diff options
Diffstat (limited to 'utils.lua')
| -rw-r--r-- | utils.lua | 334 |
1 files changed, 0 insertions, 334 deletions
diff --git a/utils.lua b/utils.lua deleted file mode 100644 index d45dd2d..0000000 --- a/utils.lua +++ /dev/null @@ -1,334 +0,0 @@ --- A collection of helper utility functions --- -local match, gmatch, gsub = string.match, string.gmatch, string.gsub -local function is_list(t) - if type(t) ~= 'table' then - return false - end - local i = 1 - for _ in pairs(t) do - if t[i] == nil then - return false - end - i = i + 1 - end - return true -end - -local function size(t) - local n = 0 - for _ in pairs(t) do - n = n + 1 - end - return n -end - -local repr_behavior = function(x) - local mt = getmetatable(x) - if mt then - local fn = rawget(mt, "__repr") - if fn then return fn(x) end - end -end -local function repr(x, mt_behavior) - -- Create a string representation of the object that is close to the lua code that will - -- reproduce the object (similar to Python's "repr" function) - mt_behavior = mt_behavior or repr_behavior - local x_type = type(x) - if x_type == 'table' then - local ret = mt_behavior(x) - if ret then return ret end - local ret = {} - local i = 1 - for k, v in pairs(x) do - if k == i then - ret[#ret+1] = repr(v, mt_behavior) - i = i + 1 - elseif type(k) == 'string' and match(k,"[_a-zA-Z][_a-zA-Z0-9]*") then - ret[#ret+1] = k.."= "..repr(v, mt_behavior) - else - ret[#ret+1] = "["..repr(k, mt_behavior).."]= "..repr(v, mt_behavior) - end - end - return "{"..table.concat(ret, ", ").."}" - elseif x_type == 'string' then - local escaped = gsub(x, "\\", "\\\\") - escaped = gsub(escaped, "\n", "\\n") - escaped = gsub(escaped, '"', '\\"') - escaped = gsub(escaped, "[%c%z]", function(c) return ("\\%03d"):format(c:byte()) end) - return '"'..escaped..'"' - else - return tostring(x) - end -end - -local stringify_behavior = function(x) - local mt = getmetatable(x) - if mt then - local fn = rawget(mt, "__tostring") - if fn then return fn(x) end - end -end -local function stringify(x) - if type(x) == 'string' then - return x - else - return repr(x, stringify_behavior) - end -end - -local function split(str, sep) - if sep == nil then - sep = "%s" - end - local ret = {} - for chunk in gmatch(str, "[^"..sep.."]+") do - ret[#ret+1] = chunk - end - return ret -end - -local function remove_from_list(list, item) - local deleted, N = 0, #list - for i=1,N do - if list[i] == item then - deleted = deleted + 1 - else - list[i-deleted] = list[i] - end - end - for i=N-deleted+1,N do list[i] = nil end -end - -local function accumulate(co) - local bits = {} - for bit in coroutine.wrap(co) do - bits[#bits+1] = bit - end - return bits -end - -local function nth_to_last(list, n) - return list[#list - n + 1] -end - -local function keys(t) - local ret = {} - for k in pairs(t) do - ret[#ret+1] = k - end - return ret -end - -local function values(t) - local ret = {} - for _,v in pairs(t) do - ret[#ret+1] = v - end - return ret -end - -local function set(list) - local ret = {} - for i=1,#list do - ret[list[i]] = true - end - return ret -end - -local function deduplicate(list) - local seen, deleted = {}, 0 - for i, item in ipairs(list) do - if seen[item] then - deleted = deleted + 1 - else - seen[item] = true - list[i-deleted] = list[i] - end - end -end - -local function sum(t) - local tot = 0 - for i=1,#t do - tot = tot + t[i] - end - return tot -end - -local function product(t) - if #t > 5 and 0 < t[1] and t[1] < 1 then - local log, log_prod = math.log, 0 - for i=1,#t do - log_prod = log_prod + log(t[i]) - end - return math.exp(log_prod) - else - local prod = 1 - for i=1,#t do - prod = prod * t[i] - end - return prod - end -end - -local function all(t) - for i=1,#t do - if not t[i] then return false end - end - return true -end - -local function any(t) - for i=1,#t do - if t[i] then return true end - end - return false -end - -local function min(list, keyFn) - if keyFn == nil then - keyFn = (function(x) - return x - end) - end - if type(keyFn) == 'table' then - local keyTable = keyFn - keyFn = function(k) - return keyTable[k] - end - end - local best = list[1] - local bestKey = keyFn(best) - for i = 2, #list do - local key = keyFn(list[i]) - if key < bestKey then - best, bestKey = list[i], key - end - end - return best -end - -local function max(list, keyFn) - if keyFn == nil then - keyFn = (function(x) - return x - end) - end - if type(keyFn) == 'table' then - local keyTable = keyFn - keyFn = function(k) - return keyTable[k] - end - end - local best = list[1] - local bestKey = keyFn(best) - for i = 2, #list do - local key = keyFn(list[i]) - if key > bestKey then - best, bestKey = list[i], key - end - end - return best -end - -local function sort(list, keyFn, reverse) - if keyFn == nil then - keyFn = (function(x) - return x - end) - end - if reverse == nil then - reverse = false - end - if type(keyFn) == 'table' then - local keyTable = keyFn - keyFn = function(k) - return keyTable[k] - end - end - table.sort(list, reverse - and (function(x,y) return keyFn(x) > keyFn(y) end) - or (function(x,y) return keyFn(x) < keyFn(y) end)) - return list -end - -local function equivalent(x, y, depth) - depth = depth or 0 - if rawequal(x, y) then - return true - end - if type(x) ~= type(y) then - return false - end - if type(x) ~= 'table' then return false end - if getmetatable(x) ~= getmetatable(y) then - return false - end - if depth >= 99 then - error("Exceeded maximum comparison depth") - end - local checked = {} - for k, v in pairs(x) do - if not equivalent(y[k], v, depth + 1) then - return false - end - checked[k] = true - end - for k, v in pairs(y) do - if not checked[k] and not equivalent(x[k], v, depth + 1) then - return false - end - end - return true -end - -local function key_for(t, value) - for k, v in pairs(t) do - if v == value then - return k - end - end - return nil -end - -local function clamp(x, min, max) - if x < min then - return min - elseif x > max then - return max - else - return x - end -end - -local function mix(min, max, amount) - return (1 - amount) * min + amount * max -end - -local function sign(x) - if x == 0 then - return 0 - elseif x < 0 then - return -1 - else - return 1 - end -end - -local function round(x, increment) - if increment == nil then - increment = 1 - end - if x >= 0 then - return math.floor(x / increment + .5) * increment - else - return math.ceil(x / increment - .5) * increment - end -end - -return {is_list=is_list, size=size, repr=repr, stringify=stringify, split=split, - remove_from_list=remove_from_list, accumulate=accumulate, nth_to_last=nth_to_last, - keys=keys, values=values, set=set, deduplicate=deduplicate, sum=sum, product=product, - all=all, any=any, min=min, max=max, sort=sort, equivalent=equivalent, key_for=key_for, - clamp=clamp, mix=mix, round=round} |