Reduce temporary objects during variable/filter parsing
Optimize block parsing -- don't recreate delimiter, use strings instead of regex
Remove block in favour of for loop to reduce temporary object allocation during variable context resolution
Merge pull request #385 from Shopify/optimize_scope_variable_resolution

Remove block in favour of for loop to reduce temporary object allocation during variable context resolution
Merge pull request #386 from Shopify/optimize_variable_parsing

Reduce temporary objects during variable/filter parsing
Merge pull request #384 from Shopify/optimize_block_parsing

Optimize block parsing -- don't recreate delimiter, use strings instead of regex
Extract parsing out of Context#resolve.
Use each_index instead of each_with_index to avoid object allocations.