The textwrap crate uses a simpler linear-time algorithm for wrapping
the text. The current algorithm in wrap_help uses several O(n) calls
to String::insert and String::remove, which makes it potentially
quadratic in complexity.
Comparing the 05_ripgrep benchmark at commits textwrap~2 and textwrap
gives this result on my machine:
name before ns/iter after ns/iter diff ns/iter diff %
build_app_long 22,101 21,099 -1,002 -4.53%
build_app_short 22,138 21,205 -933 -4.21%
build_help_long 514,265 284,467 -229,798 -44.68%
build_help_short 85,720 85,693 -27 -0.03%
parse_clean 23,471 22,859 -612 -2.61%
parse_complex 29,535 28,919 -616 -2.09%
parse_lots 422,815 414,577 -8,238 -1.95%
As part of this commit, the wrapping_newline_chars test was updated.
The old algorithm had a subtle bug where it would break lines too
early. That is, it wrapped the text like
ARGS:
<mode> x, max, maximum 20 characters, contains
symbols.
l, long Copy-friendly,
14 characters, contains symbols.
m, med, medium Copy-friendly, 8
characters, contains symbols.";
when it should really have wrapped it like
ARGS:
<mode> x, max, maximum 20 characters, contains
symbols.
l, long Copy-friendly, 14
characters, contains symbols.
m, med, medium Copy-friendly, 8
characters, contains symbols.";
Notice how the word "14" was incorrectly moved to the next line. There
is clearly room for the word on the line with the "l, long" option
since there is room for "contains" just above it.
I'm not sure why this is, but the algorithm in textwrap handles this
case correctly.
* tests: adds tests for default values triggering conditional requirements
* fix: fixes a bug where default values should have triggered a conditional requirement but didnt
Closes#831
* tests: adds tests for missing conditional requirements in usage string of errors
* fix: fixes a bug where conditionally required args werent appearing in errors
* tests: adds tests for completion generators
* tests: adds tests for completions with binaries names that have underscores
* fix: fixes a bug where ZSH completions would panic if the binary name had an underscore in it
Closes#581
* fix: fixes bash completions for commands that have an underscore in the name
Closes#581
* chore: fix the category for crates.io
* docs(Macros): adds a warning about changing values in Cargo.toml not triggering a rebuild automatically
Closes#838
* fix(Completions): fixes a bug where global args weren't included in the generated completion scripts
Closes#841
* fix: fixes a println->debugln typo
* chore: increase version
Before, inserting a newline did not move the prev_space index forward.
This meant that the next word was measured incorrectly since the
length was measured back to the word before the newly inserted
linebreak.
Fixes#828.
Before, wrapping the help text at, say, 80 characters really meant
that every line could be at most 79 characters wide.
Lines can now be up to and including avail_chars columns wide.
If needed, a desired margin or padding can be subtracted from the
avail_chars argument at a later point.
* tests: remove unnecessary mut
When building the projec, I was told
warning: variable does not need to be mutable, #[warn(unused_mut)]
on by default
--> tests/macros.rs:39:9
|
39 | let mut app = clap_app!(("app name with spaces-and-hyphens") =>
| ^^^^^^^
* examples: remove unused variable
The inner Some value is not used in the match arm:
warning: unused variable: `local_matches`,
#[warn(unused_variables)] on by default
--> examples/20_subcommands.rs:128:32
|
128 | ("local", Some(local_matches)) =>{
| ^^^^^^^^^^^^^
