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Diffstat (limited to 'tex/context/base/util-prs.lua')
| -rw-r--r-- | tex/context/base/util-prs.lua | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/tex/context/base/util-prs.lua b/tex/context/base/util-prs.lua new file mode 100644 index 000000000..4580a02b8 --- /dev/null +++ b/tex/context/base/util-prs.lua @@ -0,0 +1,201 @@ +if not modules then modules = { } end modules ['util-prs'] = { + version = 1.001, + comment = "companion to luat-lib.mkiv", + author = "Hans Hagen, PRAGMA-ADE, Hasselt NL", + copyright = "PRAGMA ADE / ConTeXt Development Team", + license = "see context related readme files" +} + +utilities = utilities or {} +utilities.parsers = utilities.parsers or { } +local parsers = utilities.parsers +parsers.patterns = parsers.patterns or { } + +local P, R, V, C, Ct, Carg = lpeg.P, lpeg.R, lpeg.V, lpeg.C, lpeg.Ct, lpeg.Carg +local lpegmatch = lpeg.match +local concat, format, gmatch = table.concat, string.format, string.gmatch +local tostring, type = tostring, type +local sortedhash = table.sortedhash + +local escape, left, right = P("\\"), P('{'), P('}') + +lpeg.patterns.balanced = P { + [1] = ((escape * (left+right)) + (1 - (left+right)) + V(2))^0, + [2] = left * V(1) * right +} + +local space = P(' ') +local equal = P("=") +local comma = P(",") +local lbrace = P("{") +local rbrace = P("}") +local nobrace = 1 - (lbrace+rbrace) +local nested = P { lbrace * (nobrace + V(1))^0 * rbrace } +local spaces = space^0 + +local value = P(lbrace * C((nobrace + nested)^0) * rbrace) + C((nested + (1-comma))^0) + +local key = C((1-equal-comma)^1) +local pattern_a = (space+comma)^0 * (key * equal * value + key * C("")) +local pattern_c = (space+comma)^0 * (key * equal * value) + +local key = C((1-space-equal-comma)^1) +local pattern_b = spaces * comma^0 * spaces * (key * ((spaces * equal * spaces * value) + C(""))) + +-- "a=1, b=2, c=3, d={a{b,c}d}, e=12345, f=xx{a{b,c}d}xx, g={}" : outer {} removes, leading spaces ignored + +local hash = { } + +local function set(key,value) -- using Carg is slower here + hash[key] = value +end + +local pattern_a_s = (pattern_a/set)^1 +local pattern_b_s = (pattern_b/set)^1 +local pattern_c_s = (pattern_c/set)^1 + +parsers.patterns.settings_to_hash_a = pattern_a_s +parsers.patterns.settings_to_hash_b = pattern_b_s +parsers.patterns.settings_to_hash_c = pattern_c_s + +function parsers.make_settings_to_hash_pattern(set,how) + if how == "strict" then + return (pattern_c/set)^1 + elseif how == "tolerant" then + return (pattern_b/set)^1 + else + return (pattern_a/set)^1 + end +end + +function parsers.settings_to_hash(str,existing) + if str and str ~= "" then + hash = existing or { } + lpegmatch(pattern_a_s,str) + return hash + else + return { } + end +end + +function parsers.settings_to_hash_tolerant(str,existing) + if str and str ~= "" then + hash = existing or { } + lpegmatch(pattern_b_s,str) + return hash + else + return { } + end +end + +function parsers.settings_to_hash_strict(str,existing) + if str and str ~= "" then + hash = existing or { } + lpegmatch(pattern_c_s,str) + return next(hash) and hash + else + return nil + end +end + +local separator = comma * space^0 +local value = P(lbrace * C((nobrace + nested)^0) * rbrace) + C((nested + (1-comma))^0) +local pattern = Ct(value*(separator*value)^0) + +-- "aap, {noot}, mies" : outer {} removes, leading spaces ignored + +parsers.patterns.settings_to_array = pattern + +-- we could use a weak table as cache + +function parsers.settings_to_array(str) + if not str or str == "" then + return { } + else + return lpegmatch(pattern,str) + end +end + +local function set(t,v) + t[#t+1] = v +end + +local value = P(Carg(1)*value) / set +local pattern = value*(separator*value)^0 * Carg(1) + +function parsers.add_settings_to_array(t,str) + return lpegmatch(pattern,str,nil,t) +end + +function parsers.hash_to_string(h,separator,yes,no,strict,omit) + if h then + local t, s = { }, table.sortedkeys(h) + omit = omit and table.tohash(omit) + for i=1,#s do + local key = s[i] + if not omit or not omit[key] then + local value = h[key] + if type(value) == "boolean" then + if yes and no then + if value then + t[#t+1] = key .. '=' .. yes + elseif not strict then + t[#t+1] = key .. '=' .. no + end + elseif value or not strict then + t[#t+1] = key .. '=' .. tostring(value) + end + else + t[#t+1] = key .. '=' .. value + end + end + end + return concat(t,separator or ",") + else + return "" + end +end + +function parsers.array_to_string(a,separator) + if a then + return concat(a,separator or ",") + else + return "" + end +end + +function parsers.settings_to_set(str,t) -- tohash? -- todo: lpeg -- duplicate anyway + t = t or { } + for s in gmatch(str,"%s*([^, ]+)") do -- space added + t[s] = true + end + return t +end + +function parsers.simple_hash_to_string(h, separator) + local t = { } + for k, v in sortedhash(h) do + if v then + t[#t+1] = k + end + end + return concat(t,separator or ",") +end + +local value = lbrace * C((nobrace + nested)^0) * rbrace +local pattern = Ct((space + value)^0) + +function parsers.arguments_to_table(str) + return lpegmatch(pattern,str) +end + +-- temporary here (unoptimized) + +function parsers.getparameters(self,class,parentclass,settings) + local sc = self[class] + if not sc then + sc = table.clone(self[parent]) + self[class] = sc + end + parsers.settings_to_hash(settings,sc) +end |