add _extensions

_extensions/drwater/remove-spaces/_extension.yml

@@ -0,0 +1,7 @@
+title: Remove Spaces around Chinese Characters except Citations
+author: Tom Ben
+version: 1.0.0
+quarto-required: ">=1.5.0"
+contributes:
+  filters:
+    - remove-spaces.lua

_extensions/drwater/remove-spaces/remove-spaces.lua

@@ -0,0 +1,55 @@
+--- Remove spaces around Chinese characters except citations
+
+--- Copyright: © 2024–Present Tom Ben
+--- License: MIT License
+
+-- Check if the character is non-ASCII (potentially a Chinese character).
+local function is_non_ascii(char)
+  return char and string.byte(char) > 127
+end
+
+-- Process the paragraph to remove spaces adjacent to non-ASCII characters
+local function process_paragraph(para)
+  local cs = para.content
+  local new_content = {}
+
+  for i, elem in ipairs(cs) do
+    -- If the element is not a Space, always keep it
+    if elem.t ~= 'Space' then
+      table.insert(new_content, elem)
+    else
+      -- Element is a Space, determine whether to keep it
+      local next_elem = cs[i + 1]
+      local prev_elem = cs[i - 1]
+
+      -- Check adjacent characters for Chinese text
+      local next_char = next_elem and next_elem.t == 'Str' and next_elem.text:sub(1, 1)
+      local prev_char = prev_elem and prev_elem.t == 'Str' and prev_elem.text:sub(-1)
+
+      -- Check if adjacent elements are citations or citation-related elements
+      local next_is_cite = next_elem and (next_elem.t == 'Cite' or next_elem.t == 'Note')
+      local prev_is_cite = prev_elem and (prev_elem.t == 'Cite' or prev_elem.t == 'Note')
+
+      -- Determine if we need to remove this space
+      local has_adjacent_chinese = (next_char and is_non_ascii(next_char)) or (prev_char and is_non_ascii(prev_char))
+      local is_adjacent_to_cite = (prev_is_cite and next_char and is_non_ascii(next_char)) or
+          (next_is_cite and prev_char and is_non_ascii(prev_char))
+
+      -- Keep space if:
+      -- 1. It's not adjacent to Chinese characters, OR
+      -- 2. It's between a citation and Chinese characters
+      if not has_adjacent_chinese or is_adjacent_to_cite then
+        table.insert(new_content, elem)
+      end
+      -- Otherwise, remove the space (by not adding it to new_content)
+    end
+  end
+
+  para.content = new_content
+  return para
+end
+
+-- Return the filter for Pandoc
+return {
+  { Para = process_paragraph }
+}