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Differential D12404

templates: extract function to `stringutil` for getting first line of text
ClosedPublic

Authored by martinvonz on Mar 25 2022, 1:38 AM.

Details

Reviewers
Alphare
Group Reviewers
hg-reviewers
Commits
rHG51aed118f9dc: templates: extract function to `stringutil` for getting first line of text
Summary

It's surprisingly hard to get the first line from a string, so let's
have our own function in stringutil for it.

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

martinvonz created this revision.Mar 25 2022, 1:38 AM
joerg.sonnenberger added a subscriber: joerg.sonnenberger.Mar 25 2022, 7:09 AM

I wonder if we shouldn't optimize for the common case of multiple lines by using find() instead. Searching for \n first and \r second (in the substring if the first got a hit) and only then slicing the result.

martinvonz added a comment.Mar 25 2022, 11:10 AM
In D12404#189921, @joerg.sonnenberger wrote:

I wonder if we shouldn't optimize for the common case of multiple lines by using find() instead. Searching for \n first and \r second (in the substring if the first got a hit) and only then slicing the result.

I was wondering the same, but it's easier said than done because Python doesn't seem to give access to the bytes used for splitting in splitlines(). I was thinking of using split() as you said, but I didn't think of using splitlines()` on the first part of the result, so thanks for the tip! I'll add a commit to the end of this stack.

Alphare accepted this revision.Apr 6 2022, 5:51 AM
This revision is now accepted and ready to land.Apr 6 2022, 5:51 AM

Revision Contents
Changeset List

Diff 32804

mercurial/templatefilters.py

def fill76(text): def fill76(text):
"""Any text. Wraps the text to fit in 76 columns.""" """Any text. Wraps the text to fit in 76 columns."""
return fill(text, 76) return fill(text, 76)
@templatefilter(b'firstline', intype=bytes) @templatefilter(b'firstline', intype=bytes)
def firstline(text): def firstline(text):
"""Any text. Returns the first line of text.""" """Any text. Returns the first line of text."""
try: return stringutil.firstline(text)
return text.splitlines()[0]
except IndexError:
return b''
@templatefilter(b'hex', intype=bytes) @templatefilter(b'hex', intype=bytes)
def hexfilter(text): def hexfilter(text):
"""Any text. Convert a binary Mercurial node identifier into """Any text. Convert a binary Mercurial node identifier into
its long hexadecimal representation. its long hexadecimal representation.
""" """
return hex(text) return hex(text)

mercurial/utils/stringutil.py

>>> isauthorwellformed(b'<author@author.com>') >>> isauthorwellformed(b'<author@author.com>')
False False
>>> isauthorwellformed(b'Bad Author <author>') >>> isauthorwellformed(b'Bad Author <author>')
False False
""" """
return _correctauthorformat.match(author) is not None return _correctauthorformat.match(author) is not None
def firstline(text):
"""Return the first line of the input"""
try:
return text.splitlines()[0]
except IndexError:
return b''
def ellipsis(text, maxlength=400): def ellipsis(text, maxlength=400):
"""Trim string to at most maxlength (default: 400) columns in display.""" """Trim string to at most maxlength (default: 400) columns in display."""
return encoding.trim(text, maxlength, ellipsis=b'...') return encoding.trim(text, maxlength, ellipsis=b'...')
def escapestr(s): def escapestr(s):
if isinstance(s, memoryview): if isinstance(s, memoryview):
s = bytes(s) s = bytes(s)