package lustre-v6

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Sub module of EvalClock that defines clock-checking utilities.

We have Two kind of substitutions.

  • subst1 is used to deal with the clock name binding, to relate node parameters and node arguments (to check clock equality up to alpha conversion).
  • subst2 is used to deal with polymorphic clock variables. Indeed, constant clock is intrinsically polymorphic. Hence, when clocking a contant (e.g., "42"), we return the clock_info Ci_var i, where i is a fresh integer. Afterwards, when encoutering an expression such as "42+x", where we know the clock of x (clk_x), we produce the substitution (i,clk_x).

XXX Shouldn't I merge the 2 kind of substitutions ? That would mean I need to invent a fake var_info_eff, but it would make the whole more homogeous.

XXX Make subst abstract?

type subst1 = (Lv6Id.t * Lv6Id.t) list
type subst2
type subst = subst1 * subst2
val empty_subst : subst
val subst_to_string : subst -> string
val apply_subst : subst -> Lic.clock -> Lic.clock
val apply_subst2 : subst -> Lic.clock -> Lic.clock
val add_subst2 : int -> Lic.clock -> subst2 -> subst2
val add_link2 : int -> int -> subst2 -> subst2
val apply_subst_val_exp : subst -> Lic.val_exp -> Lic.val_exp
val f : subst -> Lxm.t -> Lic.clock -> Lic.clock -> subst

f lxm s clk_arg clk_par Raises a Compile_error is the 2 Lic.clock clk_arg and clk_par are not compatible. The accumulated substitution s is augmented with eventual clock variable instanciation.

For instance, when clock checking the expression 'toto(a,b)', if toto has the clock profile "alpha x alpha -> alpha", and the args 'a' and 'b' are on clock 'clk', the expression 'toto(a,b)' should be on clk too. We can check that later using the association "alpha->clk" is added in the returned substitution.

XXX UnifyClock.f is not a good name actually. CheckClock.f would better reflect the reality

val list : Lxm.t list -> Lic.clock list -> subst -> subst
val new_clock_var : subst -> subst * Lic.clock
val const_to_val_eff : Lxm.t -> bool -> subst -> Lic.const -> subst * Lic.val_exp

Transform a const into a val_exp const_to_val_eff lxm flag s const

  • flag tells if abstract const should be expanded
  • s is used to provide a clock to val_exp (actually, this is why this function is in this module, but it's a weird reason).

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