From aa2c89d8b9fd27966d476d10f066bfbd276838d3 Mon Sep 17 00:00:00 2001
From: Stephan Seitz <stephan.seitz@fau.de>
Date: Thu, 22 Nov 2018 14:23:09 +0100
Subject: [PATCH] More robust parsing of ps.fields() string
---
field.py | 104 ++++++++++++++++++++++++++++++++-----------------------
1 file changed, 60 insertions(+), 44 deletions(-)
diff --git a/field.py b/field.py
index 20501752a..03bcb0fec 100644
--- a/field.py
+++ b/field.py
@@ -3,6 +3,7 @@ from itertools import chain
from typing import Tuple, Sequence, Optional, List, Set
import numpy as np
import sympy as sp
+import re
from sympy.core.cache import cacheit
from pystencils.alignedarray import aligned_empty
from pystencils.data_types import create_type, StructType
@@ -730,53 +731,68 @@ def compute_strides(shape, layout):
return tuple(strides)
-def _parse_type_description(type_description):
- if not type_description:
- return np.float64, None
- elif '[' in type_description:
- assert type_description[-1] == ']'
- type_part, size_part = type_description[:-1].split("[", )
- if not type_part:
- type_part = "float64"
- if size_part.lower()[-1] == 'd':
- size_part = int(size_part[:-1])
- else:
- size_part = tuple(int(i) for i in size_part.split(','))
- else:
- type_part, size_part = type_description, None
-
- dtype = np.dtype(type_part).type
- return dtype, size_part
-
-
-def _parse_field_description(description):
- if '(' not in description:
- return description, ()
- assert description[-1] == ')'
- name, index_shape = description[:-1].split('(')
- index_shape = tuple(int(i) for i in index_shape.split(','))
- return name, index_shape
+# ---------------------------------------- Parsing of string in fields() function --------------------------------------
+
+field_description_regex = re.compile(r"""
+ \s* # ignore leading white spaces
+ (\w+) # identifier is a sequence of alphanumeric characters, is stored in first group
+ (?: # optional index specification e.g. (1, 4, 2)
+ \s*
+ \(
+ ([^\)]+) # read everything up to closing bracket
+ \)
+ \s*
+ )?
+ \s*,?\s* # ignore trailing white spaces and comma
+""", re.VERBOSE)
+
+type_description_regex = re.compile(r"""
+ \s*
+ (\w+)? # optional dtype
+ \s*
+ \[
+ ([^\]]+)
+ \]
+ \s*
+""", re.VERBOSE | re.IGNORECASE)
def _parse_description(description):
- description = description.replace(' ', '')
+ def parse_part1(d):
+ result = field_description_regex.match(d)
+ while result:
+ name, index_str = result[1], result[2]
+ index = tuple(int(e) for e in index_str.split(",")) if index_str else ()
+ yield name, index
+ d = d[result.end():]
+ result = field_description_regex.match(d)
+
+ def parse_part2(d):
+ result = type_description_regex.match(d)
+ if result:
+ data_type_str, size_info = result[1], result[2].strip().lower()
+ if data_type_str is None:
+ data_type_str = 'float64'
+ data_type_str = data_type_str.lower().strip()
+
+ if not data_type_str:
+ data_type_str = 'float64'
+ if size_info.endswith('d'):
+ size_info = int(size_info[:-1])
+ else:
+ size_info = tuple(int(e) for e in size_info.split(","))
+ return data_type_str, size_info
+ else:
+ raise ValueError("Could not parse field description")
+
if ':' in description:
- name_descr, type_descr = description.split(':')
+ field_description, field_info = description.split(':')
else:
- name_descr, type_descr = description, ''
-
- # correct ',' splits inside brackets
- field_names = name_descr.split(',')
- cleaned_field_names = []
- prefix = ''
- for field_name in field_names:
- full_field_name = prefix + field_name
- if '(' in full_field_name and ')' not in full_field_name:
- prefix += field_name + ','
- else:
- prefix = ''
- cleaned_field_names.append(full_field_name)
+ field_description, field_info = description, 'float64[2D]'
+
+ fields_info = [e for e in parse_part1(field_description)]
+ if not field_info:
+ raise ValueError("Could not parse field description")
- dtype, size = _parse_type_description(type_descr)
- fields_info = tuple(_parse_field_description(fd) for fd in cleaned_field_names)
- return fields_info, dtype, size
+ data_type, size = parse_part2(field_info)
+ return fields_info, data_type, size
--
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