[fontloader] sync with Context as of 2016-08-15

CAVEAT LECTOR This adds font-otc.lua part of which has already been
included in our feature handler.

2 files changed, 954 insertions, 0 deletions

diff --git a/src/fontloader/misc/fontloader-font-otc.lua b/src/fontloader/misc/fontloader-font-otc.lua
new file mode 100644
index 0000000..a553209
--- /dev/null
+++ b/src/fontloader/misc/fontloader-font-otc.lua
@@ -0,0 +1,952 @@
+if not modules then modules = { } end modules ['font-otc'] = {
+    version   = 1.001,
+    comment   = "companion to font-otf.lua (context)",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local format, insert, sortedkeys, tohash = string.format, table.insert, table.sortedkeys, table.tohash
+local type, next = type, next
+local lpegmatch = lpeg.match
+local utfbyte, utflen = utf.byte, utf.len
+
+-- we assume that the other otf stuff is loaded already
+
+local trace_loading       = false  trackers.register("otf.loading", function(v) trace_loading = v end)
+local report_otf          = logs.reporter("fonts","otf loading")
+
+local fonts               = fonts
+local otf                 = fonts.handlers.otf
+local registerotffeature  = otf.features.register
+local setmetatableindex   = table.setmetatableindex
+
+local normalized = {
+    substitution      = "substitution",
+    single            = "substitution",
+    ligature          = "ligature",
+    alternate         = "alternate",
+    multiple          = "multiple",
+    kern              = "kern",
+    pair              = "pair",
+    chainsubstitution = "chainsubstitution",
+    chainposition     = "chainposition",
+}
+
+local types = {
+    substitution      = "gsub_single",
+    ligature          = "gsub_ligature",
+    alternate         = "gsub_alternate",
+    multiple          = "gsub_multiple",
+    kern              = "gpos_pair",
+    pair              = "gpos_pair",
+    chainsubstitution = "gsub_contextchain",
+    chainposition     = "gpos_contextchain",
+}
+
+local names = {
+    gsub_single              = "gsub",
+    gsub_multiple            = "gsub",
+    gsub_alternate           = "gsub",
+    gsub_ligature            = "gsub",
+    gsub_context             = "gsub",
+    gsub_contextchain        = "gsub",
+    gsub_reversecontextchain = "gsub",
+    gpos_single              = "gpos",
+    gpos_pair                = "gpos",
+    gpos_cursive             = "gpos",
+    gpos_mark2base           = "gpos",
+    gpos_mark2ligature       = "gpos",
+    gpos_mark2mark           = "gpos",
+    gpos_context             = "gpos",
+    gpos_contextchain        = "gpos",
+}
+
+setmetatableindex(types, function(t,k) t[k] = k return k end) -- "key"
+
+local everywhere = { ["*"] = { ["*"] = true } } -- or: { ["*"] = { "*" } }
+local noflags    = { false, false, false, false }
+
+-- beware: shared, maybe we should copy the sequence
+
+local function getrange(sequences,category)
+    local count = #sequences
+    local first = nil
+    local last  = nil
+    for i=1,count do
+        local t = sequences[i].type
+        if t and names[t] == category then
+            if not first then
+                first = i
+            end
+            last  = i
+        end
+    end
+    return first or 1, last or count
+end
+
+local function validspecification(specification,name)
+    local dataset = specification.dataset
+    if dataset then
+        -- okay
+    elseif specification[1] then
+        dataset = specification
+        specification = { dataset = dataset }
+    else
+        dataset = { { data = specification.data } }
+        specification.data    = nil
+        specification.dataset = dataset
+    end
+    local first = dataset[1]
+    if first then
+        first = first.data
+    end
+    if not first then
+        report_otf("invalid feature specification, no dataset")
+        return
+    end
+    if type(name) ~= "string" then
+        name = specification.name or first.name
+    end
+    if type(name) ~= "string" then
+        report_otf("invalid feature specification, no name")
+        return
+    end
+    local n = #dataset
+    if n > 0 then
+        for i=1,n do
+            setmetatableindex(dataset[i],specification)
+        end
+        return specification, name
+    end
+end
+
+local function addfeature(data,feature,specifications)
+
+    -- todo: add some validator / check code so that we're more tolerant to
+    -- user errors
+
+    if not specifications then
+        report_otf("missing specification")
+        return
+    end
+
+    local descriptions = data.descriptions
+    local resources    = data.resources
+    local features     = resources.features
+    local sequences    = resources.sequences
+
+    if not features or not sequences then
+        report_otf("missing specification")
