diff options
Diffstat (limited to 'luaotfload-features.lua')
| -rw-r--r-- | luaotfload-features.lua | 327 |
1 files changed, 274 insertions, 53 deletions
diff --git a/luaotfload-features.lua b/luaotfload-features.lua index 0171dba..cd639b6 100644 --- a/luaotfload-features.lua +++ b/luaotfload-features.lua @@ -26,7 +26,7 @@ function fonts.definers.getspecification(str) return "", str, "", ":", str end -local feature_list = { } +local old_feature_list = { } local report = logs.names_report @@ -64,20 +64,23 @@ local isstyle = function (request) for _,v in next, request do local stylename = supported[v] if stylename then - feature_list.style = stylename + old_feature_list.style = stylename elseif stringfind(v, "^s=") then --- after all, we want everything after the second byte ... local val = stringsub(v, 3) - feature_list.optsize = val + old_feature_list.optsize = val elseif stylename == false then report("log", 0, - "load font", "unsupported font option: %s", v) + "load", "unsupported font option: %s", v) elseif not stringis_empty(v) then - feature_list.style = stringgsub(v, "[^%a%d]", "") + old_feature_list.style = stringgsub(v, "[^%a%d]", "") end end end +--- TODO an option to dump the default features for a script would make +--- a nice addition to luaotfload-tool + local defaults = { dflt = { "ccmp", "locl", "rlig", "liga", "clig", @@ -131,17 +134,22 @@ defaults.tibt = defaults.khmr defaults.lao = defaults.thai +--[[doc-- +Which features are active by default depends on the script requested. +--doc]]-- + --- (string, string) dict -> (string, string) dict local set_default_features = function (speclist) + speclist = speclist or { } local script = speclist.script or "dflt" - report("log", 0, "load font", + report("log", 0, "load", "auto-selecting default features for script: %s", script) local requested = defaults[script] if not requested then - report("log", 0, "load font", + report("log", 0, "load", "no defaults for script “%s”, falling back to “dflt”", script) requested = defaults.dflt @@ -149,9 +157,7 @@ local set_default_features = function (speclist) for i=1, #requested do local feat = requested[i] - if speclist[feat] ~= false then - speclist[feat] = true - end + if speclist[feat] ~= false then speclist[feat] = true end end for feat, state in next, global_defaults do @@ -163,14 +169,15 @@ local set_default_features = function (speclist) return speclist end -local function issome () feature_list.lookup = 'file' end -local function isfile () feature_list.lookup = 'file' end -local function isname () feature_list.lookup = 'name' end -local function thename(s) feature_list.name = s end -local function issub (v) feature_list.sub = v end -local function istrue (s) feature_list[s] = true end -local function isfalse(s) feature_list[s] = false end -local function iskey (k,v) feature_list[k] = v end +-- --[==[obsolete-- +local function issome () old_feature_list.lookup = 'name' end +local function isfile () old_feature_list.lookup = 'file' end +local function isname () old_feature_list.lookup = 'name' end +local function thename(s) old_feature_list.name = s end +local function issub (v) old_feature_list.sub = v end +local function istrue (s) old_feature_list[s] = true end +local function isfalse(s) old_feature_list[s] = false end +local function iskey (k,v) old_feature_list[k] = v end local P, S, R, C = lpeg.P, lpeg.S, lpeg.R, lpeg.C @@ -191,54 +198,268 @@ local somevalue = sometext/istrue local subvalue = P("(") * (C(P(1-S("()"))^1)/issub) * P(")") -- for Kim local option = spaces * (keyvalue + falsevalue + truevalue + somevalue) * spaces local options = P(":") * spaces * (P(";")^0 * option)^0 -local pattern = (filename + fontname) * subvalue^0 * stylespec^0 * options^0 - -local function colonized(specification) -- xetex mode - feature_list = { } - lpeg.match(pattern,specification.specification) - feature_list = set_default_features(feature_list) - if feature_list.style then - specification.style = feature_list.style - feature_list.style = nil +local oldsyntax = (filename + fontname) * subvalue^0 * stylespec^0 * options^0 + +--- to be annihilated +local function old_behavior (specification) -- xetex mode + old_feature_list = { } + lpeg.match(oldsyntax,specification.specification) + old_feature_list = set_default_features(old_feature_list) + if old_feature_list.style then + specification.style = old_feature_list.style + old_feature_list.style = nil end - if feature_list.optsize then - specification.optsize = feature_list.optsize - feature_list.optsize = nil + if old_feature_list.optsize then + specification.optsize = old_feature_list.optsize + old_feature_list.optsize = nil end - if feature_list.name then - if resolvers.findfile(feature_list.name, "tfm") then - feature_list.lookup = "file" - feature_list.name = file.addsuffix(feature_list.name, "tfm") - elseif resolvers.findfile(feature_list.name, "ofm") then - feature_list.lookup = "file" - feature_list.name = file.addsuffix(feature_list.name, "ofm") + if old_feature_list.name then + if resolvers.findfile(old_feature_list.name, "tfm") then + old_feature_list.lookup = "file" + old_feature_list.name = file.addsuffix(old_feature_list.name, "tfm") + elseif resolvers.findfile(old_feature_list.name, "ofm") then + old_feature_list.lookup = "file" + old_feature_list.name = file.addsuffix(old_feature_list.name, "ofm") end - specification.name = feature_list.name - feature_list.name = nil + specification.name = old_feature_list.name + old_feature_list.name = nil end --- this test overwrites valid file: requests for xetex bracket --- syntax --- if feature_list.lookup then --- specification.lookup = feature_list.lookup --- feature_list.lookup = nil --- end - if feature_list.sub then - specification.sub = feature_list.sub - feature_list.sub = nil + if old_feature_list.lookup then + specification.lookup = old_feature_list.lookup + old_feature_list.lookup = nil end - if not feature_list.mode then + if old_feature_list.sub then + specification.sub = old_feature_list.sub + old_feature_list.sub = nil + end + if not old_feature_list.mode then -- if no mode is set, use our default - feature_list.mode = fonts.mode + old_feature_list.mode = fonts.mode end - specification.features.normal = fonts.handlers.otf.features.normalize(feature_list) - --inspect(specification) - --os.exit() + specification.features.normal = fonts.handlers.otf.features.normalize(old_feature_list) return specification end -fonts.definers.registersplit(":",colonized,"cryptic") -fonts.definers.registersplit("", colonized,"more cryptic") -- catches \font\text=[names] +--fonts.definers.registersplit(":",old_behavior,"cryptic") +--fonts.definers.registersplit("", old_behavior,"more cryptic") -- catches \font\text=[names] +--obsolete]==]-- + +----------------------------------------------------------------------- +--- request syntax parser 2.2 +----------------------------------------------------------------------- +--- the luaotfload font request syntax (see manual) +--- has a canonical form: +--- +--- \font<csname>=<prefix>:<identifier>:<features> +--- +--- where +--- <csname> is the control sequence that activates the font +--- <prefix> is either “file” or “name”, determining the lookup +--- <identifer> is either a file name (no path) or a font +--- name, depending on the lookup +--- <features> is a list of switches or options, separated by +--- semicolons or commas; a switch is of the form “+” foo +--- or “-” foo, options are of the form lhs “=” rhs +--- +--- however, to ensure backward compatibility we also have +--- support for Xetex-style requests. +--- +--- for the Xetex emulation see: +--- · The XeTeX Reference Guide by Will Robertson, 2011 +--- · The XeTeX Companion by Michel Goosens, 2010 +--- · About XeTeX by Jonathan Kew, 2005 +--- +--- +--- caueat emptor. +--- the request is parsed into one of **four** different +--- lookup categories: the regular ones, file and name, +--- as well as the Xetex compatibility ones, path and anon. +--- (maybe a better choice of identifier would be “ambig”.) +--- +--- according to my reconstruction, the correct chaining +--- of the lookups for each category is as follows: +--- +--- | File -> ( db/filename lookup; +--- db/basename lookup; +--- kpse.find_file() ) +--- | Name -> ( names.resolve() ) +--- | Path -> ( db/filename lookup; +--- db/basename lookup; +--- kpse.find_file(); +--- fullpath lookup ) +--- | Anon -> ( names.resolve(); (* most general *) +--- db/filename lookup; +--- db/basename lookup; +--- kpse.find_file(); +--- fullpath lookup ) +--- +--- the database should be generated only if the chain has +--- been completed, and then only once. +--- +--- caching of successful lookups is essential. we need +--- an additional subtable "cached" in the database. it +--- should be nil’able by issuing fontdbutil --flush or +--- something. if a cache miss is followed by a successful +--- lookup, then it will be counted as new addition to the +--- cache. we also need a config option to ignore caching. +--- +--- also everything has to be finished by tomorrow at noon. +--- +----------------------------------------------------------------------- + + +local stringlower = string.lower + +local toboolean = function (s) + if s == "true" then return true end + if s == "false" then return false end +--if s == "yes" then return true end --- Context style +--if s == "no" then return false end + return s +end + +local lpegmatch = lpeg.match +local P, S, R = lpeg.P, lpeg.S, lpeg.R +local C, Cc, Cf, Cg, Cs, Ct + = lpeg.C, lpeg.Cc, lpeg.Cf, lpeg.Cg, lpeg.Cs, lpeg.Ct + +--- terminals