diff options
Diffstat (limited to 'luatexbase-attr.dtx')
| -rw-r--r-- | luatexbase-attr.dtx | 251 |
1 files changed, 232 insertions, 19 deletions
diff --git a/luatexbase-attr.dtx b/luatexbase-attr.dtx index ded08b3..60ca026 100644 --- a/luatexbase-attr.dtx +++ b/luatexbase-attr.dtx @@ -116,7 +116,7 @@ See the aforementioned source file(s) for copyright and licensing information. % \begin{abstract} % In addition to the registers existing in \tex and \etex, \luatex introduces % a new concept: attributes. This package takes care of attribute allocation -% just like Plain TeX and LaTeX do for other registers, and also provides a +% just like Plain \tex and \latex do for other registers, and also provides a % Lua interface. % \end{abstract} % @@ -283,7 +283,7 @@ See the aforementioned source file(s) for copyright and licensing information. % \subsubsection{Load supporting Lua module} % % First load \pk{luatexbase-loader} (hence \pk{luatexbase-compat}), then -% the supporting Lua module. We make sure luatex.sty is loaded. +% the supporting Lua module. We make sure \verb|luatex.sty| is loaded. % % \begin{macrocode} \begingroup\expandafter\expandafter\expandafter\endgroup @@ -299,7 +299,7 @@ See the aforementioned source file(s) for copyright and licensing information. % % \subsection{User macros} % -% The allocaton macro is merely a wrapper around the Lua function, but +% The allocation macro is merely a wrapper around the Lua function, but % handles error and logging in \tex, for consistency with other allocation % macros. % @@ -344,22 +344,62 @@ See the aforementioned source file(s) for copyright and licensing information. % % \begin{macrocode} %<*luamodule> -module('luatexbase', package.seeall) +--- locals +local nodenew = node.new +local nodesubtype = node.subtype +local nodetype = node.id +local stringfind = string.find +local stringformat = string.format +local tableunpack = unpack or table.unpack +local texiowrite_nl = texio.write_nl +local texiowrite = texio.write +--- luatex internal types +local whatsit_t = nodetype"whatsit" +local user_defined_t = nodesubtype"user_defined" +local unassociated = "__unassociated" +luatexbase = luatexbase or { } +local luatexbase = luatexbase +% \end{macrocode} +% +% We improvise a basic logging facility. +% +% \begin{macrocode} +local reporter = function (log, category, ...) + if log == true then + texiowrite_nl("log", "("..category..") ") + texiowrite("log", stringformat(...)) + else + texiowrite_nl("("..category..") ") + texiowrite(stringformat(...)) + end +end +local warning = function (...) reporter (false, "warning", ...) end +----- info = function (...) reporter (false, "info", ...) end +local log = function (...) reporter (true, "log", ...) end % \end{macrocode} % % This table holds the values of the allocated attributes, indexed by name. % % \begin{macrocode} -attributes = {} +luatexbase.attributes = luatexbase.attributes or { } +local attributes = luatexbase.attributes % \end{macrocode} % -% There are currently two functions that create a new attribute.One is in -% |oberdiek| bundle, the other is this one. We will hack a little in order -% to make them compatible. The other function uses |LuT@AllocAttribute| as -% attribute counter, we will keep it in sync with ours. A possible problem -% might also appear: the other function starts attribute allocation at 0, -% which might break luaotfload. We output an error if a new attribute has -% already been allocated with number 0. +% Scoping: we use locals for the attribute functions. +% +% \begin{macrocode} +local new_attribute +local unset_attribute +% \end{macrocode} +% +% In the \luatex ecosystem there are currently two functions that create a +% new attribute. +% One is in |oberdiek| bundle, the other is this one. We will hack a little +% in order to make them compatible. The other function uses +% |LuT@AllocAttribute| as