dfhack/library/lua/utils.lua

139 lines
3.3 KiB
Lua

local _ENV = mkmodule('utils')
-- Comparator function
function compare(a,b)
if a < b then
return -1
elseif a > b then
return 1
else
return 0
end
end
-- Sort strings; compare empty last
function compare_name(a,b)
if a == '' then
if b == '' then
return 0
else
return 1
end
elseif b == '' then
return -1
else
return compare(a,b)
end
end
--[[
Sort items in data according to ordering.
Each ordering spec is a table with possible fields:
* key = function(value)
Computes comparison key from a data value. Not called on nil.
* key_table = function(data)
Computes a key table from the data table in one go.
* compare = function(a,b)
Comparison function. Defaults to compare above.
Called on non-nil keys; nil sorts last.
* nil_first
If true, nil keys are sorted first instead of last.
* reverse
If true, sort non-nil keys in descending order.
Returns a table of integer indices into data.
--]]
function make_sort_order(data,ordering)
-- Compute sort keys and comparators
local keys = {}
local cmps = {}
local size = data.n or #data
for i=1,#ordering do
local order = ordering[i]
if order.key_table then
keys[i] = order.key_table(data)
elseif order.key then
local kt = {}
local kf = order.key
for j=1,size do
if data[j] == nil then
kt[j] = nil
else
kt[j] = kf(data[j])
end
end
keys[i] = kt
else
keys[i] = data
end
cmps[i] = order.compare or compare
end
-- Make an order table
local index = {}
for i=1,size do
index[i] = i
end
-- Sort the ordering table
table.sort(index, function(ia,ib)
for i=1,#keys do
local ka = keys[i][ia]
local kb = keys[i][ib]
-- Sort nil keys to the end
if ka == nil then
if kb ~= nil then
return ordering[i].nil_first
end
elseif kb == nil then
return not ordering[i].nil_first
else
local cmpv = cmps[i](ka,kb)
if ordering[i].reverse then
cmpv = -cmpv
end
if cmpv < 0 then
return true
elseif cmpv > 0 then
return false
end
end
end
return ia < ib -- this should ensure stable sort
end)
return index
end
--[[
Recursively assign data into a table.
--]]
function assign(tgt,src)
if df.isvalid(tgt) == 'ref' then
df.assign(tgt, src)
elseif type(tgt) == 'table' then
for k,v in pairs(src) do
if type(v) == 'table' or df.isvalid(v) == 'ref' then
local cv = tgt[k]
if cv == nil then
cv = {}
tgt[k] = cv
end
assign(cv, v)
else
tgt[k] = v
end
end
else
error('Invalid assign target type: '..tostring(tgt))
end
return tgt
end
return _ENV