replace Each with Iterators

[ichiban]

No description provided.

[codecov-commenter]

Codecov Report

Merging #178 (e1e63b6) into main (66a3f9f) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #178      +/-   ##
==========================================
+ Coverage   95.95%   95.97%   +0.02%     
==========================================
  Files          20       20              
  Lines        6083     6094      +11     
==========================================
+ Hits         5837     5849      +12     
+ Misses        205      204       -1     
  Partials       41       41              

Impacted Files	Coverage Δ
engine/compound.go	100.00% <ø> (ø)
engine/builtin.go	93.61% <100.00%> (ø)
engine/clause.go	97.82% <100.00%> (ø)
engine/iterator.go	100.00% <100.00%> (ø)
engine/env.go	96.77% <0.00%> (+0.64%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 66a3f9f...e1e63b6. Read the comment docs.