[main,gitignore] add self-contained luaotfload.lua

1 files changed, 700 insertions, 0 deletions

diff --git a/luaotfload.lua b/luaotfload.lua
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+++ b/luaotfload.lua
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+-----------------------------------------------------------------------
+--         FILE:  luaotfload.lua
+--  DESCRIPTION:  Luatex fontloader initialization
+-- REQUIREMENTS:  luatex v.0.78 or later, the lualibs package
+--       AUTHOR:  Élie Roux, Khaled Hosny, Philipp Gesang
+--      VERSION:  same as Luaotfload
+--     MODIFIED:  2014-01-16 06:51:20+0100
+-----------------------------------------------------------------------
+--
+--- Note:
+--- This file was part of the original luaotfload.dtx and has been
+--- converted to a pure Lua file during the transition from Luaotfload
+--- version 2.4 to 2.5. Thus, the comments are still in TeX (Latex)
+--- markup.
+
+if not modules then modules = { } end modules ["luaotfload"] = {
+    version   = "2.5",
+    comment   = "fontloader initialization",
+    author    = "Hans Hagen, Khaled Hosny, Elie Roux, Philipp Gesang",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "GNU General Public License v. 2.0"
+}
+
+
+--[[doc--
+
+    This file initializes the system and loads the font loader. To
+    minimize potential conflicts between other packages and the code
+    imported from \CONTEXT, several precautions are in order. Some of
+    the functionality that the font loader expects to be present, like
+    raw access to callbacks, are assumed to have been disabled by
+    \identifier{luatexbase} when this file is processed. In some cases
+    it is possible to trick it by putting dummies into place and
+    restoring the behavior from \identifier{luatexbase} after
+    initilization. Other cases such as attribute allocation require
+    that we hook the functionality from \identifier{luatexbase} into
+    locations where they normally wouldn’t be.
+
+    Anyways we can import the code base without modifications, which is
+    due mostly to the extra effort by Hans Hagen to make \LUATEX-Fonts
+    self-contained and encapsulate it, and especially due to his
+    willingness to incorporate our suggestions.
+
+--doc]]--
+
+luaotfload                        = luaotfload or { }
+local luaotfload                  = luaotfload
+
+config                            = config or { }
+config.luaotfload                 = config.luaotfload or { }
+------.luaotfload.resolver        = config.luaotfload.resolver         or "normal"
+config.luaotfload.resolver        = config.luaotfload.resolver         or "cached"
+config.luaotfload.definer         = config.luaotfload.definer          or "patch"
+config.luaotfload.loglevel        = config.luaotfload.loglevel         or 2
+config.luaotfload.color_callback  = config.luaotfload.color_callback   or "pre_linebreak_filter"
+config.luaotfload.prioritize      = config.luaotfload.prioritize       or "sys"
+config.luaotfload.names_dir       = config.luaotfload.names_dir        or "names"
+config.luaotfload.cache_dir       = config.luaotfload.cache_dir        or "fonts"
+config.luaotfload.index_file      = config.luaotfload.index_file       or "luaotfload-names.lua"
+config.luaotfload.formats         = config.luaotfload.formats          or "otf,ttf,ttc,dfont"
+
+if not config.luaotfload.strip then
+    config.luaotfload.strip = true
+end
+
+luaotfload.module = {
+    name          = "luaotfload",
+    version       = 2.50000,
+    date          = "2014/**/**",
+    description   = "OpenType layout system.",
+    author        = "Elie Roux & Hans Hagen",
+    copyright     = "Elie Roux",
+    license       = "GPL v2.0"
+}
+
+local luatexbase       = luatexbase
+
+local setmetatable     = setmetatable
+local type, next       = type, next
+
+local kpsefind_file    = kpse.find_file
+local lfsisfile        = lfs.isfile
+
+local add_to_callback, create_callback =
+      luatexbase.add_to_callback, luatexbase.create_callback
+local reset_callback, call_callback =
+      luatexbase.reset_callback, luatexbase.call_callback
+
+local dummy_function = function () end
+
+local error, warning, info, log =
+    luatexbase.provides_module(luaotfload.module)
+
+luaotfload.error        = error
+luaotfload.warning      = warning
+luaotfload.info         = info
+luaotfload.log          = log
+
+--[[doc--
+
+     We set the minimum version requirement for \LUATEX to v0.76,
+     because the font loader requires recent features like direct
+     attribute indexing and \luafunction{node.end_of_math()} that aren’t
+     available in earlier versions.\footnote{%
+      See Taco’s announcement of v0.76:
+      \url{http://comments.gmane.org/gmane.comp.tex.luatex.user/4042}
+      and this commit by Hans that introduced those features.
