lean4-htt/src/extra/parse_lean_tpl.lua
Leonardo de Moura 20c6789d1c feat(extra): add extension that demonstrates how to parse 'templates'
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-11-19 15:56:44 -08:00

54 lines
1.7 KiB
Lua

-- Parse a template expression string 'str'.
-- The string 'str' contains placeholders of the form 'a::i', where 'i' is a numeral.
-- The placeholders are replaced with values from the array 'args'.
-- See 'test' function for an example.
function parse_lean_tpl(str, args, env, opts, fmt)
assert(type(str) == "string")
assert(type(args) == "table")
assert(env == nil or is_environment(env))
if #args == 0 then
return parse_lean(str, env, opts, fmt)
else
-- Create the string "fun (a::1 : type-of-args[1]) ... (a::n : type-of-args[n]), $str",
-- where n is the size of args
local inferer = type_inferer(env)
local tbl = {"fun"}
for i = 1, #args do
table.insert(tbl, " (a::")
table.insert(tbl, i)
table.insert(tbl, " : ")
table.insert(tbl, tostring(inferer(args[i])))
table.insert(tbl, ")")
end
table.insert(tbl, ", ")
table.insert(tbl, str)
local new_str = table.concat(tbl)
local r = parse_lean(new_str, env, opts, fmt)
for i = 1, #args do
assert(r:is_lambda())
local n, d, body = r:fields()
r = body:instantiate(args[i])
end
return r
end
end
local test = function()
local env = environment()
-- Load environment with some definitions
parse_lean_cmds([[
Variables a b : Real
Variable f : Real -> Real
Variable g : Real -> Real -> Real
]], env)
local a, b, g = Consts("a, b, g")
local t1 = parse_lean_tpl("a::1 + (f a::2) - 10 + a::2", {a, g(b, a)}, env)
print(t1)
local t2 = parse_lean_tpl("f (a::1 + 1)", {g(b, b)}, env)
print(t2)
end
if not pcall(debug.getlocal, 4, 1) then
-- Main file
test()
end