From b0a30ee84ef3c6e9505a8f872a260db373fdb641 Mon Sep 17 00:00:00 2001 From: Vivien Maisonneuve Date: Thu, 26 Jun 2014 14:36:50 +0200 Subject: [PATCH] Improve Expression.fromstring(), Domain.fromstring() --- pypol/domains.py | 29 +++++++++++++++++++---------- pypol/linexprs.py | 5 ++++- 2 files changed, 23 insertions(+), 11 deletions(-) diff --git a/pypol/domains.py b/pypol/domains.py index 20493fa..9bb403e 100644 --- a/pypol/domains.py +++ b/pypol/domains.py @@ -287,25 +287,34 @@ class Domain: return Polyhedron(equalities, inequalities) raise SyntaxError('invalid syntax') + _RE_BRACES = re.compile(r'^\{\s*|\s*\}$') + _RE_EQ = re.compile(r'([^<=>])=([^<=>])') + _RE_AND = re.compile(r'\band\b|,|&&|/\\|∧|∩') + _RE_OR = re.compile(r'\bor\b|;|\|\||\\/|∨|∪') + _RE_NOT = re.compile(r'\bnot\b|!|¬') + _RE_NUM_VAR = Expression._RE_NUM_VAR + _RE_OPERATORS = re.compile(r'(&|\||~)') + @classmethod def fromstring(cls, string): - # remove brackets - string = re.sub(r'^\{\s*|\s*\}$', '', string) + # remove curly brackets + string = cls._RE_BRACES.sub(r'', string) # replace '=' by '==' - string = re.sub(r'([^<=>])=([^<=>])', r'\1==\2', string) + string = cls._RE_EQ.sub(r'\1==\2', string) # replace 'and', 'or', 'not' - string = re.sub(r'\band\b|,|&&|/\\|∧|∩', r' & ', string) - string = re.sub(r'\bor\b|;|\|\||\\/|∨|∪', r' | ', string) - string = re.sub(r'\bnot\b|!|¬', r' ~', string) - tokens = re.split(r'(&|\||~)', string) + string = cls._RE_AND.sub(r' & ', string) + string = cls._RE_OR.sub(r' | ', string) + string = cls._RE_NOT.sub(r' ~', string) + # add implicit multiplication operators, e.g. '5x' -> '5*x' + string = cls._RE_NUM_VAR.sub(r'\1*\2', string) + # add parentheses to force precedence + tokens = cls._RE_OPERATORS.split(string) for i, token in enumerate(tokens): if i % 2 == 0: - # add implicit multiplication operators, e.g. '5x' -> '5*x' - token = re.sub(r'(\d+|\))\s*([^\W\d_]\w*|\()', r'\1*\2', token) token = '({})'.format(token) tokens[i] = token string = ''.join(tokens) - tree = ast.parse(string) + tree = ast.parse(string, 'eval') return cls._fromast(tree) def __repr__(self): diff --git a/pypol/linexprs.py b/pypol/linexprs.py index 0db7edd..9ab5c86 100644 --- a/pypol/linexprs.py +++ b/pypol/linexprs.py @@ -252,9 +252,12 @@ class Expression: return left / right raise SyntaxError('invalid syntax') + _RE_NUM_VAR = re.compile(r'(\d+|\))\s*([^\W\d_]\w*|\()') + @classmethod def fromstring(cls, string): - string = re.sub(r'(\d+|\))\s*([^\W\d_]\w*|\()', r'\1*\2', string) + # add implicit multiplication operators, e.g. '5x' -> '5*x' + string = cls._RE_NUM_VAR.sub(r'\1*\2', string) tree = ast.parse(string, 'eval') return cls._fromast(tree) -- 2.20.1