nomsu/core/metaprogramming.nom

#!/usr/bin/env nomsu -V2.4.4.3
#
    This File contains actions for making actions and compile-time actions and some helper
    functions to make that easier.

lua> "NOMSU_CORE_VERSION = 4"
lua> ".."
    nomsu.COMPILE_ACTIONS["% -> %"] = function(nomsu, tree, \%args, \%body)
        local lua = LuaCode.Value(tree.source, "function(")
        if AST.is_syntax_tree(\%args, "Action") then \%args = \%args:get_args() end
        local lua_args = table.map(\%args, function(a) return AST.is_syntax_tree(a) and tostring(nomsu:compile(a)) or a end)
        lua:concat_append(lua_args, ", ")
        local body_lua = AST.is_syntax_tree(\%body) and nomsu:compile(\%body):as_statements("return ") or \%body
        body_lua:remove_free_vars(lua_args)
        body_lua:declare_locals()
        lua:append(")\\n    ", body_lua, "\\nend")
        return lua
    end

lua> ".."
    nomsu.COMPILE_ACTIONS["compile as %"] = function(nomsu, tree, \%action)
        local lua = LuaCode.Value(tree.source, "nomsu.COMPILE_ACTIONS[", repr(\%action.stub), "](")
        local lua_args = table.map(\%action:get_args(), function(a) return nomsu:compile(a) end)
        table.insert(lua_args, 1, "nomsu")
        table.insert(lua_args, 2, "tree")
        lua:concat_append(lua_args, ", ")
        lua:append(")")
        return lua
    end

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

lua> ".."
    nomsu.COMPILE_ACTIONS["compile % to %"] = function(nomsu, tree, \%actions, \%body)
        local \%args = {"nomsu", "tree", unpack(table.map(\%actions[1]:get_args(), function(a) return tostring(nomsu:compile(a)) end))}
        local lua = LuaCode(tree.source, "nomsu.COMPILE_ACTIONS[", repr(\%actions[1].stub),
            "] = ", \(compile as (%args -> %body)))
        for i=2,#\%actions do
            local alias = \%actions[i]
            local \%alias_args = {"nomsu", "tree", unpack(table.map(alias:get_args(), function(a) return tostring(nomsu:compile(a)) \
    ..end))}
            lua:append("\\nnomsu.COMPILE_ACTIONS[", repr(alias.stub), "] = ")
            if utils.equivalent(\%args, \%alias_args) then
                lua:append("nomsu.COMPILE_ACTIONS[", repr(\%actions[1].stub), "]")
            else
                lua:append("function(")
                lua:concat_append(\%alias_args, ", ")
                lua:append(")\\n    return nomsu.COMPILE_ACTIONS[", repr(\%actions[1].stub), "](")
                lua:concat_append(\%args, ", ")
                lua:append(")\\nend")
            end
        end
        return lua
    end

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

compile [call %fn with %args] to (..)
    lua> ".."
        local lua = LuaCode.Value(tree.source, nomsu:compile(\%fn), "(")
        lua:concat_append(table.map(\%args, function(a) return nomsu:compile(a) end), ", ")
        lua:append(")")
        return lua

compile [local action %actions %body] to (..)
    lua> ".."
        local fn_name = "A"..string.as_lua_id(\%actions[1].stub)
        local \%args = table.map(\%actions[1]:get_args(), function(a) return tostring(nomsu:compile(a)) end)
        local lua = LuaCode(tree.source, fn_name, " = ", \(compile as (%args -> %body)))
        lua:add_free_vars({fn_name})
        for i=2,#\%actions do
            local alias = \%actions[i]
            local alias_name = "A"..string.as_lua_id(alias.stub)
            lua:add_free_vars({alias_name})
            local \%alias_args = table.map(alias:get_args(), function(a) return tostring(nomsu:compile(a)) end)
            lua:append("\\n", alias_name, " = ")
            if utils.equivalent(\%args, \%alias_args) then
                lua:append(fn_name)
            else
                lua:append("function(")
                lua:concat_append(\%alias_args, ", ")
                lua:append(")\\n    return ", fn_name, "(")
                lua:concat_append(\%args, ", ")
                lua:append(")\\nend")
            end
        end
        return lua

compile [action %actions %body] to (..)
    lua> ".."
        local lua = \(compile as (local action %actions %body))
        lua:remove_free_vars(table.map(\%actions, function(a) return "A"..string.as_lua_id(a.stub) end))
        return lua

compile [action %action] to (Lua value "A\(%action.stub as lua id)")
compile [parse %actions as %body] to (..)
    lua> ".."
        local replacements = {}
        for i,arg in ipairs(\%actions[1]:get_args()) do
            replacements[arg[1]] = tostring(nomsu:compile(arg))
        end
        local function make_tree(t)
            if not AST.is_syntax_tree(t) then
                return repr(t)
            elseif t.type ~= 'Var' then
                local args = {repr(tostring(t.source)), unpack(table.map(t, make_tree))}
                return t.type.."("..table.concat(args, ", ")..")"
            elseif replacements[t[1]] then
                return replacements[t[1]]
            else
                return t.type.."("..repr(tostring(t.source))..", "..repr(t[1].." \\0").."..string.format('%X', \
        ..__MANGLE_INDEX))"
            end
        end
        local \%new_body = LuaCode(\%body.source,
            "__MANGLE_INDEX = (__MANGLE_INDEX or 0) + 1",
            "\\nlocal tree = ", make_tree(\%body),
            "\\nlocal lua = nomsu:compile(tree); return lua")
        local ret = \(compile as (compile %actions to %new_body))
        return ret

