Move Python code to its own directory.

bin/python/jsonpath_rw/parser.py

@@ -0,0 +1,187 @@
+from __future__ import print_function, absolute_import, division, generators, nested_scopes
+import sys
+import os.path
+import logging
+
+import ply.yacc
+
+from jsonpath_rw.jsonpath import *
+from jsonpath_rw.lexer import JsonPathLexer
+
+logger = logging.getLogger(__name__)
+
+def parse(string):
+    return JsonPathParser().parse(string)
+
+class JsonPathParser(object):
+    '''
+    An LALR-parser for JsonPath
+    '''
+    
+    tokens = JsonPathLexer.tokens
+
+    def __init__(self, debug=False, lexer_class=None):
+        if self.__doc__ == None:
+            raise Exception('Docstrings have been removed! By design of PLY, jsonpath-rw requires docstrings. You must not use PYTHONOPTIMIZE=2 or python -OO.')
+
+        self.debug = debug
+        self.lexer_class = lexer_class or JsonPathLexer # Crufty but works around statefulness in PLY
+
+    def parse(self, string, lexer = None):
+        lexer = lexer or self.lexer_class()
+        return self.parse_token_stream(lexer.tokenize(string))
+
+    def parse_token_stream(self, token_iterator, start_symbol='jsonpath'):
+
+        # Since PLY has some crufty aspects and dumps files, we try to keep them local
+        # However, we need to derive the name of the output Python file :-/
+        output_directory = os.path.dirname(__file__)
+        try:
+            module_name = os.path.splitext(os.path.split(__file__)[1])[0]
+        except:
+            module_name = __name__
+        
+        parsing_table_module = '_'.join([module_name, start_symbol, 'parsetab'])
+
+        # And we regenerate the parse table every time; it doesn't actually take that long!
+        new_parser = ply.yacc.yacc(module=self,
+                                   debug=self.debug,
+                                   tabmodule = parsing_table_module,
+                                   outputdir = output_directory,
+                                   write_tables=0,
+                                   start = start_symbol,
+                                   errorlog = logger)
+
+        return new_parser.parse(lexer = IteratorToTokenStream(token_iterator))
+
+    # ===================== PLY Parser specification =====================
+    
+    precedence = [
+        ('left', ','),
+        ('left', 'DOUBLEDOT'),
+        ('left', '.'),
+        ('left', '|'),
+        ('left', '&'),
+        ('left', 'WHERE'),
+    ]
+
+    def p_error(self, t):
+        raise Exception('Parse error at %s:%s near token %s (%s)' % (t.lineno, t.col, t.value, t.type)) 
+
+    def p_jsonpath_binop(self, p):
+        """jsonpath : jsonpath '.' jsonpath 
+                    | jsonpath DOUBLEDOT jsonpath
+                    | jsonpath WHERE jsonpath
+                    | jsonpath '|' jsonpath
+                    | jsonpath '&' jsonpath"""
+        op = p[2]
+
+        if op == '.':
+            p[0] = Child(p[1], p[3])
+        elif op == '..':
+            p[0] = Descendants(p[1], p[3])
+        elif op == 'where':
+            p[0] = Where(p[1], p[3])
+        elif op == '|':
+            p[0] = Union(p[1], p[3])
+        elif op == '&':
+            p[0] = Intersect(p[1], p[3])
+
+    def p_jsonpath_fields(self, p):
+        "jsonpath : fields_or_any"
+        p[0] = Fields(*p[1])
+
+    def p_jsonpath_named_operator(self, p):
+        "jsonpath : NAMED_OPERATOR"
+        if p[1] == 'this':
+            p[0] = This()
+        elif p[1] == 'parent':
+            p[0] = Parent()
+        else:
+            raise Exception('Unknown named operator `%s` at %s:%s' % (p[1], p.lineno(1), p.lexpos(1)))
+
+    def p_jsonpath_root(self, p):
+        "jsonpath : '$'"
+        p[0] = Root()
+
+    def p_jsonpath_idx(self, p):
+        "jsonpath : '[' idx ']'"
+        p[0] = p[2]
+
+    def p_jsonpath_slice(self, p):
+        "jsonpath : '[' slice ']'"
+        p[0] = p[2]
+
+    def p_jsonpath_fieldbrackets(self, p):
+        "jsonpath : '[' fields ']'"
+        p[0] = Fields(*p[2])
+
+    def p_jsonpath_child_fieldbrackets(self, p):
+        "jsonpath : jsonpath '[' fields ']'"
+        p[0] = Child(p[1], Fields(*p[3]))
+
+    def p_jsonpath_child_idxbrackets(self, p):
+        "jsonpath : jsonpath '[' idx ']'"
+        p[0] = Child(p[1], p[3])
+
+    def p_jsonpath_child_slicebrackets(self, p):
+        "jsonpath : jsonpath '[' slice ']'"
+        p[0] = Child(p[1], p[3])
+
+    def p_jsonpath_parens(self, p):
+        "jsonpath : '(' jsonpath ')'"
+        p[0] = p[2]
+
+    # Because fields in brackets cannot be '*' - that is reserved for array indices
+    def p_fields_or_any(self, p):
+        """fields_or_any : fields 
+                         | '*'    """
+        if p[1] == '*':
+            p[0] = ['*']
+        else:
+            p[0] = p[1]
+
+    def p_fields_id(self, p):
+        "fields : ID"
+        p[0] = [p[1]]
+
+    def p_fields_comma(self, p):
+        "fields : fields ',' fields"
+        p[0] = p[1] + p[3]
+
+    def p_idx(self, p):
+        "idx : NUMBER"
+        p[0] = Index(p[1])
+
+    def p_slice_any(self, p):
+        "slice : '*'"
+        p[0] = Slice()
+
+    def p_slice(self, p): # Currently does not support `step`
+        "slice : maybe_int ':' maybe_int"
+        p[0] = Slice(start=p[1], end=p[3])
+
+    def p_maybe_int(self, p):
+        """maybe_int : NUMBER
+                     | empty"""
+        p[0] = p[1]
+    
+    def p_empty(self, p):
+        'empty :'
+        p[0] = None
+
+class IteratorToTokenStream(object):
+    def __init__(self, iterator):
+        self.iterator = iterator
+
+    def token(self):
+        try:
+            return next(self.iterator)
+        except StopIteration:
+            return None
+
+
+if __name__ == '__main__':
+    logging.basicConfig()
+    parser = JsonPathParser(debug=True)
+    print(parser.parse(sys.stdin.read()))