Add validations for ERE quantifiers {m}, {m,} and {m,n}

[LoukasPap]

Fixes issue 289

There are two types of errors in quantifiers:

1. Unmatched \\{ for unterminated braces
2. Invalid content of \\{\\} for all the others

Unmatched \\{

sed always captures the unmatched braces error first. To deal with that, I scan ahead the regex for unclosed { } and if it is violated it throws the error, otherwise we retreat back to the beginning to start the processing.

Invalid content of \\{\\}

Processing happens only if we have extended mode and checks for:

• m and/or n are positive
• m <= n
• integers and comma are only allowed (the comma between m and n)
• {,} to be converted to *
• {,n} to be parsed as literal

There is also an error when m and/or n are very large numbers but I let that for the regex crate to handle (the error message is different from sed's but that is trivial I believe).

[codecov]

Codecov Report

❌ Patch coverage is 95.15152% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 82.40%. Comparing base (b5b4cef) to head (47d16fe).
⚠️ Report is 19 commits behind head on main.

Files with missing lines	Patch %	Lines
src/sed/delimited_parser.rs	94.48%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #328      +/-   ##
==========================================
+ Coverage   82.07%   82.40%   +0.33%     
==========================================
  Files          13       13              
  Lines        5445     5587     +142     
  Branches      293      307      +14     
==========================================
+ Hits         4469     4604     +135     
- Misses        974      981       +7     
  Partials        2        2              

Flag	Coverage Δ
macos_latest	82.84% <95.15%> (+0.32%)	⬆️
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[LoukasPap]

Forgot to add unit tests. I will add soon.

[codspeed-hq]

Merging this PR will improve performance by 2.42%

⚡ 1 improved benchmark
✅ 10 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	number_fix	521 ms	508.7 ms	+2.42%

---

_{Comparing LoukasPap:issue289 (47d16fe) with main (61152af)}

[LoukasPap]

@e-kwsm Ready for review! 🙂

[e-kwsm]

{,n} to be parsed as literal

nitpick: "{,n}" pattern is not specified in ERE, but

<<< xxx sed -E -n -e '/x{,-1}/s//@/p'

• GNU and BSD: Invalid content of \{\}, exit with one
• uutils: prints nothing and exits with zero

<<< xxx sed -E -n -e '/x{,0}/s//@/p'

• GNU and BSD: print @xxx
• uutils: prints nothing

<<< xxx sed -E -n -e '/x{,1}/s//@/p'

• GNU and BSD: print @xx
• uutils: prints nothing

[e-kwsm]

<<< xxx sed -n -E -e '/.{,x}/p'

• GNU and BSD: Invalid content of \{\}
• uutils: prints nothing

[e-kwsm]

There is also an error when m and/or n are very large numbers but I let that for the regex crate to handle

GNU and BSD support 255-repetition.

https://www.gnu.org/software/sed/manual/html_node/BRE-syntax.html#index-GNU-extensions_002c-to-basic-regular-expressions-2

\{i\}

As *, but matches exactly i sequences (i is a decimal integer; for portability, keep it between 0 and 255 inclusive).

https://man.freebsd.org/cgi/man.cgi?re_format(7)

A bound is `{' followed by an unsigned decimal integer, possibly followed by `,' possibly followed by another unsigned decimal integer, always followed by `}'. The integers must lie between 0 and RE_DUP_MAX (255<**>) inclusive, and if there are two of them, the first may not exceed the second.

[LoukasPap]

Nice catches, I'll check them