and low-level classes ----------------------------------- +--- note we could use the predefined ones from lpeg.patterns +local dot = P"." +local colon = P":" +local featuresep = S",;" +local slash = P"/" +local equals = P"=" +local lbrk, rbrk = P"[", P"]" + +local spacing = S" \t\v" +local ws = spacing^0 + +local digit = R"09" +local alpha = R("az", "AZ") +local anum = alpha + digit +local decimal = digit^1 * (dot * digit^0)^-1 + +--- modifiers --------------------------------------------------------- +--[[doc-- + The slash notation: called “modifiers” (Kew) or “font options” + (Robertson, Goosens) + we only support the shorthands for italic / bold / bold italic + shapes, the rest is ignored. +--doc]]-- +local style_modifier = (P"BI" + P"IB" + P"bi" + P"ib" + S"biBI") + / stringlower +local other_modifier = P"S=" * decimal --- optical size; unsupported + + P"AAT" + P"aat" --- apple stuff; unsupported + + P"ICU" + P"icu" --- not applicable + + P"GR" + P"gr" --- sil stuff; unsupported +local garbage_modifier = ((1 - colon - slash)^0 * Cc(false)) +local modifier = slash * (other_modifier --> ignore + + Cs(style_modifier) --> collect + + garbage_modifier) --> warn +local modifier_list = Cg(Ct(modifier^0), "modifiers") + +--- lookups ----------------------------------------------------------- +local fontname = C((1-S"/:(")^1) --- like luatex-fonts +local prefixed = P"name:" * ws * Cg(fontname, "name") + + P"file:" * ws * Cg(fontname, "file") +local unprefixed = Cg(fontname, "anon") +local path_lookup = lbrk * Cg(C((1-rbrk)^1), "path") * rbrk + +--- features ---------------------------------------------------------- +local field = (anum + S"+-.")^1 --- sic! +--- assignments are “lhs=rhs” +--- switches are “+key” | “-key” +local assignment = C(field) * ws * equals * ws * (field / toboolean) +local switch = P"+" * ws * C(field) * Cc(true) + + P"-" * ws * C(field) * Cc(false) + + C(field) * Cc(true) -- catch crap +local feature_expr = ws * Cg(assignment + switch) * ws +local feature_list = Cf(Ct"" + * feature_expr + * (featuresep * feature_expr)^0 + , rawset) + * featuresep^-1 + +--- top-level rules --------------------------------------------------- +--- \font\foo=<specification>:<features> +local features = Cg(feature_list, "features") +local specification = (prefixed + unprefixed) * modifier_list^-1 +local font_request = Ct(path_lookup * (colon^-1 * features)^-1 + + specification * (colon * features)^-1) + +-- lpeg.print(font_request) +--- new parser: 632 rules +--- old parser: 230 rules + +local import_values = { + --- That’s what the 1.x parser did, not quite as graciously, + --- with an array of branch expressions. + "style", "optsize", "lookup", "sub" --[[‽]], "mode", +} + +local handle_name = function (specification, raw) + --- FIXME only file: and name: atm + local name = raw.file or raw.name + local lookup + --- why is this here? + --- TODO should we keep this, check if it applies only to tfm and + --- ofm, and test formats by a defined list! + if resolvers.findfile(name, "tfm") then + lookup = "file" + name = file.addsuffix(name, "tfm") + elseif resolvers.findfile(name, "ofm") then + lookup = "file" + name = file.addsuffix(name, "ofm") + end + return name, lookup +end + +--- spec -> spec +local handle_request = function (specification) + local request = lpegmatch(font_request, + specification.specification) + request.features = set_default_features(request.features) + + local name, lookup = handle_name(specification, request) + if name then + specification.name = name + specification.lookup = lookup or specification.lookup + end + + for n=1, #import_values do + local feat = import_values[n] + local newvalue = request.features[feat] + if newvalue then + specification[feat] = request.features[feat] + request.features[feat] = nil + end + end + --- The next line sets the “rand” feature to “random”; I haven’t + --- investigated it any further (luatex-fonts-ext), so it will + --- just stay here. + specification.features.normal + = fonts.handlers.otf.features.normalize(request.features) + return specification +end + +local compare_requests = function (spec) + local old = old_behavior(spec) + local new = handle_request(spec) + return new +end + +fonts.definers.registersplit(":", compare_requests, "cryptic") +fonts.definers.registersplit("", compare_requests, "more cryptic") -- catches \font\text=[names] + +--fonts.definers.registersplit(":", handle_request, "cryptic") +--fonts.definers.registersplit("", handle_request, "more cryptic") -- catches \font\text=[names] + +--fonts.definers.registersplit(":",old_behavior,"cryptic") +--fonts.definers.registersplit("", old_behavior,"more cryptic") -- catches \font\text=[names] --- TODO below section is literally the same in luatex-fonts-def --- why is it here? |