Make array elements lowercase with Liquid filters for sorting

Question

I can't figure out how case-insesitively to sort an array containing strings: ["A", "C", "E", "b", "d"] into ["A", "b", "C", "d", "E"] .

{% assign input = "A,C,E,b,d" | split:"," %}
{{ input | join: "-" }}
{{ input | map: 'downcase' | join: "-" }}
{{ input | map: 'downcase' | sort | join: "-" }}
{{ input | map: 'length' | join: "-" }}
{{ input | map: 'size' | join: "-" }}

What am I missing about map: ?

Expected output:

A-C-E-b-d
a-c-e-b-d
a-b-c-d-e
1-1-1-1-1
1-1-1-1-1

Actual output:

A-C-E-b-d
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Note: at first I tried map: downcase (without quotes), but got no implicit conversion from nil to integer .

Answer 1

sort_natural was added after I asked the question. See other answer. I'll leave this answer here, because it shows how can you do a sorting by any key.

{% assign input = "A,C,E,b,d" | split:"," %}
{% capture intermediate %}{% for entry in input %}{{ entry | downcase }}{{ entry }}{% unless forloop.last %}{% endunless %}{% endfor %}{% endcapture %}
{% assign intermediate_sorted = intermediate | split:'' | sort %}
{% capture sorted %}{% for entry in intermediate_sorted %}{{ entry | split: '' | last }}{% unless forloop.last %}{% endunless %}{% endfor %}{% endcapture %}
{% assign sorted = sorted | split: '' %}
{{ sorted | join: "-" }}

will output AbCdE .

The US ( Unit Separator , \ , not \␟ ) and RS ( Record Separator , \ , not \␞ ) are the two characters unlikely to appear in the input, so they can be used safely most of the time. They could be , and | if you want to sort CSS IDs for example.

Answer 2

The sort_natural filter does a case-insensitive sort:

{% assign my_array = "zebra, octopus, giraffe, Sally Snake" | split: ", " %}

{{ my_array | sort_natural | join: ", " }}

Outputs giraffe, octopus, Sally Snake, zebra