+        return
+    end
+
+    local alreadydone = resources.alreadydone
+    if not alreadydone then
+        alreadydone = { }
+        resources.alreadydone = alreadydone
+    end
+    if alreadydone[specifications] then
+        return
+    else
+        alreadydone[specifications] = true
+    end
+
+    -- feature has to be unique but the name entry wins eventually
+
+    local fontfeatures = resources.features or everywhere
+    local unicodes     = resources.unicodes
+    local splitter     = lpeg.splitter(" ",unicodes)
+    local done         = 0
+    local skip         = 0
+    local aglunicodes  = false
+
+    local specifications = validspecification(specifications,feature)
+    if not specifications then
+     -- report_otf("invalid specification")
+        return
+    end
+
+    local function tounicode(code)
+        if not code then
+            return
+        end
+        if type(code) == "number" then
+            return code
+        end
+        local u = unicodes[code]
+        if u then
+            return u
+        end
+        if utflen(code) == 1 then
+            u = utfbyte(code)
+            if u then
+                return u
+            end
+        end
+        if not aglunicodes then
+            aglunicodes = fonts.encodings.agl.unicodes -- delayed
+        end
+        return aglunicodes[code]
+    end
+
+    local coverup      = otf.coverup
+    local coveractions = coverup.actions
+    local stepkey      = coverup.stepkey
+    local register     = coverup.register
+
+    local function prepare_substitution(list,featuretype)
+        local coverage = { }
+        local cover    = coveractions[featuretype]
+        for code, replacement in next, list do
+            local unicode     = tounicode(code)
+            local description = descriptions[unicode]
+            if description then
+                if type(replacement) == "table" then
+                    replacement = replacement[1]
+                end
+                replacement = tounicode(replacement)
+                if replacement and descriptions[replacement] then
+                    cover(coverage,unicode,replacement)
+                    done = done + 1
+                else
+                    skip = skip + 1
+                end
+            else
+                skip = skip + 1
+            end
+        end
+        return coverage
+    end
+
+    local function prepare_alternate(list,featuretype)
+        local coverage = { }
+        local cover    = coveractions[featuretype]
+        for code, replacement in next, list do
+            local unicode     = tounicode(code)
+            local description = descriptions[unicode]
+            if not description then
+                skip = skip + 1
+            elseif type(replacement) == "table" then
+                local r = { }
+                for i=1,#replacement do
+                    local u = tounicode(replacement[i])
+                    r[i] = descriptions[u] and u or unicode
+                end
+                cover(coverage,unicode,r)
+                done = done + 1
+            else
+                local u = tounicode(replacement)
+                if u then
+                    cover(coverage,unicode,{ u })
+                    done = done + 1
+                else
+                    skip = skip + 1
+                end
+            end
+        end
+        return coverage
+    end
+
+    local function prepare_multiple(list,featuretype)
+        local coverage = { }
+        local cover    = coveractions[featuretype]
+        for code, replacement in next, list do
+            local unicode     = tounicode(code)
+            local description = descriptions[unicode]
+            if not description then
+                skip = skip + 1
+            elseif type(replacement) == "table" then
+                local r, n = { }, 0
+                for i=1,#replacement do
+                    local u = tounicode(replacement[i])
+                    if descriptions[u] then
+                        n = n + 1
+                        r[n] = u
+                    end
+                end
+                if n > 0 then
+                    cover(coverage,unicode,r)
+                    done = done + 1
+                else
+                    skip = skip + 1
+                end
+            else
+                local u = tounicode(replacement)
+                if u then
+                    cover(coverage,unicode,{ u })
+                    done = done + 1
+                else
+                    skip = skip + 1
+                end
+            end
+        end
+        return coverage
+    end
+
+    local function prepare_ligature(list,featuretype)
+        local coverage = { }
+        local cover    = coveractions[featuretype]