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

action [%tree as lua expr]:
    lua> ".."
        \%tree_lua = nomsu:compile(\%tree)
        if not \%tree_lua.is_value then
            nomsu:compile_error(\%tree.source, "Could not convert %s to a Lua expression",
                nomsu:tree_to_nomsu(\%tree))
        end
        return \%tree_lua

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

compile [%tree as lua] to (Lua value "nomsu:compile(\(%tree as lua expr))")
compile [%tree as lua statements] to (..)
    Lua value "nomsu:compile(\(%tree as lua expr)):as_statements()"

compile [%tree as lua return] to (..)
    Lua value "nomsu:compile(\(%tree as lua expr)):as_statements('return ')"

compile [remove action %action] to (..)
    Lua "A\(=lua "string.as_lua_id(\(%action.stub))") = nil"

compile [%tree as nomsu] to (..)
    Lua value "nomsu:tree_to_nomsu(\(%tree as lua expr))"

compile [%tree as inline nomsu] to (..)
    Lua value "nomsu:tree_to_nomsu(\(%tree as lua expr), true)"

action [%var as lua identifier, %var as lua id] (..)
    lua> ".."
        if type(\%var) == 'string' then return string.as_lua_id(\%var)
        elseif \%var.type == 'Var' then return string.as_lua_id(\%var[1])
        elseif \%var.type == 'Action' then return "A"..string.as_lua_id(\%var.stub)
        end

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

compile [% is syntax tree] to (Lua value "AST.is_syntax_tree(\(% as lua expr))")
compile [% is %kind syntax tree] to (..)
    Lua value "AST.is_syntax_tree(\(% as lua expr), \(%kind as lua expr))"

compile [%tree with %t -> %replacement] to (..)
    Lua value ".."
        \(%tree as lua expr):map(function(\(%t as lua expr))
            \(%replacement as lua return)
        end)

action [%tree with vars %replacements] (..)
    =lua ".."
        \%tree:map(function(\%t)
            if \%t.type == "Var" then
                return \%replacements[\%t[1]]
            end
        end)

compile [declare locals in %code] to (..)
    Lua value "\(%code as lua expr):declare_locals()"

compile [declare locals %locals in %code] to (..)
    Lua value "\(%code as lua expr):declare_locals(\(%locals as lua expr))"

compile [add free vars %vars to %code] to (..)
    Lua "\(%code as lua expr):add_free_vars(\(%vars as lua expr));"

compile [remove free vars %vars from %code] to (..)
    Lua "\(%code as lua expr):remove_free_vars(\(%vars as lua expr));"

compile [%lua <-write %code, to %lua write %code] to (..)
    Lua "\(%lua as lua expr):append(\(%code as lua expr));"

compile [to %lua write %code joined by %glue] to (..)
    Lua "\(%lua as lua expr):concat_append(\(%code as lua expr), \(%glue as lua expr));"

compile [quote %s] to (Lua value "repr(\(%s as lua expr))")
compile [type of %obj] to (Lua value "type(\(%obj as lua expr))")
compile [parse %text] to (..)
    Lua value "nomsu:parse(NomsuCode(\"\(%text.source)\", \(%text as lua expr)))"

compile [parse %text from %filename] to (..)
    Lua value ".."
        nomsu:parse(NomsuCode(Source(\(%filename as lua expr), 1, #\(%text as lua expr)), \(%text as lua expr)))

compile [run %nomsu_code] to (..)
    Lua value ".."
        nomsu:run(\(%nomsu_code as lua expr), \(=lua "repr(tostring(\(%nomsu_code.source)))"))

action [run tree %tree, %tree as value] (lua> "return nomsu:run(\%tree)")
compile [compile %block, compiled %block, %block compiled] to (..)
    Lua value "nomsu:compile(\(%block as lua))"


# Return statement is wrapped in a do..end block because Lua is unhappy if you
    put code after a return statement, unless you wrap it in a block.
compile [return] to (Lua "do return; end")
compile [return %return_value] to (..)
    Lua "do return \(%return_value as lua expr) end"


# Literals
compile [yes] to (Lua value "true")
compile [no] to (Lua value "false")
compile [nothing, nil, null] to (Lua value "nil")
compile [Nomsu syntax version] to (Lua value "NOMSU_SYNTAX_VERSION")
compile [Nomsu compiler version] to (Lua value "NOMSU_COMPILER_VERSION")
compile [core version] to (Lua value "NOMSU_CORE_VERSION")
compile [lib version] to (Lua value "NOMSU_LIB_VERSION")
compile [command line args] to (Lua value "arg")

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

compile [with local compile actions %body] to (..)
    Lua ".."
        do
            local nomsu = table.fork(nomsu, {COMPILE_ACTIONS=table.fork(nomsu.COMPILE_ACTIONS)})
            \(%body as lua statements)
        end

action [Nomsu version]:
    use "lib/version.nom"
    return ".."
        \(Nomsu syntax version).\(core version).\(Nomsu compiler version).\(lib version)