samples/match_test.mlua

-------------------------------------------------------------------------------
-- Copyright (c) 2006-2013 Fabien Fleutot and others.
--
-- All rights reserved.
--
-- This program and the accompanying materials are made available
-- under the terms of the Eclipse Public License v1.0 which
-- accompanies this distribution, and is available at
-- http://www.eclipse.org/legal/epl-v10.html
--
-- This program and the accompanying materials are also made available
-- under the terms of the MIT public license which accompanies this
-- distribution, and is available at http://www.lua.org/license.html
--
-- Contributors:
--     Fabien Fleutot - API and implementation
--
-------------------------------------------------------------------------------

-{extension 'match'}

WIDTH = 50
function p(msg)
   io.write(msg, ' ':rep(WIDTH-#msg))
   io.flush()
end

p "Basic match"
match 1 with 1 -> print 'ok' end

p "Sequence match"
match 3, 4 with 
| 1, 2 -> print 'KO'
| 3, 4 -> print 'ok' 
end

p "Id binding"
match 3, 4 with 
| 1, 2 -> print 'KO'
| x, y -> print 'ok' 
end

p "Table destructuring & non-litteral tested term"
match {1, 2} with
|{a, 2} -> assert(a==1); print 'ok'
end

p "Pattern group"
match {'?'} with
|1|2|3 -> print 'KO'
|{...} -> print 'ok'
end

p "Multi-level destructuring"
match {{1000}} with
|{{2000}} -> print 'KO'
|{{3000}} -> print 'KO'
|{{1000}} -> print 'ok'
end

p "Guard"
match 1 with
| 1 if false -> print 'KO'
| 1 -> print 'ok'
end

p "Guard with bound var"
match 1 with
| a if a ~= 1 -> print 'KO'
| a if a == 1 -> print 'ok'
end

p "Non linear var & destructuring"
match {1, {2}} with
| {a, {a}} -> print 'KO'
| {a, {b}} -> print 'ok'
end

p "Non-linear vars on a sequence"
match 1, 2 with
| a, a -> print 'KO'
| a, b -> print 'ok'
end

p "Multiple _ wildcards"
match 1, 2 with
| _, _ -> print 'ok'
| a, b -> print 'KO'
end

p "Regexp & non-linear vars"
match 'toto' with
| 't(.)t(.)' / { a, a } -> print (a..'k')
end

p "Nested match & ..."
match { { 'o', 'k', '!' } } with
| { t } -> match t with
   | { a, b }      -> print 'KO'
   | { a, b, ... } -> print (a..b)
   | _             -> print 'KO'
   end
| _ -> print 'KO'
end