+      \url{http://repo.or.cz/w/context.git/commitdiff/a51f6cf6ee087046a2ae5927ed4edff0a1acec1b}.
+    }
+
+--doc]]--
+
+local luatex_version = 76
+
+if tex.luatexversion < luatex_version then
+    warning("LuaTeX v%.2f is old, v%.2f is recommended.",
+             tex.luatexversion/100,
+             luatex_version   /100)
+    --- we install a fallback for older versions as a safety
+    if not node.end_of_math then
+        local math_t          = node.id"math"
+        local traverse_nodes  = node.traverse_id
+        node.end_of_math = function (n)
+            for n in traverse_nodes(math_t, n.next) do
+                return n
+            end
+        end
+    end
+end
+
+--[[doc--
+
+    \subsection{Module loading}
+    We load the files imported from \CONTEXT with this function. It
+    automatically prepends the prefix \fileent{luaotfload-} to its
+    argument, so we can refer to the files with their actual \CONTEXT
+    name.
+
+--doc]]--
+
+local fl_prefix = "luaotfload" -- “luatex” for luatex-plain
+local loadmodule = function (name)
+    require(fl_prefix .."-"..name)
+end
+
+--[[doc--
+
+  Before \TeX Live 2013 version, \LUATEX had a bug that made ofm fonts
+  fail when called with their extension. There was a side-effect making
+  ofm totally unloadable when luaotfload was present. The following
+  lines are a patch for this bug. The utility of these lines is
+  questionable as they are not necessary since \TeX Live 2013. They
+  should be removed in the next version.
+
+--doc]]--
+
+
+local p_dot, p_slash = P".",  P"/"
+local p_suffix       = (p_dot * (1 - p_dot - p_slash)^1 * P(-1)) / ""
+local p_removesuffix = Cs((p_suffix + 1)^1)
+
+local find_vf_file = function (name)
+    local fullname = kpsefind_file(name, "ovf")
+    if not fullname then
+        --fullname = kpsefind_file(file.removesuffix(name), "ovf")
+        fullname = kpsefind_file(lpegmatch(p_removesuffix, name), "ovf")
+    end
+    if fullname then
+        log("loading virtual font file %s.", fullname)
+    end
+    return fullname
+end
+
+--[[doc--
+
+    \subsection{Preparing the Font Loader}
+    We treat the fontloader as a black box so behavior is consistent
+    between formats.
+    We load the fontloader code directly in the same fashion as the
+    Plain format \identifier{luatex-fonts} that is part of Context.
+    How this is executed depends on the presence on the
+    \emphasis{merged font loader code}.
+    In \identifier{luaotfload} this is contained in the file
+    \fileent{luaotfload-merged.lua}.
+    If this file cannot be found, the original libraries from \CONTEXT
+    of which the merged code was composed are loaded instead.
+    Since these files are not shipped with Luaotfload, an installation
+    of Context is required.
+    (Since we pull the fontloader directly from the Context minimals,
+    the necessary Context version is likely to be more recent than that
+    of other TeX distributions like Texlive.)
+    The imported font loader will call \luafunction{callback.register}
+    once while reading \fileent{font-def.lua}.
+    This is unavoidable unless we modify the imported files, but
+    harmless if we make it call a dummy instead.
+    However, this problem might vanish if we decide to do the merging
+    ourselves, like the \identifier{lualibs} package does.
+    With this step we would obtain the freedom to load our own
+    overrides in the process right where they are needed, at the cost
+    of losing encapsulation.
+    The decision on how to progress is currently on indefinite hold.
