feat: implement Display for Expr

[parkma99]

#55
Hello @waynexia , is #55 requesting impl fmt for Expr??😕

[yuanbohan]

close #55 Hello @waynexia , is #55 requesting impl fmt for Expr??😕

It should be fmt::Display, but I got your idea. 😄

[parkma99]

Hello @yuanbohan , Current not passed test cases is below.

Case 1 :

left: `"a offset 1m"`,
 right: `"a offset 60s"`',

Case 2:

 left: `"a - on (b) group_left (x, y) c"`,
 right: `"a - on (b) group_left (y, x) c"`'

Case 1 because of Duration not imply fmt:Display, then I found a Crate duration_string, Is it need to imported?

Case 2 because of output is no ordered.

[yuanbohan]

Case 1 because of Duration not imply fmt:Display, then I found a Crate duration_string, Is it need to imported?

Go ahead, and if it is ok for you, you can commit it in a separated PR, and I will merge it ASAP if it does not break any of the exist test cases

[yuanbohan]

Please note that #71 has fixed a bug, which may cause this PR conflicted

[parkma99]

{__name__="a"}
a @ 10
is now failed to pass test cases from https://github.com/prometheus/prometheus/blob/main/promql/parser/printer_test.go

[yuanbohan]

hi @parkma99, is this PR ready? or half done with some features to do in next PR? Or if you do not have enough time, I can continue your work to make rest of the test cases passed.
Thanks for your time and ideas ❤️

[parkma99]

or if you do not have enough time, I can continue your work to make rest of the test cases passed.

Thanks you @yuanbohan Recently I work on my paper and job hunting.

[codecov]

Codecov Report

Merging #69 (b7aa7a1) into main (7213b6c) will decrease coverage by 0.01%.
The diff coverage is 99.01%.

Changes have been made to critical files, which contain lines commonly executed in production. Learn more

@@            Coverage Diff             @@
##             main      #69      +/-   ##
==========================================
- Coverage   98.63%   98.63%   -0.01%     
==========================================
  Files          12       13       +1     
  Lines        4921     5358     +437     
==========================================
+ Hits         4854     5285     +431     
- Misses         67       73       +6     

Impacted Files	Coverage Δ
src/label/mod.rs	98.52% <98.52%> (ø)
src/parser/ast.rs Critical	96.14% <98.65%> (+1.10%)	⬆️
src/label/matcher.rs	100.00% <100.00%> (ø)
src/parser/function.rs	100.00% <100.00%> (ø)
src/parser/parse.rs Critical	99.95% <100.00%> (-0.01%)	⬇️
src/util/duration.rs	100.00% <100.00%> (ø)
src/util/mod.rs	100.00% <100.00%> (ø)
src/util/visitor.rs	92.43% <100.00%> (ø)

... and 1 file with indirect coverage changes

[waynexia]

LGTM

[evenyag]

Rest LGTM.

[evenyag]

LGTM