diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/iterators.lua | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/util/iterators.lua b/util/iterators.lua index a152e7be..5d16d8c1 100644 --- a/util/iterators.lua +++ b/util/iterators.lua @@ -14,6 +14,11 @@ local t_insert = table.insert; local select, next = select, next; local unpack = table.unpack or unpack; --luacheck: ignore 113 143 local pack = table.pack or function (...) return { n = select("#", ...), ... }; end -- luacheck: ignore 143 +local type = type; +local table, setmetatable = table, setmetatable; + +local _ENV = nil; +--luacheck: std none -- Reverse an iterator function it.reverse(f, s, var) @@ -184,4 +189,45 @@ function it.to_table(f, s, var) return t; end +local function _join_iter(j_s, j_var) + local iterators, current_idx = j_s[1], j_s[2]; + local f, s, var = unpack(iterators[current_idx], 1, 3); + if j_var ~= nil then + var = j_var; + end + local ret = pack(f(s, var)); + local var1 = ret[1]; + if var1 == nil then + -- End of this iterator, advance to next + if current_idx == #iterators then + -- No more iterators, return nil + return; + end + j_s[2] = current_idx + 1; + return _join_iter(j_s); + end + return unpack(ret, 1, ret.n); +end +local join_methods = {}; +local join_mt = { + __index = join_methods; + __call = function (t, s, var) --luacheck: ignore 212/t + return _join_iter(s, var); + end; +}; + +function join_methods:append(f, s, var) + table.insert(self, { f, s, var }); + return self, { self, 1 }; +end + +function join_methods:prepend(f, s, var) + table.insert(self, { f, s, var }, 1); + return self, { self, 1 }; +end + +function it.join(f, s, var) + return setmetatable({ {f, s, var} }, join_mt); +end + return it; |