+
+--doc]]--
+
+local starttime = os.gettimeofday()
+
+local trapped_register  = callback.register
+callback.register       = dummy_function
+
+--[[doc--
+
+    By default, the fontloader requires a number of \emphasis{private
+    attributes} for internal use.
+    These must be kept consistent with the attribute handling methods
+    as provided by \identifier{luatexbase}.
+    Our strategy is to override the function that allocates new
+    attributes before we initialize the font loader, making it a
+    wrapper around \luafunction{luatexbase.new_attribute}.\footnote{%
+        Many thanks, again, to Hans Hagen for making this part
+        configurable!
+    }
+    The attribute identifiers are prefixed “\fileent{luaotfload@}” to
+    avoid name clashes.
+
+--doc]]--
+
+do
+    local new_attribute    = luatexbase.new_attribute
+    local the_attributes   = luatexbase.attributes
+
+    attributes = attributes or { }
+
+    attributes.private = function (name)
+        local attr   = "luaotfload@" .. name --- used to be: “otfl@”
+        local number = the_attributes[attr]
+        if not number then
+            number = new_attribute(attr)
+        end
+        return number
+    end
+end
+
+--[[doc--
+
+    These next lines replicate the behavior of
+    \fileent{luatex-fonts.lua}.
+
+--doc]]--
+
+local context_environment = { }
+
+local push_namespaces = function ()
+    log("push namespace for font loader")
+    local normalglobal = { }
+    for k, v in next, _G do
+        normalglobal[k] = v
+    end
+    return normalglobal
+end
+
+local pop_namespaces = function (normalglobal, isolate)
+    if normalglobal then
+        local _G = _G
+        local mode = "non-destructive"
+        if isolate then mode = "destructive" end
+        log("pop namespace from font loader -- " .. mode)
+        for k, v in next, _G do
+            if not normalglobal[k] then
+                context_environment[k] = v
+                if isolate then
+                    _G[k] = nil
+                end
+            end
+        end
+        for k, v in next, normalglobal do
+            _G[k] = v
+        end
+        -- just to be sure:
+        setmetatable(context_environment,_G)
+    else
+        log("irrecoverable error during pop_namespace: no globals to restore")
+        os.exit()
+    end
+end
+
+luaotfload.context_environment  = context_environment
+luaotfload.push_namespaces      = push_namespaces
+luaotfload.pop_namespaces       = pop_namespaces
+
+local our_environment = push_namespaces()
+
+--[[doc--
+
+    The font loader requires that the attribute with index zero be
+    zero. We happily oblige.
+    (Cf. \fileent{luatex-fonts-nod.lua}.)
+
+--doc]]--
+
+tex.attribute[0] = 0
+
+--[[doc--
+
+    Now that things are sorted out we can finally load the fontloader.
+
+--doc]]--
+
+loadmodule "fontloader.lua"
+---loadmodule"font-odv.lua" --- <= Devanagari support from Context
+
+if fonts then
+
+    if not fonts._merge_loaded_message_done_ then
+        log [["I am using the merged version of 'luaotfload.lua' here.]]
+        log [[ If you run into problems or experience unexpected]]
+        log [[ behaviour, and if you have ConTeXt installed you can try]]
+        log [[ to delete the file 'luaotfload-merged.lua' as I might]]
+        log [[ then use the possibly updated libraries. The merged]]
+        log [[ version is not supported as it is a frozen instance.]]
+        log [[ Problems can be reported to the ConTeXt mailing list."]]
+    end
+    fonts._merge_loaded_message_done_ = true
+
+else--- the loading sequence is known to change, so this might have to
+    --- be updated with future updates!
+    --- do not modify it though unless there is a change to the merged
+    --- package!
