https://github.com/python/cpython/commit/4cc82ffa377db5073fdc6f85c6f35f9c47397796
commit: 4cc82ffa377db5073fdc6f85c6f35f9c47397796
branch: main
author: Łukasz Langa <luk...@langa.pl>
committer: ambv <luk...@langa.pl>
date: 2025-03-21T18:27:35+01:00
summary:
gh-131507: Refactor screen and cursor position calculations (GH-131547)
This is based off #131509.
files:
M Lib/_pyrepl/reader.py
M Lib/_pyrepl/types.py
M Lib/_pyrepl/utils.py
diff --git a/Lib/_pyrepl/reader.py b/Lib/_pyrepl/reader.py
index b38f0bf82db331..7fc2422dac9c3f 100644
--- a/Lib/_pyrepl/reader.py
+++ b/Lib/_pyrepl/reader.py
@@ -25,12 +25,11 @@
from contextlib import contextmanager
from dataclasses import dataclass, field, fields
-import unicodedata
from _colorize import can_colorize, ANSIColors
from . import commands, console, input
-from .utils import wlen, unbracket, str_width
+from .utils import wlen, unbracket, disp_str
from .trace import trace
@@ -39,36 +38,6 @@
from .types import Callback, SimpleContextManager, KeySpec, CommandName
-def disp_str(buffer: str) -> tuple[str, list[int]]:
- """disp_str(buffer:string) -> (string, [int])
-
- Return the string that should be the printed representation of
- |buffer| and a list detailing where the characters of |buffer|
- get used up. E.g.:
-
- >>> disp_str(chr(3))
- ('^C', [1, 0])
-
- """
- b: list[int] = []
- s: list[str] = []
- for c in buffer:
- if c == '\x1a':
- s.append(c)
- b.append(2)
- elif ord(c) < 128:
- s.append(c)
- b.append(1)
- elif unicodedata.category(c).startswith("C"):
- c = r"\u%04x" % ord(c)
- s.append(c)
- b.append(len(c))
- else:
- s.append(c)
- b.append(str_width(c))
- return "".join(s), b
-
-
# syntax classes:
SYNTAX_WHITESPACE, SYNTAX_WORD, SYNTAX_SYMBOL = range(3)
@@ -347,14 +316,12 @@ def calc_screen(self) -> list[str]:
pos -= offset
prompt_from_cache = (offset and self.buffer[offset - 1] != "\n")
-
lines = "".join(self.buffer[offset:]).split("\n")
-
cursor_found = False
lines_beyond_cursor = 0
for ln, line in enumerate(lines, num_common_lines):
- ll = len(line)
- if 0 <= pos <= ll:
+ line_len = len(line)
+ if 0 <= pos <= line_len:
self.lxy = pos, ln
cursor_found = True
elif cursor_found:
@@ -368,34 +335,34 @@ def calc_screen(self) -> list[str]:
prompt_from_cache = False
prompt = ""
else:
- prompt = self.get_prompt(ln, ll >= pos >= 0)
+ prompt = self.get_prompt(ln, line_len >= pos >= 0)
while "\n" in prompt:
pre_prompt, _, prompt = prompt.partition("\n")
last_refresh_line_end_offsets.append(offset)
screen.append(pre_prompt)
screeninfo.append((0, []))
- pos -= ll + 1
- prompt, lp = self.process_prompt(prompt)
- l, l2 = disp_str(line)
- wrapcount = (wlen(l) + lp) // self.console.width
- if wrapcount == 0:
- offset += ll + 1 # Takes all of the line plus the newline
+ pos -= line_len + 1
+ prompt, prompt_len = self.process_prompt(prompt)
+ chars, char_widths = disp_str(line)
+ wrapcount = (sum(char_widths) + prompt_len) // self.console.width
+ trace("wrapcount = {wrapcount}", wrapcount=wrapcount)
+ if wrapcount == 0 or not char_widths:
+ offset += line_len + 1 # Takes all of the line plus the
newline
last_refresh_line_end_offsets.append(offset)
- screen.append(prompt + l)
- screeninfo.append((lp, l2))
+ screen.append(prompt + "".join(chars))
+ screeninfo.append((prompt_len, char_widths))
else:
- i = 0
- while l:
- prelen = lp if i == 0 else 0
+ pre = prompt
+ prelen = prompt_len
+ for wrap in range(wrapcount + 1):
index_to_wrap_before = 0
column = 0
- for character_width in l2:
- if column + character_width >= self.console.width -
prelen:
+ for char_width in char_widths:
+ if column + char_width + prelen >= self.console.width:
break
index_to_wrap_before += 1
- column += character_width
- pre = prompt if i == 0 else ""
- if len(l) > index_to_wrap_before:
+ column += char_width
+ if len(chars) > index_to_wrap_before:
offset += index_to_wrap_before
post = "\\"
after = [1]
@@ -404,11 +371,14 @@ def calc_screen(self) -> list[str]:
post = ""
after = []
last_refresh_line_end_offsets.append(offset)
- screen.append(pre + l[:index_to_wrap_before] + post)
- screeninfo.append((prelen, l2[:index_to_wrap_before] +
after))
- l = l[index_to_wrap_before:]
- l2 = l2[index_to_wrap_before:]
- i += 1
+ render = pre + "".join(chars[:index_to_wrap_before]) + post
+ render_widths = char_widths[:index_to_wrap_before] + after
+ screen.append(render)
+ screeninfo.append((prelen, render_widths))
+ chars = chars[index_to_wrap_before:]
+ char_widths = char_widths[index_to_wrap_before:]
+ pre = ""
+ prelen = 0
self.screeninfo = screeninfo
self.cxy = self.pos2xy()
if self.msg:
@@ -537,9 +507,9 @@ def setpos_from_xy(self, x: int, y: int) -> None:
pos = 0
i = 0
while i < y:
- prompt_len, character_widths = self.screeninfo[i]
- offset = len(character_widths) - character_widths.count(0)
- in_wrapped_line = prompt_len + sum(character_widths) >=
self.console.width
+ prompt_len, char_widths = self.screeninfo[i]
+ offset = len(char_widths)
+ in_wrapped_line = prompt_len + sum(char_widths) >=
self.console.width
if in_wrapped_line:
pos += offset - 1 # -1 cause backslash is not in buffer
else:
@@ -560,29 +530,33 @@ def setpos_from_xy(self, x: int, y: int) -> None:
def pos2xy(self) -> tuple[int, int]:
"""Return the x, y coordinates of position 'pos'."""
