reflect move l-aux -> util-tab.lua

1 files changed, 257 insertions, 0 deletions

diff --git a/lualibs-util-tab.lua b/lualibs-util-tab.lua
new file mode 100644
index 0000000..7950a03
--- /dev/null
+++ b/lualibs-util-tab.lua
@@ -0,0 +1,257 @@
+if not modules then modules = { } end modules ['l-aux'] = {
+    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"
+}
+
+-- for inline, no store split : for s in string.gmatch(str,",* *([^,]+)") do .. end
+
+aux = aux or { }
+
+local concat, format, gmatch = table.concat, string.format, string.gmatch
+local tostring, type = tostring, type
+local lpegmatch = lpeg.match
+
+local P, R, V = lpeg.P, lpeg.R, lpeg.V
+
+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     = lpeg.P(' ')
+local equal     = lpeg.P("=")
+local comma     = lpeg.P(",")
+local lbrace    = lpeg.P("{")
+local rbrace    = lpeg.P("}")
+local nobrace   = 1 - (lbrace+rbrace)
+local nested    = lpeg.P { lbrace * (nobrace + lpeg.V(1))^0 * rbrace }
+local spaces    = space^0
+
+local value     = lpeg.P(lbrace * lpeg.C((nobrace + nested)^0) * rbrace) + lpeg.C((nested + (1-comma))^0)
+
+local key       = lpeg.C((1-equal-comma)^1)
+local pattern_a = (space+comma)^0 * (key * equal * value + key * lpeg.C(""))
+local pattern_c = (space+comma)^0 * (key * equal * value)
+
+local key       = lpeg.C((1-space-equal-comma)^1)
+local pattern_b = spaces * comma^0 * spaces * (key * ((spaces * equal * spaces * value) + lpeg.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
+
+aux.settings_to_hash_pattern_a = pattern_a_s
+aux.settings_to_hash_pattern_b = pattern_b_s
+aux.settings_to_hash_pattern_c = pattern_c_s
+
+function aux.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 aux.settings_to_hash(str,existing)
+    if str and str ~= "" then
+        hash = existing or { }
+        if moretolerant then
+            lpegmatch(pattern_b_s,str)
+        else
+            lpegmatch(pattern_a_s,str)
+        end
+        return hash
+    else
+        return { }
+    end
+end
+
+function aux.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 aux.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     = lpeg.P(lbrace * lpeg.C((nobrace + nested)^0) * rbrace) + lpeg.C((nested + (1-comma))^0)
+local pattern   = lpeg.Ct(value*(separator*value)^0)
+
+-- "aap, {noot}, mies" : outer {} removes, leading spaces ignored
+
+aux.settings_to_array_pattern = pattern
+
+-- we could use a weak table as cache
+
+function aux.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   = lpeg.P(lpeg.Carg(1)*value) / set
+local pattern = value*(separator*value)^0 * lpeg.Carg(1)
+
+function aux.add_settings_to_array(t,str)
+    return lpegmatch(pattern,str,nil,t)
+end
+
+function aux.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 aux.array_to_string(a,separator)
+    if a then
+        return concat(a,separator or ",")
+    else
+        return ""
+    end
+end
+
+function aux.settings_to_set(str,t)
+    t = t or { }
+    for s in gmatch(str,"%s*([^,]+)") do
+        t[s] = true
+    end
+    return t
+end
+
+local value     = lbrace * lpeg.C((nobrace + nested)^0) * rbrace
+local pattern   = lpeg.Ct((space + value)^0)
+
+function aux.arguments_to_table(str)
+    return lpegmatch(pattern,str)
+end
+
+-- temporary here
+
+function aux.getparameters(self,class,parentclass,settings)
+    local sc = self[class]
+    if not sc then
+        sc = table.clone(self[parent])
+        self[class] = sc
+    end
+    aux.settings_to_hash(settings,sc)
+end
+
+-- temporary here
+
+local digit         = lpeg.R("09")
+local period        = lpeg.P(".")
+local zero          = lpeg.P("0")
+local trailingzeros = zero^0 * -digit -- suggested by Roberto R
+local case_1        = period * trailingzeros / ""
+local case_2        = period * (digit - trailingzeros)^1 * (trailingzeros / "")
+local number        = digit^1 * (case_1 + case_2)
+local stripper      = lpeg.Cs((number + 1)^0)
+
+--~ local sample = "bla 11.00 bla 11 bla 0.1100 bla 1.00100 bla 0.00 bla 0.001 bla 1.1100 bla 0.100100100 bla 0.00100100100"
+--~ collectgarbage("collect")
+--~ str = string.rep(sample,10000)
+--~ local ts = os.clock()
+--~ lpegmatch(stripper,str)
+--~ print(#str, os.clock()-ts, lpegmatch(stripper,sample))
+
+lpeg.patterns.strip_zeros = stripper
+
+function aux.strip_zeros(str)
+    return lpegmatch(stripper,str)
+end
+
+function aux.definetable(target) -- defines undefined tables
+    local composed, t = nil, { }
+    for name in gmatch(target,"([^%.]+)") do
+        if composed then
+            composed = composed .. "." .. name
+        else
+            composed = name
+        end
+        t[#t+1] = format("%s = %s or { }",composed,composed)
+    end
+    return concat(t,"\n")
+end
+
+function aux.accesstable(target)
+    local t = _G
+    for name in gmatch(target,"([^%.]+)") do
+        t = t[name]
+    end
+    return t
+end
+
+-- as we use this a lot ...
+
+--~ function aux.cachefunction(action,weak)
+--~     local cache = { }
+--~     if weak then
+--~         setmetatable(cache, { __mode = "kv" } )
+--~     end
+--~     local function reminder(str)
+--~         local found = cache[str]
+--~         if not found then
+--~             found = action(str)
+--~             cache[str] = found
+--~         end
+--~         return found
+--~     end
+--~     return reminder, cache
+--~ end