wyvern/luadash.lua
2018-07-26 10:59:05 +01:00

359 lines
7.1 KiB
Lua

-- luadash, from https://github.com/tmpim/luadash, not actually mine
-- It's bundled with the Wyvern source code here because laziness
-- I also added the Levenstein (probably spelt that wrong) distance implementation to it, as it's useful.
local _mt, _ = {}, {}
setmetatable(_, _mt)
local function skip1(f)
return function(x, _, ...)
return f(x, ...)
end
end
function _.expect(n, arg, t, v)
if t == 'value' then
if v == nil then
return error(('%s: bad argument #%d (got nil)'):format(n, arg))
end
elseif type(v) ~= t then
return error(('%s: bad argument #%d (expected %s, got %s)'):format(n, arg, t, type(v)))
end
end
function _.partial(f, ...)
_.expect('partial', 1, 'function', f)
local args = table.pack(...)
return function(...)
local args2, actual = table.pack(...), { }
for i = 1, args.n do
actual[i] = args[i]
end
for i = 1, args2.n do
actual[args.n + i] = args2[i]
end
return f(unpack(actual, 1, args.n + args2.n))
end
end
function _.map_with_key(tab, f)
_.expect('map_with_key', 1, 'table', tab)
_.expect('map_with_key', 2, 'function', f)
local out = {}
for k, v in pairs(tab) do
local k, v = f(k, v)
out[k] = v
end
return out
end
function _.reduce_with_index(tab, f, z)
_.expect('reduce_with_index', 1, 'table', tab)
_.expect('reduce_with_index', 2, 'function', f)
_.expect('reduce_with_index', 3, 'value', z)
local out = z
for i = 1, #tab do
out = f(out, i, tab[i])
end
return out
end
function _.reduce(tab, f, z)
return _.reduce_with_index(tab, skip1(f), z)
end
function _.apply(f, t)
_.expect('apply', 1, 'function', f)
_.expect('apply', 2, 'table', t)
return f(unpack(t, 1, #t))
end
function _.map(t1, f, ...)
_.expect('map', 1, 'table', t1)
_.expect('map', 2, 'function', f)
return _.flat_map(t1, function(...) return { (f(...)) } end, ...)
end
function _.zip(...)
local args = table.pack(...)
for i = 1, args.n do
_.expect('zip', 1, 'table', args[i])
end
return _.map(function(...) return {...} end, ...)
end
function _.push(t, ...)
_.expect('push', 1, 'table', t)
local args = table.pack(...)
for i = 1, args.n do
table.insert(t, args[i])
end
return t
end
function _.intersperse(t, x)
_.expect('intersperse', 1, 'table', t)
local out = {}
for i = 1, #t, 1 do
_.push(out, t[i], x)
end
return out
end
function _.flatten(t)
_.expect('flatten', 1, 'table', t)
local out, li = {}, 1
for i = 1, #t do
if type(t[i]) == 'table' then
for j = 1, #t[i] do
out[li] = t[i][j]
li = li + 1
end
else
out[li] = t[i]
li = li + 1
end
end
return out
end
function _.flat_map(t1, f, ...)