+    loadmodule("l-lua.lua")
+    loadmodule("l-lpeg.lua")
+    loadmodule("l-function.lua")
+    loadmodule("l-string.lua")
+    loadmodule("l-table.lua")
+    loadmodule("l-io.lua")
+    loadmodule("l-file.lua")
+    loadmodule("l-boolean.lua")
+    loadmodule("l-math.lua")
+    loadmodule("util-str.lua")
+    loadmodule('luatex-basics-gen.lua')
+    loadmodule('data-con.lua')
+    loadmodule('luatex-basics-nod.lua')
+    loadmodule('font-ini.lua')
+    loadmodule('font-con.lua')
+    loadmodule('luatex-fonts-enc.lua')
+    loadmodule('font-cid.lua')
+    loadmodule('font-map.lua')
+    loadmodule('luatex-fonts-syn.lua')
+    loadmodule('luatex-fonts-tfm.lua')
+    loadmodule('font-oti.lua')
+    loadmodule('font-otf.lua')
+    loadmodule('font-otb.lua')
+    loadmodule('luatex-fonts-inj.lua')  --> since 2014-01-07, replaces node-inj.lua
+    loadmodule('font-ota.lua')
+    loadmodule('luatex-fonts-otn.lua')  --> since 2014-01-07, replaces font-otn.lua
+    loadmodule('font-otp.lua')          --> since 2013-04-23
+    loadmodule('luatex-fonts-lua.lua')
+    loadmodule('font-def.lua')
+    loadmodule('luatex-fonts-def.lua')
+    loadmodule('luatex-fonts-ext.lua')
+    loadmodule('luatex-fonts-cbk.lua')
+end --- non-merge fallback scope
+
+--[[doc--
+
+    Here we adjust the globals created during font loader
+    initialization. If the second argument to
+    \luafunction{pop_namespaces()} is \verb|true| this will restore the
+    state of \luafunction{_G}, eliminating every global generated since
+    the last call to \luafunction{push_namespaces()}. At the moment we
+    see no reason to do this, and since the font loader is considered
+    an essential part of \identifier{luatex} as well as a very well
+    organized piece of code, we happily concede it the right to add to
+    \luafunction{_G} if needed.
+
+--doc]]--
+
+pop_namespaces(our_environment, false)-- true)
+
+log("fontloader loaded in %0.3f seconds", os.gettimeofday()-starttime)
+
+--[[doc--
+
+    \subsection{Callbacks}
+    After the fontloader is ready we can restore the callback trap from
+    \identifier{luatexbase}.
+
+--doc]]--
+
+callback.register = trapped_register
+
+--[[doc--
+
+    We do our own callback handling with the means provided by
+    luatexbase.
+    Note: \luafunction{pre_linebreak_filter} and
+    \luafunction{hpack_filter} are coupled in \CONTEXT in the concept
+    of \emphasis{node processor}.
+
+--doc]]--
+
+add_to_callback("pre_linebreak_filter",
+                nodes.simple_font_handler,
+                "luaotfload.node_processor",
+                1)
+add_to_callback("hpack_filter",
+                nodes.simple_font_handler,
+                "luaotfload.node_processor",
+                1)
+add_to_callback("find_vf_file",
+                find_vf_file, "luaotfload.find_vf_file")
+
+loadmodule "override.lua"   --- “luat-ovr”
+
+logs.set_loglevel(config.luaotfload.loglevel)
+
+--[[doc--
+
+    Now we load the modules written for \identifier{luaotfload}.
+
+--doc]]--
+loadmodule "parsers.lua"    --- new in 2.5; fonts.conf and syntax
+loadmodule "loaders.lua"    --- “font-pfb” new in 2.0, added 2011
+loadmodule "database.lua"   --- “font-nms”
+loadmodule "colors.lua"     --- “font-clr”
+
+--[[doc--
+
+    Relying on the \verb|name:| resolver for everything has been the
+    source of permanent trouble with the database.
+    With the introduction of the new syntax parser we now have enough
+    granularity to distinguish between the \XETEX emulation layer and
+    the genuine \verb|name:| and \verb|file:| lookups of \LUATEX-Fonts.
+    Another benefit is that we can now easily plug in or replace new
+    lookup behaviors if necessary.
+    The name resolver remains untouched, but it calls
+    \luafunction{fonts.names.resolve()} internally anyways (see
+    \fileent{luaotfload-database.lua}).
