Implement Liquid 5.0.0 language features

[robin-parker]

Dotliquid version

2.1.457

Expected behavior

Implement Liquid 5.0.0 language features, including:

• Add {% liquid %} and {% echo %} tags Shopify/liquid#1086
• Add new {% render %} tag Shopify/liquid#1122
• Named parameters as supported by the default filter and render template tag.
  • Allow default function to handle false as value Shopify/liquid#1144

Actual behavior

Not yet implemented.

Steps to reproduce the Problem (you can add files)

Not applicable

[microalps]

Should this be a placeholder for all 5.0 features missing? I mentioned a few new tags in the wiki.

Also, the entire concept of named parameters in liquid filters doesn't exist AFAIK, so we need to add the infrastructure for it. Is this the only such case?

[robin-parker]

Makes sense to have a placeholder for 5.0.0 for tracking the feature gaps, the Liquid change history categorizes Shopify/liquid#1144 as a fix, rather than a new feature.

allow_false: is the only case of a named parameter that I could find.

[MarioMajcicaAtABNAMRO]

Any progress on this?