Edit File: btm_matcher.cpython-37.pyc
B � f� � @ sl d Z dZddlZddlZddlmZ ddlmZ ddlm Z G dd � d e �Z G d d � d e �Z i a d d � ZdS )a� A bottom-up tree matching algorithm implementation meant to speed up 2to3's matching process. After the tree patterns are reduced to their rarest linear path, a linear Aho-Corasick automaton is created. The linear automaton traverses the linear paths from the leaves to the root of the AST and returns a set of nodes for further matching. This reduces significantly the number of candidate nodes.z+George Boutsioukis <gboutsioukis@gmail.com>� N)� defaultdict� )�pytree)� reduce_treec @ s e Zd ZdZe�� Zdd� ZdS )�BMNodez?Class for a node of the Aho-Corasick automaton used in matchingc C s" i | _ g | _ttj�| _d| _d S )N� )�transition_table�fixers�nextr �count�id�content)�self� r �8/opt/alt/python37/lib64/python3.7/lib2to3/btm_matcher.py�__init__ s zBMNode.__init__N)�__name__� __module__� __qualname__�__doc__� itertoolsr r r r r r r s r c @ s8 e Zd ZdZdd� Zdd� Zdd� Zdd � Zd d � Zd S ) � BottomMatcherzgThe main matcher class. After instantiating the patterns should be added using the add_fixer methodc C s0 t � | _t� | _| jg| _g | _t�d�| _d S )NZRefactoringTool) �set�matchr �rootZnodesr �loggingZ getLoggerZlogger)r r r r r s zBottomMatcher.__init__c C sL | j �|� t|j�}|�� }| j|| jd�}x|D ]}|j �|� q4W dS )z�Reduces a fixer's pattern tree to a linear path and adds it to the matcher(a common Aho-Corasick automaton). The fixer is appended on the matching states and called when they are reached)�startN)r �appendr Z pattern_treeZget_linear_subpattern�addr )r �fixerZtreeZlinear� match_nodesZ match_noder r r � add_fixer% s zBottomMatcher.add_fixerc C s� |s |gS t |d t�rhg }xF|d D ]:}| j||d�}x&|D ] }|�| �|dd� |�� q>W q&W |S |d |jkr�t� }||j|d < n|j|d }|dd� r�| j|dd� |d�}n|g}|S dS )z5Recursively adds a linear pattern to the AC automatonr )r r N)� isinstance�tupler �extendr r )r �patternr r Z alternativeZ end_nodes�endZ next_noder r r r 1 s" " zBottomMatcher.addc C s | j }tt�}x�|D ]�}|}x�|r�d|_x,|jD ]"}t|tj�r0|jdkr0d|_P q0W |j dkrh|j}n|j }||j kr�|j | }xj|j D ]}|| � |� q�W nL| j }|j dk r�|j jr�P ||j kr�|j | }x |j D ]}|| � |� q�W |j }q W qW |S )au The main interface with the bottom matcher. The tree is traversed from the bottom using the constructed automaton. Nodes are only checked once as the tree is retraversed. When the automaton fails, we give it one more shot(in case the above tree matches as a whole with the rejected leaf), then we break for the next leaf. There is the special case of multiple arguments(see code comments) where we recheck the nodes Args: The leaves of the AST tree to be matched Returns: A dictionary of node matches with fixers as the keys T�;Fr N)r r �listZ was_checkedZchildrenr" r ZLeaf�value�typer r r �parent) r ZleavesZcurrent_ac_nodeZresultsZleafZcurrent_ast_nodeZchildZ node_tokenr r r r �runS s6 zBottomMatcher.runc s* t d� � fdd�� � | j� t d� dS )z<Prints a graphviz diagram of the BM automaton(for debugging)z digraph g{c s^ xX| j �� D ]J}| j | }td| j|jt|�t|j�f � |dkrNt|j� � |� q W d S )Nz%d -> %d [label=%s] //%sr )r �keys�printr � type_repr�strr r )ZnodeZ subnode_keyZsubnode)� print_noder r r1 � s z*BottomMatcher.print_ac.<locals>.print_node�}N)r. r )r r )r1 r �print_ac� s zBottomMatcher.print_acN) r r r r r r! r r, r3 r r r r r s "8r c C sH t s<ddlm} x*|j�� D ] \}}t|�tkr |t |< q W t �| | �S )Nr )�python_symbols)� _type_reprsZpygramr4 �__dict__�itemsr* �int� setdefault)Ztype_numr4 �name�valr r r r/ � s r/ )r � __author__r r � collectionsr r r Z btm_utilsr �objectr r r5 r/ r r r r �<module> s
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