+
+--doc]]--
+
+local filesuffix          = file.suffix
+local fileremovesuffix    = file.removesuffix
+local request_resolvers   = fonts.definers.resolvers
+local formats             = fonts.formats
+local names               = fonts.names
+formats.ofm               = "type1"
+
+fonts.encodings.known     = fonts.encodings.known or { }
+
+--[[doc--
+
+    \identifier{luaotfload} promises easy access to system fonts.
+    Without additional precautions, this cannot be achieved by
+    \identifier{kpathsea} alone, because it searches only the
+    \fileent{texmf} directories by default.
+    Although it is possible for \identifier{kpathsea} to include extra
+    paths by adding them to the \verb|OSFONTDIR| environment variable,
+    this is still short of the goal »\emphasis{it just works!}«.
+    When building the font database \identifier{luaotfload} scans
+    system font directories anyways, so we already have all the
+    information for looking sytem fonts.
+    With the release version 2.2 the file names are indexed in the
+    database as well and we are ready to resolve \verb|file:| lookups
+    this way.
+    Thus we no longer need to call the \identifier{kpathsea} library in
+    most cases when looking up font files, only when generating the
+    database, and when verifying the existence of a file in the
+    \fileent{texmf} tree.
+
+--doc]]--
+
+local resolve_file        = names.crude_file_lookup
+--local resolve_file        = names.crude_file_lookup_verbose
+local resolve_name        = names.resolve_name
+
+local file_resolver = function (specification)
+    local name    = resolve_file (specification.name)
+    local suffix  = filesuffix(name)
+    if formats[suffix] then
+        specification.forced      = suffix
+        specification.forcedname  = file.removesuffix(name)
+    else
+        specification.name = name
+    end
+end
+
+request_resolvers.file = file_resolver
+
+--[[doc--
+
+    We classify as \verb|anon:| those requests that have neither a
+    prefix nor brackets. According to Khaled\footnote{%
+        \url{https://github.com/phi-gamma/luaotfload/issues/4#issuecomment-17090553}.
+    }
+    they are the \XETEX equivalent of a \verb|name:| request, so we
+    will be treating them as such.
+
+--doc]]--
+
+--request_resolvers.anon = request_resolvers.name
+
+--[[doc--
+
+    There is one drawback, though.
+    This syntax is also used for requesting fonts in \identifier{Type1}
+    (\abbrev{tfm}, \abbrev{ofm}) format.
+    These are essentially \verb|file:| lookups and must be caught
+    before the \verb|name:| resolver kicks in, lest they cause the
+    database to update.
+    Even if we were to require the \verb|file:| prefix for all
+    \identifier{Type1} requests, tests have shown that certain fonts
+    still include further fonts (e.~g. \fileent{omlgcb.ofm} will ask
+    for \fileent{omsecob.tfm}) \emphasis{using the old syntax}.
+    For this reason, we introduce an extra check with an early return.
+
+--doc]]--
+
+local type1_formats = { "tfm", "ofm", }
+
+request_resolvers.anon = function (specification)
+    local name = specification.name
+    for i=1, #type1_formats do
+        local format = type1_formats[i]
+        if resolvers.findfile(name, format) then
+            specification.forcedname = file.addsuffix(name, format)
+            specification.forced     = format
+            return
+        end
+    end
+    --- under some weird circumstances absolute paths get
+    --- passed to the definer; we have to catch them
+    --- before the name: resolver misinterprets them.
+    name = specification.specification
+    local exists, _ = lfsisfile(name)
+    if exists then --- garbage; we do this because we are nice,
+                   --- not because it is correct
+        logs.names_report("log", 1, "load", "file %q exists", name)
+        logs.names_report("log", 1, "load",
+          "... overriding borked anon: lookup with path: lookup")
+        specification.name = name
+        request_resolvers.path(specification)
+        return
+    end
+    request_resolvers.name(specification)
+end
+
+--[[doc--
+
+    Prior to version 2.2, \identifier{luaotfload} did not distinguish
+    \verb|file:| and \verb|path:| lookups, causing complications with
+    the resolver.
+    Now we test if the requested name is an absolute path in the file
+    system, otherwise we fall back to the \verb|file:| lookup.