_.expect('flat_map', 1, 'table', t1)
_.expect('flat_map', 2, 'function', f)
local args, n = table.pack(t1, ...), 0
for i = 1, args.n do
_.expect('flat_map', 1 + i, 'table', args[i])
n = math.max(n, #args[i])
end
local out, li = {}, 0
for i = 1, n do
local these = {}
for j = 1, args.n do
these[j] = args[j][i]
end
local r = _.apply(f, these)
if type(r) == 'table' then
for i = 1, #r do
out[li + i] = r[i]
end
li = li + #r
else
out[li + 1] = r
li = li + 1
end
end
return out
end
function _.filter(t, p)
_.expect('filter', 1, 'table', t)
_.expect('filter', 2, 'function', p)
local out, li = {}, 1
for i = 1, #t do
if p(t[i]) then
out[li] = t[i]
li = li + 1
end
end
return out
end
function _.id(v)
_.expect('id', 1, 'value', v)
return v
end
function _.sort_by(t, f)
_.expect('sort_by', 1, 'table', t)
_.expect('sort_by', 2, 'function', f)
local nt = _.map(t, _.id)
table.sort(nt, function(a, b) return f(a) < f(b) end)
return nt
end
function _.sort(t)
_.expect('sort', 1, 'table', t)
return _.sort_by(t, _.id)
end
function _.sample_size(t, n)
_.expect('sample_size', 1, 'table', t)
_.expect('sample_size', 2, 'number', n)
if #t <= n then
return t
end
local src = _.keys(t)
local out = {}
for i = 1, n do
local k = _.sample(src)
out[i] = t[k]
src[k] = src[#src]
src[#src] = nil
end
return out
end
function _.sample(t)
_.expect('sample', 1, 'table', t)
return t[math.random(1, #t)]
end
function _.head(t)
_.expect('head', 1, 'table', t)
return t[1]
end
function _.tail(t)
_.expect('tail', 1, 'table', t)
local out = {}
for i = 2, #t do
out[i - 1] = t[i]
end
return out
end
function _.every(t, p)
_.expect('every', 1, 'table', t)
_.expect('every', 1, 'function', p)
for i = 1, #t do
if not p(t[i]) then
return false
end
end
return true
end
function _.some(t, p)
_.expect('some', 1, 'table', t)
_.expect('some', 1, 'function', p)
for i = 1, #t do
if p(t[i]) then
return true
end
end
return false
end
function _.initial(t)
_.expect('initial', 1, 'table', t)
local out = {}
for i = 1, #t - 1 do
out[i] = t[i]
end
return out
end
function _.last(t)
_.expect('last', 1, 'table', t)
return t[#t]
end
function _.nth(t, i)
_.expect('nth', 1, 'table', t)
_.expect('nth', 2, 'value', i)
return t[i]
end
function _.keys(t)
_.expect('keys', 1, 'table', t)
local out, i = {}, 1
for k, v in pairs(t) do
out[i] = k
i = i + 1
end
return out
end
function _.values(t)
_.expect('values', 1, 'table', t)
local out, i = {}, 1
for k, v in pairs(t) do
out[i] = v
i = i + 1
end
return out
end
function _mt.__call(_, x)
local function wrap(f)
return function(...)
return _(f(...))
end
end
if type(x) == 'table' then
return setmetatable(x,
{ __index = function(t, k)
return wrap(_[k])
end })
else
return x
end
end
function _.distance(str1, str2)
local v0 = {}
local v1 = {}
for i = 0, #str2 do
v0[i] = i
end
for i = 0, #str1 - 1 do
v1[0] = i + 1
for j = 0, #str2 - 1 do
local delCost = v0[j + 1] + 1
local insertCost = v1[j] + 1
local subCost
if str1:sub(i + 1, i + 1) == str2:sub(j + 1, j + 1) then
subCost = v0[j]
else
subCost = v0[j] + 1
end
v1[j + 1] = math.min(delCost, insertCost, subCost)
end
local t = v0
v0 = v1
v1 = t
end
return v0[#str2]
end
_.ops = {
plus = function(a, b) return a + b end,
minus = function(a, b) return a - b end,
times = function(a, b) return a * b end,
over = function(a, b) return a / b end,
power = function(a, b) return a ^ b end,
modulo = function(a, b) return a % b end,
remainder = function(a, b) return a % b end,
rem = function(a, b) return a % b end,
mod = function(a, b) return a % b end,
conj = function(a, b) return a and b end,
disj = function(a, b) return a or b end,
equals = function(a, b) return a == b end,
divisible_by = function(a, b)
return b % a == 0
end,
['>'] = function(a, b) return a > b end,
['>='] = function(a, b) return a >= b end,
['<'] = function(a, b) return a < b end,
['<='] = function(a, b) return a <= b end,
}
function string.starts_with(self, s)
_.expect('starts_with', 1, 'string', s)
return self:find('^' .. s) ~= nil
end
return _