-- -- This is file `mcb.lua', -- generated with the docstrip utility. -- -- The original source files were: -- -- luatexbase-mcb.dtx (with options: `lua') -- -- Copyright (C) 2009 by Elie Roux -- -- This work is under the CC0 license. -- See source file 'luatexbase-mcb.dtx' for details. -- module('luatexbase', package.seeall) local err, warning, info = luatexbase.provides_module({ name = "luatexbase-mcb", version = 0.2, date = "2010/05/12", description = "register several functions in a callback", author = "Hans Hagen, Elie Roux and Manuel Pegourie-Gonnard", copyright = "Hans Hagen, Elie Roux and Manuel Pegourie-Gonnard", license = "CC0", }) local callbacklist = callbacklist or { } local list, data, first, simple = 1, 2, 3, 4 local types = { list = list, data = data, first = first, simple = simple, } local callbacktypes = callbacktypes or { find_read_file = first, find_write_file = first, find_font_file = data, find_output_file = data, find_format_file = data, find_vf_file = data, find_ocp_file = data, find_map_file = data, find_enc_file = data, find_sfd_file = data, find_pk_file = data, find_data_file = data, find_opentype_file = data, find_truetype_file = data, find_type1_file = data, find_image_file = data, open_read_file = first, read_font_file = first, read_vf_file = first, read_ocp_file = first, read_map_file = first, read_enc_file = first, read_sfd_file = first, read_pk_file = first, read_data_file = first, read_truetype_file = first, read_type1_file = first, read_opentype_file = first, process_input_buffer = data, process_output_buffer = data, token_filter = first, buildpage_filter = simple, pre_linebreak_filter = list, linebreak_filter = list, post_linebreak_filter = list, hpack_filter = list, vpack_filter = list, pre_output_filter = list, hyphenate = simple, ligaturing = simple, kerning = simple, mlist_to_hlist = list, start_run = simple, stop_run = simple, start_page_number = simple, stop_page_number = simple, show_error_hook = simple, define_font = first, } local lua_callbacks_defaults = { } local original_register = original_register or callback.register callback.register = function () err("function callback.register has been trapped,\n" .."please use luatexbase.add_to_callback instead.") end local function register_callback(...) return assert(original_register(...)) end local function listhandler (name) return function(head,...) local ret local alltrue = true for _, f in ipairs(callbacklist[name]) do ret = f.func(head, ...) if ret == false then warn("function '%s' returned false\nin callback '%s'", f.description, name) break end if ret ~= true then alltrue = false head = ret end end return alltrue and true or head end end local function datahandler (name) return function(data, ...) for _, f in ipairs(callbacklist[name]) do data = f.func(data, ...) end return data end end local function firsthandler (name) return function(...) return callbacklist[name][1].func(...) end end local function simplehandler (name) return function(...) for _, f in ipairs(callbacklist[name]) do f.func(...) end end end local handlers = { [list] = listhandler, [data] = datahandler, [first] = firsthandler, [simple] = simplehandler, } function add_to_callback (name,func,description,priority) if type(func) ~= "function" then return err("unable to add function:\nno proper function passed") end if not name or name == "" then err("unable to add function:\nno proper callback name passed") return elseif not callbacktypes[name] then err("unable to add function:\n'%s' is not a valid callback", name) return end if not description or description == "" then err("unable to add function to '%s':\nno proper description passed", name) return end if priority_in_callback(name, description) then err("function '%s' already registered\nin callback '%s'", description, name) return end local l = callbacklist[name] if not l then l = {} callbacklist[name] = l if not lua_callbacks_defaults[name] then register_callback(name, handlers[callbacktypes[name]](name)) end end local f = { func = func, description = description, } priority = tonumber(priority) if not priority or priority > #l then priority = #l+1 elseif priority < 1 then priority = 1 end table.insert(l,priority,f) if callbacktypes[name] == first and #l ~= 1 then warning("several functions in '%s',\n" .."only one will be active.", name) end info("inserting '%s'\nat position %s in '%s'", description, priority, name) end function remove_from_callback (name, description) if not name or name == "" then err("unable to remove function:\nno proper callback name passed") return elseif not callbacktypes[name] then err("unable to remove function:\n'%s' is not a valid callback", name) return end if not description or description == "" then err( "unable to remove function from '%s':\nno proper description passed", name) return end local l = callbacklist[name] if not l then err("no callback list for '%s'",name) return end local index = false for k,v in ipairs(l) do if v.description == description then index = k break end end if not index then err("unable to remove '%s'\nfrom '%s'", description, name) return end table.remove(l, index) info("removing '%s'\nfrom '%s'", description, name) if table.maxn(l) == 0 then callbacklist[name] = nil if not lua_callbacks_defaults[name] then register_callback(name, nil) end end return end function reset_callback (name, make_false) if not name or name == "" then err("unable to reset:\nno proper callback name passed") return elseif not callbacktypes[name] then err("unable to reset '%s':\nis not a valid callback", name) return end info("resetting callback '%s'", name) callbacklist[name] = nil if not lua_callbacks_defaults[name] then if make_false == true then info("setting '%s' to false", name) register_callback(name, false) else register_callback(name, nil) end end end function priority_in_callback (name, description) if not name or name == "" or not callbacktypes[name] or not description then return false end local l = callbacklist[name] if not l then return false end for p, f in pairs(l) do if f.description == description then return p end end return false end function create_callback(name, ctype, default) if not name then err("unable to call callback:\nno proper name passed", name) return nil end if not ctype or not default then err("unable to create callback '%s':\n" .."callbacktype or default function not specified", name) return nil end if callbacktypes[name] then err("unable to create callback '%s':\ncallback already exists", name) return nil end ctype = types[ctype] if not ctype then err("unable to create callback '%s':\ntype '%s' undefined", name, ctype) return nil end info("creating '%s' type %s", name, ctype) lua_callbacks_defaults[name] = default callbacktypes[name] = ctype end function call_callback(name, ...) if not name then err("unable to call callback:\nno proper name passed", name) return nil end if not lua_callbacks_defaults[name] then err("unable to call lua callback '%s':\nunknown callback", name) return nil end local l = callbacklist[name] local f if not l then f = lua_callbacks_defaults[name] else f = handlers[callbacktypes[name]](name) if not f then err("unknown callback type") return end end return f(...) end -- -- End of File `mcb.lua'.