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#!/usr/bin/env nomsu -V2.2.4.3
#
This file contains basic error reporting code
use "core/metaprogramming.nom"
compile [traceback] to (Lua value "debug.traceback()")
compile [traceback %] to (Lua value "debug.traceback('', \(% as lua expr))")
compile [barf] to (Lua "error(nil, 0);")
compile [barf %msg] to (Lua "error(\(%msg as lua expr), 0);")
compile [assume %condition] to:
lua> ".."
local \%assumption = 'Assumption failed: '..tostring(nomsu:tree_to_nomsu(\%condition))
return (..)
Lua ".."
if not \(%condition as lua expr) then
error(\(quote "\%assumption"), 0)
end
compile [assume %condition or barf %message] to (..)
Lua ".."
if not \(%condition as lua expr) then
error(\(%message as lua expr), 0)
end
# Try/except
compile [..]
try %action and if it succeeds %success or if it barfs %msg %fallback
try %action and if it barfs %msg %fallback or if it succeeds %success
..to (..)
Lua ".."
do
local fell_through = false
local err, erred = nil, false
local ok, ret = xpcall(function()
\(%action as lua statements)
fell_through = true
end, function(\(%msg as lua expr))
local ok, ret = pcall(function()
\(%fallback as lua statements)
end)
if not ok then err, erred = ret, true end
end)
if ok then
\(%success as lua statements)
if not fell_through then
return ret
end
elseif erred then
error(err, 0)
end
end
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
parse [..]
try %action and if it succeeds %success or if it barfs %fallback
try %action and if it barfs %fallback or if it succeeds %success
..as (try %action and if it succeeds %success or if it barfs (=lua "") %fallback)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
parse [try %action] as (..)
try %action and if it succeeds (do nothing) or if it barfs (do nothing)
parse [try %action and if it barfs %fallback] as (..)
try %action and if it succeeds (do nothing) or if it barfs %fallback
parse [try %action and if it barfs %msg %fallback] as (..)
try %action and if it succeeds (do nothing) or if it barfs %msg %fallback
parse [try %action and if it succeeds %success] as (..)
try %action and if it succeeds %success or if it barfs (do nothing)
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