+        for code, ligature in next, list do
+            local unicode     = tounicode(code)
+            local description = descriptions[unicode]
+            if description then
+                if type(ligature) == "string" then
+                    ligature = { lpegmatch(splitter,ligature) }
+                end
+                local present = true
+                for i=1,#ligature do
+                    local l = ligature[i]
+                    local u = tounicode(l)
+                    if descriptions[u] then
+                        ligature[i] = u
+                    else
+                        present = false
+                        break
+                    end
+                end
+                if present then
+                    cover(coverage,unicode,ligature)
+                    done = done + 1
+                else
+                    skip = skip + 1
+                end
+            else
+                skip = skip + 1
+            end
+        end
+        return coverage
+    end
+
+    local function prepare_kern(list,featuretype)
+        local coverage = { }
+        local cover    = coveractions[featuretype]
+        for code, replacement in next, list do
+            local unicode     = tounicode(code)
+            local description = descriptions[unicode]
+            if description and type(replacement) == "table" then
+                local r = { }
+                for k, v in next, replacement do
+                    local u = tounicode(k)
+                    if u then
+                        r[u] = v
+                    end
+                end
+                if next(r) then
+                    cover(coverage,unicode,r)
+                    done = done + 1
+                else
+                    skip = skip + 1
+                end
+            else
+                skip = skip + 1
+            end
+        end
+        return coverage
+    end
+
+    local function prepare_pair(list,featuretype)
+        local coverage = { }
+        local cover    = coveractions[featuretype]
+        if cover then
+            for code, replacement in next, list do
+                local unicode     = tounicode(code)
+                local description = descriptions[unicode]
+                if description and type(replacement) == "table" then
+                    local r = { }
+                    for k, v in next, replacement do
+                        local u = tounicode(k)
+                        if u then
+                            r[u] = v
+                        end
+                    end
+                    if next(r) then
+                        cover(coverage,unicode,r)
+                        done = done + 1
+                    else
+                        skip = skip + 1
+                    end
+                else
+                    skip = skip + 1
+                end
+            end
+        else
+            report_otf("unknown cover type %a",featuretype)
+        end
+        return coverage
+    end
+
+    local function prepare_chain(list,featuretype,sublookups)
+        -- todo: coveractions
+        local rules    = list.rules
+        local coverage = { }
+        if rules then
+            local rulehash     = { }
+            local rulesize     = 0
+            local sequence     = { }
+            local nofsequences = 0
+            local lookuptype   = types[featuretype]
+            for nofrules=1,#rules do
+                local rule         = rules[nofrules]
+                local current      = rule.current
+                local before       = rule.before
+                local after        = rule.after
+                local replacements = rule.replacements or false
+                local sequence     = { }
+                local nofsequences = 0
+                if before then
+                    for n=1,#before do
+                        nofsequences = nofsequences + 1
+                        sequence[nofsequences] = before[n]
+                    end
+                end
+                local start = nofsequences + 1
+                for n=1,#current do
+                    nofsequences = nofsequences + 1
+                    sequence[nofsequences] = current[n]
+                end
+                local stop = nofsequences
+                if after then
+                    for n=1,#after do
+                        nofsequences = nofsequences + 1
+                        sequence[nofsequences] = after[n]
+                    end
+                end
+                local lookups = rule.lookups or false
+                local subtype = nil
+                if lookups and sublookups then
+                    for k, v in next, lookups do
+                        local lookup = sublookups[v]
