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26 lines
741 B
Idris
26 lines
741 B
Idris
module Issue2712
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-- a non-dependent indexed state monad, à la TDD Ch 13+14
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data ISM : Type -> Nat -> Nat -> Type where
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CMD_INIT : (n : Nat) -> ISM () n n
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CMD_INCR : ISM () n (S n)
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Pure : (x : t) -> ISM t n n
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(>>=) : ISM a from to
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-> ISM b to to2
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-> ISM b from to2
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-- this should be considered covering
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foo : ISM a st st -> () -- note the fixed 'to' and 'from' state
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foo (CMD_INIT n) = ?foo_rhs_0
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foo (Pure x) = ?foo_rhs_2
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foo (x >>= f) = ?foo_rhs_3
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failing "Cycle detected in solution of metavariable"
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foo' : ISM a st st -> () -- note the fixed 'to' and 'from' state
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foo' (CMD_INIT n) = ?foo_bis_rhs_0
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foo' CMD_INCR = ?foo_bis_rhs_1
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foo' (Pure x) = ?foo_bis_rhs_2
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foo' (x >>= f) = ?foo_bis_rhs_3
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