# License along with Hooke. If not, see
# <http://www.gnu.org/licenses/>.
-"""The ``command_stack`` module provides tools for managing stacks of
-:class:`~hooke.engine.CommandMessage`\s and applying those stacks to
-:class:`~hooke.curve.Curve`\s.
+"""The ``command_stack`` module provides tools for managing and
+executing stacks of :class:`~hooke.engine.CommandMessage`\s.
"""
-from .command import Command, Argument, Failure
+import os
+import os.path
+
+import yaml
+
from .engine import CommandMessage
-from .playlist import NoteIndexList
+
+
+class CommandStack (list):
+ """Store a stack of commands.
+
+ Examples
+ --------
+ >>> c = CommandStack([CommandMessage('CommandA', {'param':'A'})])
+ >>> c.append(CommandMessage('CommandB', {'param':'B'}))
+ >>> c.append(CommandMessage('CommandA', {'param':'C'}))
+ >>> c.append(CommandMessage('CommandB', {'param':'D'}))
+
+ Implement a dummy :meth:`execute_command` for testing.
+
+ >>> def execute_cmd(hooke, command_message):
+ ... cm = command_message
+ ... print 'EXECUTE', cm.command, cm.arguments
+ >>> c.execute_command = execute_cmd
+
+ >>> c.execute(hooke=None) # doctest: +ELLIPSIS
+ EXECUTE CommandA {'param': 'A'}
+ EXECUTE CommandB {'param': 'B'}
+ EXECUTE CommandA {'param': 'C'}
+ EXECUTE CommandB {'param': 'D'}
+
+ :meth:`filter` allows you to select which commands get executed.
+ If, for example, you are applying a set of commands to the current
+ :class:`~hooke.curve.Curve`, you may only want to execute
+ instances of :class:`~hooke.plugin.curve.CurveCommand`. Here we
+ only execute commands named `CommandB`.
+
+ >>> def filter(hooke, command_message):
+ ... return command_message.command == 'CommandB'
+ >>> c.filter = filter
+
+ Apply the stack to the current curve.
+
+ >>> c.execute(hooke=None) # doctest: +ELLIPSIS
+ EXECUTE CommandB {'param': 'B'}
+ EXECUTE CommandB {'param': 'D'}
+
+ Execute a new command and add it to the stack.
+
+ >>> cm = CommandMessage('CommandC', {'param':'E'})
+ >>> c.execute_command(hooke=None, command_message=cm)
+ EXECUTE CommandC {'param': 'E'}
+ >>> c.append(cm)
+ >>> print [repr(cm) for cm in c] # doctest: +NORMALIZE_WHITESPACE
+ ['<CommandMessage CommandA {param: A}>',
+ '<CommandMessage CommandB {param: B}>',
+ '<CommandMessage CommandA {param: C}>',
+ '<CommandMessage CommandB {param: D}>',
+ '<CommandMessage CommandC {param: E}>']
+
+ There is also a convenience function for clearing the stack.
+
+ >>> c.clear()
+ >>> print [repr(cm) for cm in c]
+ []
+ """
+ def execute(self, hooke):
+ """Execute a stack of commands.
+
+ See Also
+ --------
+ _execute, filter
+ """
+ for command_message in self:
+ if self.filter(hooke, command_message) == True:
+ self.execute_command(
+ hooke=hooke, command_message=command_message)
+
+ def filter(self, hooke, command_message):
+ """Return `True` to execute `command_message`, `False` otherwise.
+
+ The default implementation always returns `True`.
+ """
+ return True
+
+ def execute_command(self, hooke, command_message):
+ hooke.run_command(command=command_message.command,
+ arguments=command_message.arguments)
+
+ def clear(self):
+ while len(self) > 0:
+ self.pop()
+
+
+class FileCommandStack (CommandStack):
+ """A file-backed :class:`CommandStack`.
+ """
+ version = '0.1'
+
+ def __init__(self, *args, **kwargs):
+ super(FileCommandStack, self).__init__(*args, **kwargs)
+ self.name = None
+ self.path = None
+
+ def set_path(self, path):
+ """Set the path (and possibly the name) of the command stack.
+
+ Examples
+ --------
+ >>> c = FileCommandStack([CommandMessage('CommandA', {'param':'A'})])
+
+ :attr:`name` is set only if it starts out equal to `None`.
+ >>> c.name == None
+ True
+ >>> c.set_path(os.path.join('path', 'to', 'my', 'command', 'stack'))
+ >>> c.path
+ 'path/to/my/command/stack'
+ >>> c.name
+ 'stack'
+ >>> c.set_path(os.path.join('another', 'path'))
+ >>> c.path
+ 'another/path'
+ >>> c.name
+ 'stack'
+ """
+ if path != None:
+ self.path = path
+ if self.name == None:
+ self.name = os.path.basename(path)
+
+ def save(self, path=None, makedirs=True):
+ """Saves the command stack to `path`.
+ """
+ self.set_path(path)
+ dirname = os.path.dirname(self.path)
+ if makedirs == True and not os.path.isdir(dirname):
+ os.makedirs(dirname)
+ with open(self.path, 'w') as f:
+ f.write(self.flatten())
+
+ def load(self, path=None):
+ """Load a command stack from `path`.
+ """
+ self.set_path(path)
+ with open(self.path, 'r') as f:
+ text = f.read()
+ self.from_string(text)
+
+ def flatten(self):
+ """Create a string representation of the command stack.
+
+ A playlist is a YAML document with the following syntax::
+
+ - arguments: {param: A}
+ command: CommandA
+ - arguments: {param: B, ...}
+ command: CommandB
+ ...
+
+ Examples
+ --------
+ >>> c = FileCommandStack([CommandMessage('CommandA', {'param':'A'})])
+ >>> c.append(CommandMessage('CommandB', {'param':'B'}))
+ >>> c.append(CommandMessage('CommandA', {'param':'C'}))
+ >>> c.append(CommandMessage('CommandB', {'param':'D'}))
+ >>> print c.flatten()
+ - arguments: {param: A}
+ command: CommandA
+ - arguments: {param: B}
+ command: CommandB
+ - arguments: {param: C}
+ command: CommandA
+ - arguments: {param: D}
+ command: CommandB
+ <BLANKLINE>
+ """
+ return yaml.dump([{'command':cm.command,'arguments':cm.arguments}
+ for cm in self])
+
+ def from_string(self, string):
+ """Load a playlist from a string.
+
+ .. warning:: This is *not safe* with untrusted input.
+
+ Examples
+ --------
+
+ >>> string = '''- arguments: {param: A}
+ ... command: CommandA
+ ... - arguments: {param: B}
+ ... command: CommandB
+ ... - arguments: {param: C}
+ ... command: CommandA
+ ... - arguments: {param: D}
+ ... command: CommandB
+ ... '''
+ >>> c = FileCommandStack()
+ >>> c.from_string(string)
+ >>> print [repr(cm) for cm in c] # doctest: +NORMALIZE_WHITESPACE
+ ['<CommandMessage CommandA {param: A}>',
+ '<CommandMessage CommandB {param: B}>',
+ '<CommandMessage CommandA {param: C}>',
+ '<CommandMessage CommandB {param: D}>']
+ """
+ for x in yaml.load(string):
+ self.append(CommandMessage(command=x['command'],
+ arguments=x['arguments']))
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