+                        if lookup then
+                            lookups[k] = lookup
+                            if not subtype then
+                                subtype = lookup.type
+                            end
+                        else
+                            -- already expanded
+                        end
+                    end
+                end
+                if nofsequences > 0 then -- we merge coverage into one
+                    -- we copy as we can have different fonts
+                    local hashed = { }
+                    for i=1,nofsequences do
+                        local t = { }
+                        local s = sequence[i]
+                        for i=1,#s do
+                            local u = tounicode(s[i])
+                            if u then
+                                t[u] = true
+                            end
+                        end
+                        hashed[i] = t
+                    end
+                    sequence = hashed
+                    -- now we create the rule
+                    rulesize = rulesize + 1
+                    rulehash[rulesize] = {
+                        nofrules,     -- 1
+                        lookuptype,   -- 2
+                        sequence,     -- 3
+                        start,        -- 4
+                        stop,         -- 5
+                        lookups,      -- 6 (6/7 also signal of what to do)
+                        replacements, -- 7
+                        subtype,      -- 8
+                    }
+                    for unic in next, sequence[start] do
+                        local cu = coverage[unic]
+                        if not cu then
+                            coverage[unic] = rulehash -- can now be done cleaner i think
+                        end
+                    end
+                end
+            end
+        end
+        return coverage
+    end
+
+    local dataset = specifications.dataset
+
+    local function report(name,category,position,first,last,sequences)
+        report_otf("injecting name %a of category %a at position %i in [%i,%i] of [%i,%i]",
+            name,category,position,first,last,1,#sequences)
+    end
+
+    local function inject(specification,sequences,sequence,first,last,category,name)
+        local position = specification.position or false
+        if not position then
+            position = specification.prepend
+            if position == true then
+                if trace_loading then
+                    report(name,category,first,first,last,sequences)
+                end
+                insert(sequences,first,sequence)
+                return
+            end
+        end
+        if not position then
+            position = specification.append
+            if position == true then
+                if trace_loading then
+                    report(name,category,last+1,first,last,sequences)
+                end
+                insert(sequences,last+1,sequence)
+                return
+            end
+        end
+        local kind = type(position)
+        if kind == "string" then
+            local index = false
+            for i=first,last do
+                local s = sequences[i]
+                local f = s.features
+                if f then
+                    for k in next, f do
+                        if k == position then
+                            index = i
+                            break
+                        end
+                    end
+                    if index then
+                        break
+                    end
+                end
+            end
+            if index then
+                position = index
+            else
+                position = last + 1
+            end
+        elseif kind == "number" then
+            if position < 0 then
+                position = last - position + 1
+            end
+            if position > last then
+                position = last + 1
+            elseif position < first then
+                position = first
+            end
+        else
+            position = last + 1
+        end
+        if trace_loading then
+            report(name,category,position,first,last,sequences)
+        end
+        insert(sequences,position,sequence)
+    end
+
+    for s=1,#dataset do
+        local specification = dataset[s]
+        local valid = specification.valid -- nowhere used
+        local feature = specification.name or feature
+        if not feature or feature == "" then
+            report_otf("no valid name given for extra feature")
+        elseif not valid or valid(data,specification,feature) then -- anum uses this
+            local initialize = specification.initialize