attribute counter, we will keep it in sync with +% ours. A possible problem might also appear: the other function starts +% attribute allocation at 0, which will break luaotfload. We output an +% error if a new attribute has already been allocated with number 0. % % \begin{macrocode} local luatex_sty_counter = 'LuT@AllocAttribute' @@ -367,17 +407,17 @@ if tex.count[luatex_sty_counter] then if tex.count[luatex_sty_counter] > -1 then error("luatexbase error: attribute 0 has already been set by \newattribute" .."macro from luatex.sty, not belonging to this package, this makes" - .."luaotfload unuseable. Please report to the maintainer of luatex.sty") + .."luaotfload unusable. Please report to the maintainer of luatex.sty") else tex.count[luatex_sty_counter] = 0 end end % \end{macrocode} % -% The allocaton function. Unlike other registers, allocate starting from 1. -% Some code (eg, font handling coming from Con\tex{}t) behaves strangely -% with \verb+\attribute0+ and since there is plenty of room here, it -% doesn't seem bad to ``loose'' one item in order to avoid this problem. +% The allocation function. Unlike other registers, allocate starting from 1. +% Some code (e.~g., font handling coming from Con\tex{}t) behaves strangely +% with \verb+\attribute0+ set, and since there is plenty of room here, it +% doesn't seem bad to ``lose'' one item in order to avoid this problem. % % \begin{macrocode} local last_alloc = 0 @@ -400,11 +440,11 @@ function new_attribute(name, silent) attributes[name] = last_alloc unset_attribute(name) if not silent then - texio.write_nl('log', string.format( - 'luatexbase.attributes[%q] = %d', name, last_alloc)) + log('luatexbase.attributes[%q] = %d', name, last_alloc) end return last_alloc end +luatexbase.new_attribute = new_attribute % \end{macrocode} % % Unset an attribute the correct way depending on \luatex's version. @@ -414,6 +454,179 @@ local unset_value = (luatexbase.luatexversion < 37) and -1 or -2147483647 function unset_attribute(name) tex.setattribute(attributes[name], unset_value) end +luatexbase.unset_attribute = unset_attribute +% \end{macrocode} +% +% User whatsit allocation (experimental). +% +% \begin{macrocode} +--- cf. luatexref-t.pdf, sect. 8.1.4.25 +local user_whatsits = { --- (package, (name, id hash)) hash + __unassociated = { }, --- those without package name +} +local whatsit_ids = { } --- (id, (name * package)) hash +local whatsit_cap = 2^53 --- Lua numbers are doubles +local current_whatsit = 0 +local anonymous_whatsits = 0 +local anonymous_prefix = "anon" +% \end{macrocode} +% +% The whatsit allocation is split into two functions: +% \verb|new_user_whatsit_id| registers a new id (an integer) +% and returns it. It is up to the user what he actually does +% with the return value. +% +% Registering whatsits without a name, though supported, is +% not exactly good style. In these cases we generate a name +% from a counter. +% +% In addition to the whatsit name, it is possible and even +% encouraged to specify the name of the package that will be +% using the whatsit as the second argument. +% +% \begin{macrocode} +--- string -> string -> int +local new_user_whatsit_id = function (name, package) + if name then + if not package then + package = unassociated + end + else -- anonymous + anonymous_whatsits = anonymous_whatsits + 1 + warning("defining anonymous user whatsit no. %d", anonymous_whatsits) + warning("dear package authors, please name your whatsits!") + package = unassociated + name = anonymous_prefix .. tostring(anonymous_whatsits) + end + + local whatsitdata = user_whatsits[package] + if not whatsitdata then + whatsitdata = { } + user_whatsits[package] = whatsitdata + end + + local id = whatsitdata[name] + if id then --- warning + warning("replacing whatsit %s:%s (%d)", package, name, id) + else --- new id + current_whatsit = current_whatsit + 1 + if current_whatsit >= whatsit_cap then + warning("maximum of %d integral user whatsit ids reached", + whatsit_cap) + warning("further whatsit allocation may be inconsistent") + end + id = current_whatsit + whatsitdata[name] = id + whatsit_ids[id] = { name, package } + end + log("new user-defined whatsit %d (%s:%s)", id, package, name) + return id +end +luatexbase.new_user_whatsit_id = new_user_whatsit_id +% \end{macrocode} +% +% \verb|new_user_whatsit| first registers a new id and +% then also creates the corresponding whatsit of subtype “user defined”. +% Return values are said node and its id. +% +% \begin{macrocode} +--- string -> string -> (node_t -> int) +local new_user_whatsit = function (name, package) + local id = new_user_whatsit_id(name, package) + local wi = nodenew(whatsit_t, user_defined_t) + wi.user_id = id + return wi, id +end +luatexbase.new_user_whatsit = new_user_whatsit +% \end{macrocode} +% +% If one knows the name of a whatsit, its corresponding id +% can be retrieved by means of \verb|get_user_whatsit_id|. +% +% \begin{macrocode} +--- string -> string -> int +local get_user_whatsit_id = function (name, package) + if not package then + package = unassociated + end + return user_whatsits[package][name] +end +luatexbase.get_user_whatsit_id = get_user_whatsit_id +% \end{macrocode} +% +% The inverse lookup is also possible via \verb|get_user_whatsit_name|. +% Here it finally becomes obvious why it is beneficial to supply a package +% name -- it adds information about who created and might be relying on the +% whatsit in question. First return value is the whatsit name, the second +% the package identifier it was registered with. +% +% We issue a warning and return empty strings in case the asked whatsit is +% unregistered. +% +% \begin{macrocode} +--- int | node -> (string, string) +local get_user_whatsit_name = function (asked) + local id + if type(asked) == "number" then + id = asked + else --- node + id = asked.user_id + end + local metadata = whatsit_ids[id] + if not metadata then -- unknown + warning("whatsit id %d unregistered; inconsistencies may arise", id) + return "", "" + end + return tableunpack(metadata) +end +luatexbase.get_user_whatsit_name = get_user_whatsit_name +% \end{macrocode} +% +% For the curious as well as the cautious who are interesting in +% what they are dealing with, we add a function that outputs the +% current allocation status to the terminal. +% +% \begin{macrocode} +--- string -> unit +local dump_registered_whatsits = function (asked_package) + local whatsit_list = { } + if asked_package then + local whatsitdata = user_whatsits[asked_package] + if not whatsitdata then + error("(no user whatsits registered for package %s)", + asked_package) + return + end + texiowrite_nl("(user whatsit allocation stats for " .. asked_package) + for name, id in next, whatsitdata do + whatsit_list[#whatsit_list+1] = + stringformat("(%s:%s %d)", asked_package, name, id) + end + else + texiowrite_nl("(user whatsit allocation stats") + texiowrite_nl(stringformat(" ((total %d)\n (anonymous %d))", + current_whatsit, anonymous_whatsits)) + for package, whatsitdata in next, user_whatsits do + for name, id in next, whatsitdata do + whatsit_list[#whatsit_list+1] = + stringformat("(%s:%s %d)", package, name, id) + end + end + end + texiowrite_nl" (" + texiowrite(table.concat(whatsit_list, "\n ")) + texiowrite"))" +end +luatexbase.dump_registered_whatsits = dump_registered_whatsits +% \end{macrocode} +% Lastly, we define a couple synonyms for convenience. +% \begin{macrocode} +luatexbase.newattribute = new_attribute +luatexbase.newuserwhatsit = new_user_whatsit +luatexbase.newuserwhatsitid = new_user_whatsit_id +luatexbase.getuserwhatsitid = get_user_whatsit_id +luatexbase.getuserwhatsitname = get_user_whatsit_name +luatexbase.dumpregisteredwhatsits = dump_registered_whatsits % \end{macrocode} % % \begin{macrocode} |