Add option --remove_pg_catalog_from_functions

pglast/__main__.py

@@ -40,6 +40,7 @@ def workhorse(args):
                 split_string_literals_threshold=args.split_string_literals,
                 special_functions=args.special_functions,
                 comma_at_eoln=args.comma_at_eoln,
+                remove_pg_catalog_from_functions=args.remove_pg_catalog_from_functions,
                 semicolon_after_last_statement=args.semicolon_after_last_statement)
         except Error as e:
             print()
@@ -82,6 +83,8 @@ def main(options=None):
                         default=False, help="preserve comments in the statement")
     parser.add_argument('-S', '--statement',
                         help='the SQL statement')
+    parser.add_argument('-F', '--remove-pg_catalog-from-functions', action='store_true', default=False,
+                        help='remove pg_catalog from functions')
     parser.add_argument('infile', nargs='?', type=argparse.FileType(),
                         help='a file containing the SQL statement to be pretty-printed,'
                         ' by default stdin, when not specified with --statement option')

pglast/stream.py

@@ -118,6 +118,8 @@ class RawStream(OutputStream):
            ``False`` by default, when ``True`` add a semicolon after the last statement,
            otherwise it is emitted only as a separator between multiple statements
     :param comments: optional sequence of tuples with the comments extracted from the statement
+    :param bool remove_pg_catalog_from_functions:
+           ``False`` by default, when ``True`` remove the pg_catalog schema from functions
 
     This augments :class:`OutputStream` and implements the basic machinery needed to serialize
     the *parse tree* produced by :func:`~.parser.parse_sql()` back to a textual representation,
@@ -126,7 +128,7 @@ class RawStream(OutputStream):
 
     def __init__(self, expression_level=0, separate_statements=1, special_functions=False,
                  comma_at_eoln=False, semicolon_after_last_statement=False,
-                 comments=None):
+                 comments=None, remove_pg_catalog_from_functions=False):
         super().__init__()
         self.current_column = 0
         self.expression_level = expression_level
@@ -135,6 +137,7 @@ def __init__(self, expression_level=0, separate_statements=1, special_functions=
         self.comma_at_eoln = comma_at_eoln
         self.semicolon_after_last_statement = semicolon_after_last_statement
         self.comments = comments
+        self.remove_pg_catalog_from_functions = remove_pg_catalog_from_functions
 
     def show(self, where=stderr):  # pragma: no cover
         """Emit also current expression_level and a "pointer" showing current_column."""
@@ -255,7 +258,8 @@ def _concat_nodes(self, nodes, sep=' ', are_names=False):
         """
 
         rawstream = RawStream(expression_level=self.expression_level,
-                              special_functions=self.special_functions)
+                              special_functions=self.special_functions,
+                              remove_pg_catalog_from_functions=self.remove_pg_catalog_from_functions)
         rawstream.print_list(nodes, sep, are_names=are_names, standalone_items=False)
         return rawstream.getvalue()
 
@@ -357,10 +361,25 @@ def print_node(self, node, is_name=False, is_symbol=False):
                 printer(node, self)
         self.separator()
 
+    def _is_pg_catalog_func(self, items):
+        return (
+            self.remove_pg_catalog_from_functions
+            and items.parent_attribute == 'funcname'
+            and len(items) > 1
+            and items[0].val.value == 'pg_catalog'
+            # The list contains all functions that cannot be found without an
+            # explicit pg_catalog schema. ie:
+            # position(a,b) is invalid but pg_catalog.position(a,b) is fine
+            and items[1].val.value not in ('position',)
+        )
+
     def _print_items(self, items, sep, newline, are_names=False, is_symbol=False):
+        first = 1 if self._is_pg_catalog_func(items) else 0
         last = len(items) - 1
         for idx, item in enumerate(items):
-            if idx > 0:
+            if idx < first:
+                continue
+            if idx > first:
                 if sep == ',' and self.comma_at_eoln:
                     self.write(sep)
                     if newline:

tests/test_cli.py

@@ -125,3 +125,34 @@ def test_cli_workhorse():
             assert output.getvalue() == ("SELECT EXTRACT(HOUR FROM t1.modtime)\n"
                                          "     , count(*)\n"
                                          "FROM t1\n")
+
+    in_stmt = """\
+select substring('123',2,3),
+       regexp_split_to_array('x,x,x', ','),
+       btrim('xxx'), trim('xxx'),
+       POSITION('hour' in trim(substring('xyz hour ',1,6)))
+"""
+
+    with StringIO(in_stmt) as input:
+        with UnclosableStream() as output:
+            with redirect_stdin(input), redirect_stdout(output):
+                main(['--compact-lists-margin', '100'])
+            assert output.getvalue() == """\
+SELECT pg_catalog.substring('123', 2, 3)
+     , regexp_split_to_array('x,x,x', ',')
+     , btrim('xxx')
+     , pg_catalog.btrim('xxx')
+     , pg_catalog.position(pg_catalog.btrim(pg_catalog.substring('xyz hour ', 1, 6)), 'hour')
+"""
+
+    with StringIO(in_stmt) as input:
+        with UnclosableStream() as output:
+            with redirect_stdin(input), redirect_stdout(output):
+                main(['--remove-pg_catalog-from-functions', '--compact-lists-margin', '100'])
+            assert output.getvalue() == """\
+SELECT substring('123', 2, 3)
+     , regexp_split_to_array('x,x,x', ',')
+     , btrim('xxx')
+     , btrim('xxx')
+     , pg_catalog.position(btrim(substring('xyz hour ', 1, 6)), 'hour')
+"""