1 files changed, 38 insertions, 0 deletions

diff --git a/filters/vars.lua b/filters/vars.lua
new file mode 100644
index 0000000..e60019e
--- /dev/null
+++ b/filters/vars.lua
@@ -0,0 +1,38 @@
+local vars = {}
+
+function string.split(str, sep)
+    sep = sep or '%s'
+
+    local parts = pandoc.List()
+
+    for field, s in str:gmatch("([^" .. sep .. "]*)(" .. sep .. "?)") do
+        parts:insert(field)
+        if s == "" then return parts end
+    end
+end
+
+function meta(meta) vars = meta end
+
+function str(el)
+    local prefix, varref, suffix = el.text:match('^(.*)%%(.*)%%(.*)$')
+
+    if varref then
+        local parts = varref:split(".")
+        local var = vars
+
+        for i = 1, #parts do
+            local part = parts[i]
+            local v = var[part]
+
+            if not v then return el end
+
+            var = v
+        end
+
+        if var then return pandoc.Str(prefix .. var .. suffix) end
+    end
+
+    return el
+end
+
+return { { Meta = meta }, { Str = str } }