+
+--doc]]--
+
+request_resolvers.path = function (specification)
+    local name       = specification.name
+    local exists, _  = lfsisfile(name)
+    if not exists then -- resort to file: lookup
+        logs.names_report("log", 1, "load",
+          "path lookup of %q unsuccessful, falling back to file:",
+          name)
+        file_resolver (specification)
+    else
+        local suffix = filesuffix (name)
+        if formats[suffix] then
+            specification.forced      = suffix
+            specification.name        = file.removesuffix(name)
+            specification.forcedname  = name
+        else
+            specification.name = name
+        end
+    end
+end
+
+--[[doc--
+
+    {\bfseries EXPERIMENTAL}:
+    \identifier{kpse}-only resolver, for those who can do without
+    system fonts.
+
+--doc]]--
+
+request_resolvers.kpse = function (specification)
+    local name       = specification.name
+    local suffix     = filesuffix(name)
+    if suffix and formats[suffix] then
+        name = file.removesuffix(name)
+        if resolvers.findfile(name, suffix) then
+            specification.forced       = suffix
+            specification.forcedname   = name
+            return
+        end
+    end
+    for t, format in next, formats do --- brute force
+        if kpse.find_file (name, format) then
+            specification.forced = t
+            specification.name   = name
+            return
+        end
+    end
+end
+
+--[[doc--
+
+    The \verb|name:| resolver wraps the database function
+    \luafunction{resolve_name}.
+
+--doc]]--
+
+--- fonts.names.resolvers.name -- Customized version of the
+--- generic name resolver.
+
+request_resolvers.name = function (specification)
+    local resolved, subfont = resolve_name (specification)
+    if resolved then
+        specification.resolved   = resolved
+        specification.sub        = subfont
+        specification.forced     = filesuffix (resolved)
+        specification.forcedname = resolved
+        specification.name       = fileremovesuffix (resolved)
+    else
+        file_resolver (specification)
+    end
+end
+
+--[[doc--
+
+    Also {\bfseries EXPERIMENTAL}: custom file resolvers via callback.
+
+--doc]]--
+create_callback("luaotfload.resolve_font", "simple", dummy_function)
+
+request_resolvers.my = function (specification)
+    call_callback("luaotfload.resolve_font", specification)
+end
+
+--[[doc--
+
+    We create a callback for patching fonts on the fly, to be used by
+    other packages.
+    It initially contains the empty function that we are going to
+    override below.
+
+--doc]]--
+
+create_callback("luaotfload.patch_font", "simple", dummy_function)
+
+--[[doc--
+
+    \subsection{\CONTEXT override}
+    \label{define-font}
+    We provide a simplified version of the original font definition
+    callback.
+
+--doc]]--
+
+local read_font_file = fonts.definers.read
+
+--- spec -> size -> id -> tmfdata
+local patch_defined_font = function (specification, size, id)
+    local tfmdata = read_font_file(specification, size, id)
+    if type(tfmdata) == "table" and tfmdata.shared then
+        --- We need to test for the “shared” field here
+        --- or else the fontspec capheight callback will
+        --- operate on tfm fonts.
+        call_callback("luaotfload.patch_font", tfmdata, specification)
+    end
+    return tfmdata
+end
+
+reset_callback "define_font"
+
+--[[doc--
+
+    Finally we register the callbacks.
+
+--doc]]--
+
+local font_definer = config.luaotfload.definer
+
+if font_definer == "generic"  then
+  add_to_callback("define_font",
+                  fonts.definers.read,
+                  "luaotfload.define_font",
+                  1)
+elseif font_definer == "patch"  then
+  add_to_callback("define_font",
+                  patch_defined_font,
+                  "luaotfload.define_font",
+                  1)
+end
+
+loadmodule "features.lua"     --- contains what was “font-ltx” and “font-otc”
+loadmodule "letterspace.lua"  --- extra character kerning
+loadmodule "auxiliary.lua"    --- additionaly high-level functionality (new)
+
+luaotfload.aux.start_rewrite_fontname () --- to be migrated to fontspec
+
+-- vim:tw=79:sw=4:ts=4:et