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authorPhilipp Gesang <phg42.2a@gmail.com>2013-04-28 01:45:34 +0200
committerPhilipp Gesang <phg42.2a@gmail.com>2013-04-28 01:45:34 +0200
commit4821fad2ff58fa8c4fbee58cbb6fe5353e047613 (patch)
tree2775b538f906ca18de8b3a1d8c59d10345ce76f2
parentd16a93579dfec03a0dab4281b45f63d877fc4c88 (diff)
downloadluaotfload-4821fad2ff58fa8c4fbee58cbb6fe5353e047613.tar.gz
Import new font request parser
addressing https://github.com/phi-gamma/luaotfload/issues/4 incomplete for now, only handles file: and name: requests
-rw-r--r--luaotfload-features.lua327
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?