Extend ordering comparisons (< , <=, etc) to Bool & Character

[darkdrag00nv2]

Work towards #2276

Description

This PR does the following:

• Extracts comparison related interface methods to a new interface ComparableValue
• Adds IsComparable to the type interface
• Updates the checker to use the IsComparable method to detemine comparability
• Implements the comparison support for Bool and Character

Support for String can be done as a follow up.

TODOs before this is ready for review:

• Fix tests for numbers
• Add tests for bool & character
• Update documentation

---

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[codecov]

Codecov Report

Merging #2430 (213c480) into master (2bb742f) will decrease coverage by 0.23%.
The diff coverage is 48.08%.

@@            Coverage Diff             @@
##           master    #2430      +/-   ##
==========================================
- Coverage   78.52%   78.29%   -0.23%     
==========================================
  Files         315      325      +10     
  Lines       68655    72464    +3809     
==========================================
+ Hits        53908    56737    +2829     
- Misses      12942    13644     +702     
- Partials     1805     2083     +278     

Flag	Coverage Δ
unittests	78.29% <48.08%> (-0.23%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
runtime/sema/block.gen.go	100.00% <ø> (ø)
runtime/sema/character.gen.go	100.00% <ø> (ø)
runtime/sema/deployedcontract.gen.go	100.00% <ø> (ø)
runtime/sema/meta_type.go	100.00% <ø> (ø)
runtime/sema/path_type.go	100.00% <ø> (ø)
runtime/sema/storable_type.go	100.00% <ø> (ø)
runtime/sema/string_type.go	95.87% <ø> (ø)
runtime/sema/type.go	89.32% <13.33%> (-0.59%)	⬇️
runtime/interpreter/value.go	69.57% <35.00%> (-0.02%)	⬇️
runtime/sema/gen/main.go	89.34% <44.44%> (-0.38%)	⬇️
... and 3 more

... and 26 files with indirect coverage changes

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[bluesign]

does comparable make sense for Bool ? I don't have much CS background but kind of makes no sense to me.

[darkdrag00nv2]

@bluesign Yeah, I am not 100% on its usefulness. However, Kotlin does support comparison for booleans. See the discussion on the issue #2276.

[bluesign]

I think it is a bit problematic; ( more headache )

a>true -> meaningless  ( prone to mistake, probably need to reject anyway ) 
a<false -> meaningless ( prone to mistake, probably need to reject anyway ) 
a>=true -> a==true
a<=false -> a==false 
a>false  -> a==true
a<true  -> a==false 

basically anything we compare with a constant, should be handled by ==

Some can say maybe it can be useful for sorting array of anystruct or something, but I think gain is minimal there. ( as we will not be able to compare false to 42 for example )

[darkdrag00nv2]

@turbolent Thoughts on the above comment?

[darkdrag00nv2]

Still need to add tests for the execution logic but opened it up for review for feedback.

[turbolent]

Nice!

[darkdrag00nv2]

Update on the PR:

• Resolved the review suggestions
• Added interpreter tests for char and bool
• Included upper and lowercase character comparison example in the documentation

[turbolent]

Nice!

[turbolent]

@SupunS Could you also please have a look when you have time? Thanks!

[darkdrag00nv2]

@SupunS Gentle reminder 🙂

[turbolent]

@dsainati1 Could you also please review the latest changes?

[SupunS]

Looks good! Just one question and a nitpick.

Sorry for taking so long for the review! Appreciate the patience 🙏