+            if initialize then
+                -- when false is returned we initialize only once
+                specification.initialize = initialize(specification,data) and initialize or nil
+            end
+            local askedfeatures = specification.features or everywhere
+            local askedsteps    = specification.steps or specification.subtables or { specification.data } or { }
+            local featuretype   = normalized[specification.type or "substitution"] or "substitution"
+            local featureflags  = specification.flags or noflags
+            local featureorder  = specification.order or { feature }
+            local featurechain  = (featuretype == "chainsubstitution" or featuretype == "chainposition") and 1 or 0
+            local nofsteps      = 0
+            local steps         = { }
+            local sublookups    = specification.lookups
+            local category      = nil
+            if sublookups then
+                local s = { }
+                for i=1,#sublookups do
+                    local specification = sublookups[i]
+                    local askedsteps    = specification.steps or specification.subtables or { specification.data } or { }
+                    local featuretype   = normalized[specification.type or "substitution"] or "substitution"
+                    local featureflags  = specification.flags or noflags
+                    local nofsteps      = 0
+                    local steps         = { }
+                    for i=1,#askedsteps do
+                        local list     = askedsteps[i]
+                        local coverage = nil
+                        local format   = nil
+                        if featuretype == "substitution" then
+                            coverage = prepare_substitution(list,featuretype)
+                        elseif featuretype == "ligature" then
+                            coverage = prepare_ligature(list,featuretype)
+                        elseif featuretype == "alternate" then
+                            coverage = prepare_alternate(list,featuretype)
+                        elseif featuretype == "multiple" then
+                            coverage = prepare_multiple(list,featuretype)
+                        elseif featuretype == "kern" then
+                            format   = "kern"
+                            coverage = prepare_kern(list,featuretype)
+                        elseif featuretype == "pair" then
+                            format   = "pair"
+                            coverage = prepare_pair(list,featuretype)
+                        end
+                        if coverage and next(coverage) then
+                            nofsteps = nofsteps + 1
+                            steps[nofsteps] = register(coverage,featuretype,format,feature,nofsteps,descriptions,resources)
+                        end
+                    end
+                    s[i] = {
+                        [stepkey] = steps,
+                        nofsteps  = nofsteps,
+                        type      = types[featuretype],
+                    }
+                end
+                sublookups = s
+            end
+            for i=1,#askedsteps do
+                local list     = askedsteps[i]
+                local coverage = nil
+                local format   = nil
+                if featuretype == "substitution" then
+                    category = "gsub"
+                    coverage = prepare_substitution(list,featuretype)
+                elseif featuretype == "ligature" then
+                    category = "gsub"
+                    coverage = prepare_ligature(list,featuretype)
+                elseif featuretype == "alternate" then
+                    category = "gsub"
+                    coverage = prepare_alternate(list,featuretype)
+                elseif featuretype == "multiple" then
+                    category = "gsub"
+                    coverage = prepare_multiple(list,featuretype)
+                elseif featuretype == "kern" then
+                    category = "gpos"
+                    format   = "kern"
+                    coverage = prepare_kern(list,featuretype)
+                elseif featuretype == "pair" then
+                    category = "gpos"
+                    format   = "pair"
+                    coverage = prepare_pair(list,featuretype)
+                elseif featuretype == "chainsubstitution" then
+                    category = "gsub"
+                    coverage = prepare_chain(list,featuretype,sublookups)
+                elseif featuretype == "chainposition" then
+                    category = "gpos"
+                    coverage = prepare_chain(list,featuretype,sublookups)
+                else
