WIP3

[charlespwd]

Features

• Add support for boolean expressions everywhere
  • As variable output {{ a or b }}
  • As filter argument {{ collection | where: 'prop', a or b }}
  • As tag argument {% render 'snip', enabled: a or b %}
  • As conditional tag argument {% if cond %} (extending previous behaviour)
• Add support for subexpression prioritization and associativity
  • In ascending order of priority:
    • Logical: and, or (right to left)
    • Equality: ==, !=, <> (left to right)
    • Comparison: >, >=, <, <=, contains (left to right)
    • Groupings: ( expr )
  • For example, this is now supported
    • {{ a > b == c < d or e == f }} which is equivalent to
    • {{ ((a > b) == (c < d)) or (e == f) }}

• Add support for parenthesized expressions
  • e.g. (a or b) == c

Notable passing test

  def test_assign_boolean_expression_assignment
    assert_template_result(
      'it rendered',
      <<~LIQUID,
        {%- assign should_render = a == 0 or (b == 1 and c == 2) -%}
        {%- if should_render -%}
          it rendered
        {%- endif -%}
      LIQUID
      { 'b' => 1, 'c' => 2 },
    )
  end