feat(latex): high-performance LaTeX-to-Unicode mathematical engine integration via Rust FFI

lua/markview/ffi/math.lua

@@ -0,0 +1,132 @@
+local ffi = require("ffi")
+
+ffi.cdef[[
+    int latex_register_symbols(const char *const *names, const char *const *values, unsigned int count);
+    char* latex_to_unicode(const char* input);
+    char* latex_to_unicode_block(const char* input);
+    char* latex_to_unicode_checked(const char* input, int* fully_supported);
+    char* latex_to_unicode_block_checked(const char* input, int* fully_supported);
+    char* latex_transform_markdown(const char* input);
+    void latex_unicode_free(char* ptr);
+]]
+
+local M = {}
+local lib = nil
+local symbols_registered = false
+
+local function get_lib_path()
+    local home = os.getenv("HOME")
+    local candidates = {
+        home .. "/Labs/KpihX-Labs/latex-to-unicode/target/release/liblatex_to_unicode_c_api.so",
+        home .. "/.local/lib/liblatex_to_unicode_c_api.so",
+        "/usr/local/lib/liblatex_to_unicode_c_api.so",
+    }
+    for _, path in ipairs(candidates) do
+        local f = io.open(path, "r")
+        if f then
+            f:close()
+            return path
+        end
+    end
+    return nil
+end
+
+local function register_markview_symbols()
+    local entries = require("markview.symbols").entries
+    local names = {}
+
+    for name, value in pairs(entries) do
+        if type(name) == "string" and type(value) == "string" then
+            table.insert(names, name)
+        end
+    end
+
+    table.sort(names)
+    if #names == 0 then
+        return false, "Markview symbol table is empty"
+    end
+
+    local name_buffers, value_buffers = {}, {}
+    local name_pointers = ffi.new("const char *[?]", #names)
+    local value_pointers = ffi.new("const char *[?]", #names)
+
+    for i, name in ipairs(names) do
+        local value = entries[name]
+        local name_buffer = ffi.new("char[?]", #name + 1)
+        local value_buffer = ffi.new("char[?]", #value + 1)
+        ffi.copy(name_buffer, name, #name)
+        ffi.copy(value_buffer, value, #value)
+        name_buffers[i] = name_buffer
+        value_buffers[i] = value_buffer
+        name_pointers[i - 1] = name_buffer
+        value_pointers[i - 1] = value_buffer
+    end
+
+    -- Keep the pointed-to buffers alive until Rust has copied the table.
+    local registered = lib.latex_register_symbols(name_pointers, value_pointers, #names)
+    if registered ~= 1 then
+        return false, "Rust backend rejected Markview's symbol table"
+    end
+    return true
+end
+
+function M.init()
+    if not lib then
+        local path = get_lib_path()
+        if not path then
+            return false, "liblatex_to_unicode_c_api.so not found"
+        end
+        local ok, loaded = pcall(ffi.load, path)
+        if not ok then
+            return false, loaded
+        end
+        lib = loaded
+    end
+
+    if not symbols_registered then
+        local ok, registered, err = pcall(register_markview_symbols)
+        if not ok then
+            return false, registered
+        end
+        if not registered then
+            return false, err
+        end
+        symbols_registered = true
+    end
+
+    return true
+end
+
+local function convert(latex_str, block)
+    if not M.init() then return latex_str, false end
+    local fully_supported = ffi.new("int[1]")
+    local c_str
+    if block then
+        c_str = lib.latex_to_unicode_block_checked(latex_str, fully_supported)
+    else
+        c_str = lib.latex_to_unicode_checked(latex_str, fully_supported)
+    end
+    if c_str == nil then return latex_str, false end
+    local res = ffi.string(c_str)
+    lib.latex_unicode_free(c_str)
+    return res, fully_supported[0] ~= 0
+end
+
+function M.to_unicode(latex_str)
+    return convert(latex_str, false)
+end
+
+function M.to_unicode_block(latex_str)
+    return convert(latex_str, true)
+end
+
+function M.transform_markdown(md_str)
+    if not M.init() then return md_str end
+    local c_str = lib.latex_transform_markdown(md_str)
+    if c_str == nil then return md_str end
+    local res = ffi.string(c_str)
+    lib.latex_unicode_free(c_str)
+    return res
+end
+
+return M

lua/markview/renderer.lua

@@ -386,6 +386,7 @@ end
 ---@param parsed_content markview.parsed
 renderer.render = function (buffer, parsed_content)
 	---|fS
+	parsed_content = parsed_content or {}
 
 	local _renderers = {
 		asciidoc = require("markview.renderers.asciidoc"),
@@ -427,6 +428,10 @@ renderer.render = function (buffer, parsed_content)
 
 	---|fE
 
+	if _renderers["latex"] then
+		_renderers["latex"].render(buffer, parsed_content.latex or {});
+	end
+
 	for lang, content in pairs(parsed_content) do
 		---@cast lang string
 		---@cast content