+                    report_otf("not registering feature %a, unknown category",feature)
+                    return
+                end
+                if coverage and next(coverage) then
+                    nofsteps = nofsteps + 1
+                    steps[nofsteps] = register(coverage,featuretype,format,feature,nofsteps,descriptions,resources)
+                end
+            end
+            if nofsteps > 0 then
+                -- script = { lang1, lang2, lang3 } or script = { lang1 = true, ... }
+                for k, v in next, askedfeatures do
+                    if v[1] then
+                        askedfeatures[k] = tohash(v)
+                    end
+                end
+                if featureflags[1] then featureflags[1] = "mark" end
+                if featureflags[2] then featureflags[2] = "ligature" end
+                if featureflags[3] then featureflags[3] = "base" end
+                local steptype = types[featuretype]
+                local sequence = {
+                    chain     = featurechain,
+                    features  = { [feature] = askedfeatures },
+                    flags     = featureflags,
+                    name      = feature, -- redundant
+                    order     = featureorder,
+                    [stepkey] = steps,
+                    nofsteps  = nofsteps,
+                    type      = steptype,
+                }
+                -- position | prepend | append
+                local first, last = getrange(sequences,category)
+                inject(specification,sequences,sequence,first,last,category,feature)
+                -- register in metadata (merge as there can be a few)
+                local features = fontfeatures[category]
+                if not features then
+                    features  = { }
+                    fontfeatures[category] = features
+                end
+                local k = features[feature]
+                if not k then
+                    k = { }
+                    features[feature] = k
+                end
+                --
+                for script, languages in next, askedfeatures do
+                    local kk = k[script]
+                    if not kk then
+                        kk = { }
+                        k[script] = kk
+                    end
+                    for language, value in next, languages do
+                        kk[language] = value
+                    end
+                end
+            end
+        end
+    end
+    if trace_loading then
+        report_otf("registering feature %a, affected glyphs %a, skipped glyphs %a",feature,done,skip)
+    end
+end
+
+otf.enhancers.addfeature = addfeature
+
+local extrafeatures = { }
+local knownfeatures = { }
+
+function otf.addfeature(name,specification)
+    if type(name) == "table" then
+        specification = name
+    end
+    if type(specification) ~= "table" then
+        report_otf("invalid feature specification, no valid table")
+        return
+    end
+    specification, name = validspecification(specification,name)
+    if name and specification then
+        local slot = knownfeatures[name]
+        if slot then
+            -- we overload one .. should be option
+        else
+            slot = #extrafeatures + 1
+            knownfeatures[name] = slot
+        end
+        specification.name  = name -- to be sure
+        extrafeatures[slot] = specification
+     -- report_otf("adding feature %a @ %i",name,slot)
+    end
+end
+
+-- for feature, specification in next, extrafeatures do
+--     addfeature(data,feature,specification)
+-- end
+
+local function enhance(data,filename,raw)
+    for slot=1,#extrafeatures do
+        local specification = extrafeatures[slot]
+        addfeature(data,specification.name,specification)
+    end
+end
+
+otf.enhancers.enhance = enhance
+
+otf.enhancers.register("check extra features",enhance)
+
+-- tlig --
+
+local tlig = { -- we need numbers for some fonts so ...
+ -- endash        = "hyphen hyphen",
+ -- emdash        = "hyphen hyphen hyphen",
+    [0x2013]      = { 0x002D, 0x002D },
+    [0x2014]      = { 0x002D, 0x002D, 0x002D },
+ -- quotedblleft  = "quoteleft quoteleft",
+ -- quotedblright = "quoteright quoteright",
+ -- quotedblleft  = "grave grave",
+ -- quotedblright = "quotesingle quotesingle",
+ -- quotedblbase  = "comma comma",
+}
+
+local tlig_specification = {
+    type     = "ligature",
+    features = everywhere,
+    data     = tlig,
+    order    = { "tlig" },
+    flags    = noflags,
+    prepend  = true,
+}
+
+otf.addfeature("tlig",tlig_specification)
+
+registerotffeature {
+    -- this makes it a known feature (in tables)
+    name        = 'tlig',
+    description = 'tex ligatures',
+}
+
+-- trep
+
+local trep = {
+ -- [0x0022] = 0x201D,
