RuDS/docs/LIQUID_FEATURE_INVENTORY.md

bDS Liquid Feature Inventory

Inventoried from the 12 default templates in the TypeScript app (src/main/engine/templates/).

Template Files Analyzed

1. single-post.liquid (main)
2. post-list.liquid (main)
3. not-found.liquid (main)
4. macros/gallery.liquid
5. macros/youtube.liquid
6. macros/vimeo.liquid
7. macros/photo-archive.liquid
8. macros/tag-cloud.liquid
9. partials/head.liquid
10. partials/menu.liquid
11. partials/menu-items.liquid
12. partials/language-switcher.liquid

Tags Used

Tag	Used In
if / endif	9 templates
elsif	post-list
else	7 templates
for / endfor	7 templates
assign	4 templates (not-found, post-list, head, single-post)
render	5 templates (menu, menu-items, not-found, post-list, single-post)

NOT Used

unless, case/when, capture, layout, include, comment, raw, increment, decrement, tablerow, cycle

Filters Used

Filter	Type	Signature
escape	Built-in	| escape
default	Built-in	| default: value
append	Built-in	| append: string
url_encode	Built-in	| url_encode
i18n	Custom	| i18n: language — translation lookup by key and language
markdown	Custom	| markdown: post.id, post_data_json_by_id, canonical_post_path_by_slug, canonical_media_path_by_source_path, language, language_prefix — markdown-to-HTML with macro expansion and link resolution (6 args)

NOT Used

date, truncate, split, join, where, group_by, map, sort, reverse, size (as pipe filter), strip, strip_html, downcase, upcase, replace, remove, first, last, abs, ceil, floor, round, plus, minus, times, divided_by, modulo

Operators

Operator	Example
==	item.href == '#', archive_context.kind == 'tag'
>	menu_items.size > 0, blog_languages.size > 1
and	menu_items and menu_items.size > 0
or	archive_context.kind == 'tag' or archive_context.kind == 'category'
blank	canonical_post_href == blank (nil/empty check)
bare truthiness	{% if html_theme_attribute %}, {% if caption %}

NOT Used

!=, <, <=, >=, contains

Property Access Patterns

Pattern	Examples
Dot notation	archive_context.kind, post.title, item.media_path, lang.is_current
.size property	menu_items.size, items.size, post_categories.size
Bracket notation (hash/map lookup)	canonical_post_path_by_slug[post.slug], tag_color_by_name[tag]

Whitespace Stripping

{%- -%} used in 3 macro templates only: photo-archive, gallery, tag-cloud.

For-Loop Features

Feature	Used?
Basic for x in collection	YES
Nested for loops	YES (photo-archive, post-list)
Recursive render in loop	YES (menu-items renders itself for children)
forloop.first / forloop.last	NO
limit / offset	NO
reversed	NO

Render Tag Usage

• Uses named parameter passing: {% render 'partials/menu-items', items: menu_items, include_calendar: true, language: language %}
• Recursive self-render: menu-items calls render 'partials/menu-items' for nested children
• Partial paths use forward-slash notation: 'partials/head', 'partials/menu'

Two-Step Dynamic i18n Keys

{% assign month_key = 'render.month.' | append: archive_context.month %} then {{ month_key | i18n: language }}

Scope Summary

The Rust Liquid implementation needs approximately 35% of the full specification:

• Tags: if/elsif/else, for, assign, render (not include)
• Built-in filters: escape, default, append, url_encode
• Custom filters: i18n (key + language), markdown (content + 6 args)
• Operators: ==, >, and, or, truthiness, blank
• Access: dot notation, .size property, bracket notation for hash/map lookups
• Whitespace stripping: {%- -%} support required