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anselme/ast/Table.lua
Étienne Reuh Fildadut fe351b5ca4 Anselme v2.0.0-alpha rewrite
Woke up and felt like changing a couple things. It's actually been worked on for a while, little at a time...

The goal was to make the language and implementation much simpler. Well I don't know if it really ended up being simpler but it sure is more robust.

Main changes:
* proper first class functions and closures supports! proper scoping rules! no more namespace shenanigans!
* everything is an expression, no more statements! make the implementation both simpler and more complex, but it's much more consistent now! the syntax has massively changed as a result though.
* much more organized and easy to modify codebase: one file for each AST node, no more random fields or behavior set by some random node exceptionally, everything should now follow the same API defined in ast.abstract.Node

Every foundational feature should be implemented right now. The vast majority of things that were possible in v2 are possible now; some things aren't, but that's usually because v2 is a bit more sane.
The main missing things before a proper release are tests and documentation. There's a few other things that might be implemented later, see the ideas.md file.
2023-12-22 13:25:28 +01:00

85 lines
2.2 KiB
Lua

local ast = require("ast")
local Branched, Struct, Nil = ast.Branched, ast.Struct, ast.Nil
local operator_priority = require("common").operator_priority
local Table
Table = ast.abstract.Runtime {
type = "table",
format_priority = operator_priority["*_"],
-- note: technically this isn't mutable, only .branched is
-- note: this a Branched of Struct, and we *will* forcefully mutate the tuples, so make sure to not disseminate any reference to them outside the Table
-- unless you want rumors about mutable structs to spread
branched = nil,
init = function(self, state, from_struct)
from_struct = from_struct or Struct:new()
self.branched = Branched:new(state, from_struct:copy())
end,
_format = function(self, ...)
return "*"..self.branched:format_right(...)
end,
traverse = function(self, fn, ...)
fn(self.branched, ...)
end,
-- Table is always created from an evaluated Struct, so no need to _eval here
-- create copy of the table in branch if not here
-- do this before any mutation
-- return the struct for the current branch
_prepare_branch = function(self, state)
if not self.branched:in_branch(state) then
self.branched:set(state, self.branched:get(state):copy())
end
return self.branched:get(state)
end,
get = function(self, state, key)
local s = self.branched:get(state)
return s:get(key)
end,
set = function(self, state, key, val)
local s = self:_prepare_branch(state)
local hash = key:hash()
if Nil:is(val) then
s.table[hash] = nil
else
s.table[hash] = { key, val }
end
end,
has = function(self, state, key)
local s = self.branched:get(state)
return s:has(key)
end,
iter = function(self, state)
local t, h = self.branched:get(state).table, nil
return function()
local e
h, e = next(t, h)
if h == nil then return nil
else return e[1], e[2]
end
end
end,
to_struct = function(self, state)
return self.branched:get(state):copy()
end,
to_lua = function(self, state)
return self.branched:get(state):to_lua(state)
end,
copy = function(self, state)
return Table:new(state, self:to_struct(state))
end
}
package.loaded[...] = Table
Branched, Struct, Nil = ast.Branched, ast.Struct, ast.Nil
return Table