99 lines
2.8 KiB
Plaintext
99 lines
2.8 KiB
Plaintext
#!/usr/bin/env nomsu -V6.13.12.8
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#
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This file contains basic error reporting code
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use "core/metaprogramming.nom"
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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(barf $msg) compiles to
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"error(\(=lua "\$msg and \($msg as lua expr) or 'nil'"), 0);"
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(assume $condition) compiles to:
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lua> ("
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local \$assumption = 'Assumption failed: '..tostring((\$condition):get_source_code())
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")
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return
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Lua ("
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if not \($condition as lua expr) then
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error(\(quote "\$assumption"), 0)
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end
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")
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(assume $a == $b) compiles to:
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lua> "local \$assumption = 'Assumption failed: '..tostring(\(\($a == $b) as nomsu))"
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define mangler
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return
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Lua ("
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do
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local \(mangle "a"), \(mangle "b") = \($a as lua expr), \($b as lua expr)
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if \(mangle "a") ~= \(mangle "b") then
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error(\(quote "\$assumption").."\\n"..tostring(\(mangle "a")).." != "..tostring(\
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..\(mangle "b")), 0)
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end
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end
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")
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(assume $condition or barf $message) compiles to ("
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if not \($condition as lua expr) then
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error(\($message as lua expr), 0)
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end
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")
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test:
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try (barf) and if it succeeds:
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barf "try failed."
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$worked = (no)
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try (barf) and if it barfs:
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$worked = (yes)
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assume $worked or barf "try/catch failed"
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$x = 1
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try:
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$x = 2
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do (barf) then always: $x = 3
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..and if it barfs:
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do nothing
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assume ($x == 3) or barf "do/then always failed"
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# Try/except
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[
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try $action and if it succeeds $success or if it barfs $msg $fallback
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try $action and if it barfs $msg $fallback or if it succeeds $success
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] all compile to ("
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do
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local fell_through = false
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local err, erred = nil, false
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local ok, ret = xpcall(function()
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\($action as lua)
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fell_through = true
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end, function(\(=lua "\$fallback and \($msg as lua expr) or ''"))
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local ok, ret = pcall(function()
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\((=lua "\$fallback or \$msg") as lua)
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end)
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if not ok then err, erred = ret, true end
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end)
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if ok then
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\($success as lua)
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if not fell_through then
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return ret
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end
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elseif erred then
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error(err, 0)
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end
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end
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")
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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(try $action) parses as
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try $action and if it succeeds (do nothing) or if it barfs (do nothing)
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(try $action and if it barfs $msg $fallback) parses as
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try $action and if it succeeds (do nothing) or if it barfs $msg $fallback
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(try $action and if it succeeds $success) parses as
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try $action and if it succeeds $success or if it barfs (do nothing)
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