├── README.md
└── _extensions
    └── code-visibility
        ├── _extension.yml
        └── code-visibility.lua


/README.md:
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 1 | # Code Visibility Extension
 2 | 
 3 | This extension implements some directives for filtering code and stream
 4 | output included within a document.
 5 | 
 6 | Use this extension within a Quarto project by first installing it from within the project working directory:
 7 | 
 8 | ``` bash
 9 | quarto install extension jjallaire/code-visibility
10 | ```
11 | 
12 | Then add the `code-visibility` filter to your project:
13 | 
14 | ```yaml
15 | filters:
16 |   - code-visibility
17 | ```
18 | 
19 | ## `#| hide_line`
20 | 
21 | The `hide_line` directive hides a specific line of code in an input
22 | cell. For example, this code:
23 | 
24 | ```` python
25 | ```{python}
26 | def _secret(): ...
27 | 
28 | for i in range(3):
29 |     _secret() #| hide_line
30 |     print(i)
31 | ```
32 | ````
33 | 
34 | Becomes this:
35 | 
36 | ``` python
37 | def _secret(): ...
38 | 
39 | for i in range(3):
40 |     print(i)
41 | ```
42 | 
43 | ## `#| filter_stream: <keyword> ...`
44 | 
45 | The `filter_stream` directive filters lines containing specific keywords
46 | in cell outputs. For example, the following code:
47 | 
48 | ```` python
49 | ```{python}
50 | #| filter_stream: FutureWarning MultiIndex
51 | print('\n'.join(['A line', 'Foobar baz FutureWarning blah', 
52 |                  'zig zagMultiIndex zoom', 'Another line.']))
53 | ```
54 | ````
55 | 
56 | Produces this output:
57 | 
58 |     A line
59 |     Another line.
60 | 


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/_extensions/code-visibility/_extension.yml:
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1 | title: Code Visibility
2 | author: fast.ai
3 | version: 1.0.0
4 | contributes:
5 |   filters:
6 |     - code-visibility.lua
7 | 


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/_extensions/code-visibility/code-visibility.lua:
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 1 | 
 2 | 
 3 | 
 4 | -- remove any lines with the hide_line directive.
 5 | function CodeBlock(el)
 6 |   if el.classes:includes('cell-code') then
 7 |     el.text = filter_lines(el.text, function(line)
 8 |       return not line:match("#| ?hide_line%s*$")
 9 |     end)
10 |     return el
11 |   end
12 | end
13 | 
14 | -- apply filter_stream directive to cells
15 | function Div(el)
16 |   if el.classes:includes("cell") then
17 |     local filters = el.attributes["filter_stream"]
18 |     if filters then
19 |       -- process cell-code
20 |       return pandoc.walk_block(el, {
21 |         CodeBlock = function(el)
22 |           -- CodeBlock that isn't `cell-code` is output
23 |           if not el.classes:includes("cell-code") then
24 |             for filter in filters:gmatch("[^%s,]+") do
25 |               el.text = filter_lines(el.text, function(line)
26 |                 return not line:find(filter, 1, true)
27 |               end)
28 |             end
29 |             return el
30 |           end
31 |         end
32 |       })
33 |       
34 |     end
35 | 
36 |   end
37 |   
38 | end
39 | 
40 | function filter_lines(text, filter)
41 |   local lines = pandoc.List()
42 |   local code = text .. "\n"
43 |   for line in code:gmatch("([^\r\n]*)[\r\n]") do
44 |     if filter(line) then
45 |       lines:insert(line)
46 |     end
47 |   end
48 |   return table.concat(lines, "\n")
49 | end
50 | 
51 | 
52 | 


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