+    [0x0027] = 0x2019,
+ -- [0x0060] = 0x2018,
+}
+
+local trep_specification = {
+    type      = "substitution",
+    features  = everywhere,
+    data      = trep,
+    order     = { "trep" },
+    flags     = noflags,
+    prepend   = true,
+}
+
+otf.addfeature("trep",trep_specification)
+
+registerotffeature {
+    -- this makes it a known feature (in tables)
+    name        = 'trep',
+    description = 'tex replacements',
+}
+
+-- -- tcom (obsolete, was already not set for a while)
+
+-- if characters.combined then
+--
+--     local tcom = { }
+--
+--     local function initialize()
+--         characters.initialize()
+--         for first, seconds in next, characters.combined do
+--             for second, combination in next, seconds do
+--                 tcom[combination] = { first, second }
+--             end
+--         end
+--         -- return false
+--     end
+--
+--     local tcom_specification = {
+--         type       = "ligature",
+--         features   = everywhere,
+--         data       = tcom,
+--         order      = { "tcom" },
+--         flags      = noflags,
+--         initialize = initialize,
+--     }
+--
+--     otf.addfeature("tcom",tcom_specification)
+--
+--     registerotffeature {
+--         name        = 'tcom',
+--         description = 'tex combinations',
+--     }
+--
+-- end
+
+-- anum
+
+local anum_arabic = {
+    [0x0030] = 0x0660,
+    [0x0031] = 0x0661,
+    [0x0032] = 0x0662,
+    [0x0033] = 0x0663,
+    [0x0034] = 0x0664,
+    [0x0035] = 0x0665,
+    [0x0036] = 0x0666,
+    [0x0037] = 0x0667,
+    [0x0038] = 0x0668,
+    [0x0039] = 0x0669,
+}
+
+local anum_persian = {
+    [0x0030] = 0x06F0,
+    [0x0031] = 0x06F1,
+    [0x0032] = 0x06F2,
+    [0x0033] = 0x06F3,
+    [0x0034] = 0x06F4,
+    [0x0035] = 0x06F5,
+    [0x0036] = 0x06F6,
+    [0x0037] = 0x06F7,
+    [0x0038] = 0x06F8,
+    [0x0039] = 0x06F9,
+}
+
+local function valid(data)
+    local features = data.resources.features
+    if features then
+        for k, v in next, features do
+            for k, v in next, v do
+                if v.arab then
+                    return true
+                end
+            end
+        end
+    end
+end
+
+local anum_specification = {
+    {
+        type     = "substitution",
+        features = { arab = { urd = true, dflt = true } },
+        order    = { "anum" },
+        data     = anum_arabic,
+        flags    = noflags, -- { },
+        valid    = valid,
+    },
+    {
+        type     = "substitution",
+        features = { arab = { urd = true } },
+        order    = { "anum" },
+        data     = anum_persian,
+        flags    = noflags, -- { },
+        valid    = valid,
+    },
+}
+
+otf.addfeature("anum",anum_specification) -- todo: only when there is already an arab script feature
+
+registerotffeature {
+    -- this makes it a known feature (in tables)
+    name        = 'anum',
+    description = 'arabic digits',
+}
+
+-- maybe:
+
+-- fonts.handlers.otf.addfeature("hangulfix",{
+--     type     = "substitution",
+--     features = { ["hang"] = { ["*"] = true } },
+--     data     = {
+--         [0x1160] = 0x119E,
+--     },
+--     order    = { "hangulfix" },
+--     flags    = { },
+--     prepend  = true,
+-- })
+
+-- fonts.handlers.otf.features.register {
+--     name        = 'hangulfix',
+--     description = 'fixes for hangul',
+-- }
+
+-- fonts.handlers.otf.addfeature {
+--     name = "stest",
+--     type = "substitution",
+--     data = {
+--         a = "X",
+--         b = "P",
+--     }
+-- }
+-- fonts.handlers.otf.addfeature {
+--     name = "atest",
+--     type = "alternate",
+--     data = {
+--         a = { "X", "Y" },
+--         b = { "P", "Q" },
+--     }
+-- }
+-- fonts.handlers.otf.addfeature {
+--     name = "mtest",
+--     type = "multiple",
+--     data = {
+--         a = { "X", "Y" },
+--         b = { "P", "Q" },
+--     }
+-- }
+-- fonts.handlers.otf.addfeature {
+--     name = "ltest",
+--     type = "ligature",
+--     data = {
+--         X = { "a", "b" },
+--         Y = { "d", "a" },
+--     }
+-- }
+-- fonts.handlers.otf.addfeature {
+--     name = "ktest",
+--     type = "kern",
+--     data = {
+--         a = { b = -500 },
+--     }
+-- }
diff --git a/src/fontloader/misc/fontloader-fonts.lua b/src/fontloader/misc/fontloader-fonts.lua
index 41b95d9..c21389c 100644
--- a/src/fontloader/misc/fontloader-fonts.lua
+++ b/src/fontloader/misc/fontloader-fonts.lua
@@ -259,6 +259,8 @@ if non_generic_context.luatex_fonts.skip_loading ~= true then
         loadmodule('font-osd.lua')
         loadmodule('font-ocl.lua') -- svg needs 0.97 (for fix in memstreams)
 
+        loadmodule('font-otc.lua')
+
         -- type one code
 
         loadmodule('font-onr.lua') -- was font-afm.lua