1 --------------------------------------------------------------------------------
3 -- Non-Lua syntax extensions
5 --------------------------------------------------------------------------------
7 module ("mlp", package.seeall)
9 --------------------------------------------------------------------------------
11 --------------------------------------------------------------------------------
12 local function adt (lx)
13 local tagval = id (lx) [1]
14 local tagkey = {tag="Key", {tag="String", "tag"}, {tag="String", tagval} }
15 if lx:peek().tag == "String" or lx:peek().tag == "Number" then
16 return { tag="Table", tagkey, lx:next() }
17 elseif lx:is_keyword (lx:peek(), "{") then
19 _G.table.insert (x, 1, tagkey)
21 else return { tag="Table", tagkey } end
24 expr:add{ "`", adt, builder = fget(1) }
26 --------------------------------------------------------------------------------
28 --------------------------------------------------------------------------------
29 local lambda_expr = gg.sequence{
30 "|", func_params_content, "|", expr,
32 return {tag="Function", x[1], { {tag="Return", x[2] } } } end }
34 -- In an earlier version, lambda_expr took an expr_list rather than an expr
35 -- after the 2nd bar. However, it happened to be much more of a burden than an
36 -- help, So finally I disabled it. If you want to return several results,
37 -- use the long syntax.
38 --------------------------------------------------------------------------------
39 -- local lambda_expr = gg.sequence{
40 -- "|", func_params_content, "|", expr_list,
41 -- builder= function (x)
42 -- return {tag="Function", x[1], { {tag="Return", unpack(x[2]) } } } end }
44 expr:add (lambda_expr)
46 --------------------------------------------------------------------------------
47 -- Allows to write "a `f` b" instead of "f(a, b)". Taken from Haskell.
48 -- This is not part of Lua 5.1 syntax, so it's added to the expression
49 -- afterwards, so that it's easier to disable.
50 --------------------------------------------------------------------------------
51 local function expr_in_backquotes (lx) return expr(lx, 35) end
53 expr.infix:add{ name = "infix function",
54 "`", expr_in_backquotes, "`", prec = 35, assoc="left",
55 builder = function(a, op, b) return {tag="Call", op[1], a, b} end }
58 --------------------------------------------------------------------------------
59 -- table.override assignment
60 --------------------------------------------------------------------------------
63 stat.assignments["<-"] = function (a, b)
64 assert( #a==1 and #b==1, "No multi-args for '<-'")
65 return { tag="Call", { tag="Index", { tag="Id", "table" },
66 { tag="String", "override" } },
70 --------------------------------------------------------------------------------
71 -- C-style op+assignments
72 --------------------------------------------------------------------------------
73 local function op_assign(kw, op)
74 local function rhs(a, b)
75 return { tag="Op", op, a, b }
78 return { tag="Let", a, _G.table.imap(rhs, a, b) }
81 mlp.stat.assignments[kw] = f
84 _G.table.iforeach (op_assign,
85 {"+=", "-=", "*=", "/="},
86 {"add", "sub", "mul", "div"})