43 lines
1.2 KiB
Lua
43 lines
1.2 KiB
Lua
-- Copyright (c) 2006-2013 Fabien Fleutot and others.
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--
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-- All rights reserved.
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checkers = { }
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local function check_one(expected, val)
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if type(val)==expected then return true end
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local mt = getmetatable(val)
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if mt and mt.__type==expected then return true end
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local f = checkers[expected]
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if f and f(val) then return true end
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return false
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end
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local function check_many(_, expected, val)
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if expected=='?' then return true
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elseif expected=='!' then return (val~=nil)
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elseif type(expected) ~= 'string' then
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error 'strings expected by checks()'
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elseif val==nil and expected :sub(1,1) == '?' then return true end
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for one in expected :gmatch "[^|?]+" do
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if check_one(one, val) then return true end
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end
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return false
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end
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local function checks(...)
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for i, arg in ipairs{...} do
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local name, val = debug.getlocal(2, i)
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local success = check_many(name, arg, val)
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if not success then
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local fname = debug.getinfo(2, 'n').name
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local fmt = "bad argument #%d to '%s' (%s expected, got %s)"
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local msg = string.format(fmt, i, fname or "?", arg, type(val))
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error(msg, 3)
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end
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end
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end
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return checks
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