diff options
Diffstat (limited to 'prolog')
| -rw-r--r-- | prolog/util.py | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/prolog/util.py b/prolog/util.py index e682edb..83f891f 100644 --- a/prolog/util.py +++ b/prolog/util.py @@ -16,6 +16,8 @@ from collections import namedtuple from collections.abc import Iterable +import string + from nltk import Tree # Stores a token's type and value, and optionally the position of the first @@ -78,6 +80,13 @@ def stringify(obj): return ''.join([stringify(child) for child in obj]) + '\n' return ''.join([stringify(child) for child in obj]) +# Return a canonical name for the [n]th variable in scope. +def canonical_varname(n): + names = string.ascii_uppercase + if n < len(names): + return names[n] + return 'X{}'.format(n) + # Rename variables in [tokens] to A0, A1, A2,… in order of appearance. def rename_vars_list(tokens, names=None): if names is None: @@ -90,7 +99,7 @@ def rename_vars_list(tokens, names=None): if t.type == 'VARIABLE' and t.val != '_': cur_name = t.val if cur_name not in names: - names[cur_name] = 'A{}'.format(next_id) + names[cur_name] = canonical_varname(next_id) next_id += 1 tokens[i] = t.clone(val=names[cur_name]) return tokens @@ -115,7 +124,7 @@ def rename_vars_ast(root, fixed_names=None): if node.type == 'VARIABLE': token = node if token.val.startswith('_'): - new_node = token.clone(val='A{}'.format(next_id)) + new_node = token.clone(val=canonical_varname(next_id)) next_id += 1 else: cur_name = token.val @@ -123,7 +132,7 @@ def rename_vars_ast(root, fixed_names=None): new_name = fixed_names[cur_name] else: if cur_name not in names: - names[cur_name] = 'A{}'.format(next_id) + names[cur_name] = canonical_varname(next_id) next_id += 1 new_name = names[cur_name] new_node = token.clone(val=new_name) |