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Diffstat (limited to 'engine/evarutil.ml')
| -rw-r--r-- | engine/evarutil.ml | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/engine/evarutil.ml b/engine/evarutil.ml index 50c5b354e..13444cb37 100644 --- a/engine/evarutil.ml +++ b/engine/evarutil.ml @@ -667,6 +667,28 @@ let gather_dependent_evars evm l = (* /spiwack *) +(** [advance sigma g] returns [Some g'] if [g'] is undefined and is + the current avatar of [g] (for instance [g] was changed by [clear] + into [g']). It returns [None] if [g] has been (partially) + solved. *) +(* spiwack: [advance] is probably performance critical, and the good + behaviour of its definition may depend sensitively to the actual + definition of [Evd.find]. Currently, [Evd.find] starts looking for + a value in the heap of undefined variable, which is small. Hence in + the most common case, where [advance] is applied to an unsolved + goal ([advance] is used to figure if a side effect has modified the + goal) it terminates quickly. *) +let rec advance sigma evk = + let evi = Evd.find sigma evk in + match evi.evar_body with + | Evar_empty -> Some evk + | Evar_defined v -> + if Option.default false (Store.get evi.evar_extra cleared) then + let (evk,_) = Term.destEvar v in + advance sigma evk + else + None + (** The following functions return the set of undefined evars contained in the object, the defined evars being traversed. This is roughly a combination of the previous functions and |