"""Tools for preparing code to be run in the REPL (removing blank lines,
etc)"""
from ..lazyre import LazyReCompile
from itertools import tee, islice, chain
# TODO specifically catch IndentationErrors instead of any syntax errors
indent_empty_lines_re = LazyReCompile(r"\s*")
tabs_to_spaces_re = LazyReCompile(r"^\t+")
def indent_empty_lines(s, compiler):
"""Indents blank lines that would otherwise cause early compilation
Only really works if starting on a new line"""
lines = s.split("\n")
ends_with_newline = False
if lines and not lines[-1]:
ends_with_newline = True
lines.pop()
result_lines = []
prevs, lines, nexts = tee(lines, 3)
prevs = chain(("",), prevs)
nexts = chain(islice(nexts, 1, None), ("",))
for p_line, line, n_line in zip(prevs, lines, nexts):
if len(line) == 0:
p_indent = indent_empty_lines_re.match(p_line).group()
n_indent = indent_empty_lines_re.match(n_line).group()
result_lines.append(min([p_indent, n_indent], key=len) + line)
else:
result_lines.append(line)
return "\n".join(result_lines) + ("\n" if ends_with_newline else "")
def leading_tabs_to_spaces(s):
lines = s.split("\n")
result_lines = []
def tab_to_space(m):
return len(m.group()) * 4 * " "
for line in lines:
result_lines.append(tabs_to_spaces_re.sub(tab_to_space, line))
return "\n".join(result_lines)
def preprocess(s, compiler):
return indent_empty_lines(leading_tabs_to_spaces(s), compiler)