
              makeTryFinallyStatement(
                  provider=result,
                  tried=tried,
                  final=final,
                  source_ref=internal_source_ref,
              )
          ),
      )
  
      return result
  
  
  def buildListUnpacking(provider, elements, source_ref):
      helper_args = []
  
      for element in elements:
  
          # We could be a lot cleverer about the tuples for non-starred
          # arguments, but lets get this to work first. And then rely on
          # future optimization to inline the list unpacking helper in a
          # way that has the same effect.
          if getKind(element) == "Starred":
              helper_args.append(buildNode(provider, element.value, source_ref))
          else:
              helper_args.append(
                  makeExpressionMakeTupleOrConstant(
                      elements=(buildNode(provider, element, source_ref),),
                      user_provided=True,
                      source_ref=source_ref,
                  )
              )
  
      result = ExpressionFunctionCall(
          function=ExpressionFunctionCreation(
              function_ref=ExpressionFunctionRef(
                  function_body=getListUnpackingHelper(), source_ref=source_ref
              ),
              defaults=(),
              kw_defaults=None,
              annotations=None,
              source_ref=source_ref,
          ),
          values=(makeExpressionMakeTuple(helper_args, source_ref),),
          source_ref=source_ref,
      )
  
      result.setCompatibleSourceReference(helper_args[-1].getCompatibleSourceReference())
  
      return result
  
  
  def buildTupleUnpacking(provider, elements, source_ref):
      return ExpressionBuiltinTuple(
          value=buildListUnpacking(provider, elements, source_ref), source_ref=source_ref
      )
  
  
  def _buildSetUnpacking(provider, elements, source_ref):
      helper_args = []
  
      for element in elements:
  
          # We could be a lot cleverer about the tuples for non-starred
          # arguments, but lets get this to work first. And then rely on
          # future optimization to inline the list unpacking helper in a
          # way that has the same effect.
          if getKind(element) == "Starred":
              helper_args.append(buildNode(provider, element.value, source_ref))
          else:
              helper_args.append(
                  makeExpressionMakeTupleOrConstant(
                      elements=(buildNode(provider, element, source_ref),),
                      user_provided=True,
                      source_ref=source_ref,
                  )
              )
  
      result = ExpressionFunctionCall(
          function=ExpressionFunctionCreation(
              function_ref=ExpressionFunctionRef(
                  function_body=getSetUnpackingHelper(), source_ref=source_ref
              ),
              defaults=(),
              kw_defaults=None,
              annotations=None,
              source_ref=source_ref,
          ),
          values=(makeExpressionMakeTuple(helper_args, source_ref),),
          source_ref=source_ref,
      )
  
      result.setCompatibleSourceReference(helper_args[-1].getCompatibleSourceReference())
  
      return result
  