initial commit

Author: jjallaire

.gitignore

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+*.html
+*.pdf
+*_files/
+/.luarc.json

README.md

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+# Include Code Files Extension For Quarto
+
+Filter to include code from source files.
+
+The filter is largely inspired by
+[pandoc-include-code](https://github.com/owickstrom/pandoc-include-code).
+
+## Installing
+
+```bash
+quarto add quarto-ext/include-code-files
+```
+
+This will install the extension under the `_extensions` subdirectory.
+If you're using version control, you will want to check in this directory.
+
+## Usage
+
+The filter recognizes code blocks with the `include` attribute present. It swaps the content of the code block with contents from a file.
+
+Here is how you add the filter to a page (it can also be added to a `_quarto.yml` project file with the same syntax):
+
+````markdown
+---
+title: "My Document"
+filters:
+   - include-code-files
+---
+
+````
+
+### Including Files
+
+Once adding the filter to you page or project, the simplest way to use the filter is the `include` attribute
+
+    ```{include="script.py"}
+    ```
+
+You can still use other attributes, and classes, to control the code blocks:
+
+    ```{.c include="script.py" code-line-numbers="true"}
+    ```
+
+### Ranges
+
+If you want to include a specific range of lines, use `startLine` and `endLine`:
+
+    ```{include="script.py" startLine=35 endLine=80}
+    ```
+
+`start-line` and `end-line` alternatives are also recognized.
+
+### Dedent
+
+Using the `dedent` attribute, you can have whitespaces removed on each line, where possible (non-whitespace character will not be removed even if they occur
+in the dedent area).
+
+    ```{include="script.py" dedent=4}
+    ```
+

_extensions/include-code-files/_extension.yml

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+title: Include Code Files
+author: Bruno Beaufils
+version: 1.0.0
+quarto-required: ">=1.2"
+contributes:
+  filters:
+    - include-code-files.lua
+
+

_extensions/include-code-files/include-code-files.lua

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+--- include-code-files.lua – filter to include code from source files
+---
+--- Copyright: © 2020 Bruno BEAUFILS
+--- License:   MIT – see LICENSE file for details
+
+--- Dedent a line
+local function dedent (line, n)
+  return line:sub(1,n):gsub(" ","") .. line:sub(n+1)
+end
+
+--- Filter function for code blocks
+local function transclude (cb)
+  if cb.attributes.include then
+    local content = ""
+    local fh = io.open(cb.attributes.include)
+    if not fh then
+      io.stderr:write("Cannot open file " .. cb.attributes.include .. " | Skipping includes\n")
+    else
+      local number = 1
+      local start = 1
+
+      -- change hyphenated attributes to PascalCase
+      for i,pascal in pairs({"startLine", "endLine"})
+      do
+         local hyphen = pascal:gsub("%u", "-%0"):lower()
+         if cb.attributes[hyphen] then
+            cb.attributes[pascal] = cb.attributes[hyphen]
+            cb.attributes[hyphen] = nil
+         end
+      end
+
+      if cb.attributes.startLine then
+        cb.attributes.startFrom = cb.attributes.startLine
+        start = tonumber(cb.attributes.startLine)
+      end
+      for line in fh:lines ("L")
+      do
+        if cb.attributes.dedent then
+          line = dedent(line, cb.attributes.dedent)
+        end
+        if number >= start then
+          if not cb.attributes.endLine or number <= tonumber(cb.attributes.endLine) then
+            content = content .. line
+          end
+        end
+        number = number + 1
+      end 
+      fh:close()
+    end     
+    -- remove key-value pair for used keys
+    cb.attributes.include = nil
+    cb.attributes.startLine = nil
+    cb.attributes.endLine = nil
+    cb.attributes.dedent = nil
+    -- return final code block
+    return pandoc.CodeBlock(content, cb.attr)
+  end
+end
+
+return {
+  { CodeBlock = transclude }
+}
+