- # this *is* incomprehensible, yes.
- p, y = 0, 0
- l2: list[int] = []
+
+ prompt_len, y = 0, 0
+ char_widths: list[int] = []
pos = self.pos
assert 0 <= pos <= len(self.buffer)
+
+ # optimize for the common case: typing at the end of the buffer
if pos == len(self.buffer) and len(self.screeninfo) > 0:
y = len(self.screeninfo) - 1
- p, l2 = self.screeninfo[y]
- return p + sum(l2) + l2.count(0), y
+ prompt_len, char_widths = self.screeninfo[y]
+ return prompt_len + sum(char_widths), y
+
+ for prompt_len, char_widths in self.screeninfo:
+ offset = len(char_widths)
+ in_wrapped_line = prompt_len + sum(char_widths) >=
self.console.width
+ if in_wrapped_line:
+ offset -= 1 # need to remove line-wrapping backslash
- for p, l2 in self.screeninfo:
- l = len(l2) - l2.count(0)
- in_wrapped_line = p + sum(l2) >= self.console.width
- offset = l - 1 if in_wrapped_line else l # need to remove
backslash
if offset >= pos:
break
- if p + sum(l2) >= self.console.width:
- pos -= l - 1 # -1 cause backslash is not in buffer
- else:
- pos -= l + 1 # +1 cause newline is in buffer
+ if not in_wrapped_line:
+ offset += 1 # there's a newline in buffer
+
+ pos -= offset
y += 1
- return p + sum(l2[:pos]), y
+ return prompt_len + sum(char_widths[:pos]), y
def insert(self, text: str | list[str]) -> None:
"""Insert 'text' at the insertion point."""
diff --git a/Lib/_pyrepl/types.py b/Lib/_pyrepl/types.py
index f9d48b828c720b..c5b7ebc1a406bd 100644
--- a/Lib/_pyrepl/types.py
+++ b/Lib/_pyrepl/types.py
@@ -1,8 +1,10 @@
from collections.abc import Callable, Iterator
-Callback = Callable[[], object]
-SimpleContextManager = Iterator[None]
-KeySpec = str # like r"\C-c"
-CommandName = str # like "interrupt"
-EventTuple = tuple[CommandName, str]
-Completer = Callable[[str, int], str | None]
+type Callback = Callable[[], object]
+type SimpleContextManager = Iterator[None]
+type KeySpec = str # like r"\C-c"
+type CommandName = str # like "interrupt"
+type EventTuple = tuple[CommandName, str]
+type Completer = Callable[[str, int], str | None]
+type CharBuffer = list[str]
+type CharWidths = list[int]
diff --git a/Lib/_pyrepl/utils.py b/Lib/_pyrepl/utils.py
index 0eb5f8c0097f41..7437fbe1ab9371 100644
--- a/Lib/_pyrepl/utils.py
+++ b/Lib/_pyrepl/utils.py
@@ -2,6 +2,9 @@
import unicodedata
import functools
+from .types import CharBuffer, CharWidths
+from .trace import trace
+
ANSI_ESCAPE_SEQUENCE = re.compile(r"\x1b\[[ -@]*[A-~]")
ZERO_WIDTH_BRACKET = re.compile(r"\x01.*?\x02")
ZERO_WIDTH_TRANS = str.maketrans({"\x01": "", "\x02": ""})
@@ -36,3 +39,39 @@ def unbracket(s: str, including_content: bool = False) ->
str:
if including_content:
return ZERO_WIDTH_BRACKET.sub("", s)
return s.translate(ZERO_WIDTH_TRANS)
+
+
+def disp_str(buffer: str) -> tuple[CharBuffer, CharWidths]:
+ r"""Decompose the input buffer into a printable variant.
+
+ Returns a tuple of two lists:
+ - the first list is the input buffer, character by character;
+ - the second list is the visible width of each character in the input
+ buffer.
+
+ Examples:
+ >>> utils.disp_str("a = 9")
+ (['a', ' ', '=', ' ', '9'], [1, 1, 1, 1, 1])
+ """
+ chars: CharBuffer = []
+ char_widths: CharWidths = []
+
+ if not buffer:
+ return chars, char_widths
+
+ for c in buffer:
+ if c == "\x1a": # CTRL-Z on Windows
+ chars.append(c)
+ char_widths.append(2)
+ elif ord(c) < 128:
+ chars.append(c)
+ char_widths.append(1)
+ elif unicodedata.category(c).startswith("C"):
+ c = r"\u%04x" % ord(c)
+ chars.append(c)
+ char_widths.append(len(c))
+ else:
+ chars.append(c)
+ char_widths.append(str_width(c))
+ trace("disp_str({buffer}) = {s}, {b}", buffer=repr(buffer), s=chars,
b=char_widths)
+ return chars, char_widths
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