The Coq Proof Assistant

# Library Ltac2.Control

Require Import Ltac2.Init.
Require Ltac2.Message.
Panic
Ltac2 @ external throw : exn -> 'a := "ltac2" "throw".
Fatal exception throwing. This does not induce backtracking.
Generic backtracking control
Ltac2 @ external zero : exn -> 'a := "ltac2" "zero".
Ltac2 @ external plus : (unit -> 'a) -> (exn -> 'a) -> 'a := "ltac2" "plus".
Ltac2 @ external once : (unit -> 'a) -> 'a := "ltac2" "once".
Ltac2 @ external dispatch : (unit -> unit) list -> unit := "ltac2" "dispatch".
Ltac2 @ external extend : (unit -> unit) list -> (unit -> unit) -> (unit -> unit) list -> unit := "ltac2" "extend".
Ltac2 @ external enter : (unit -> unit) -> unit := "ltac2" "enter".
Ltac2 @ external case : (unit -> 'a) -> ('a * (exn -> 'a)) result := "ltac2" "case".
Proof state manipulation
Ltac2 @ external focus : int -> int -> (unit -> 'a) -> 'a := "ltac2" "focus".
Ltac2 @ external shelve : unit -> unit := "ltac2" "shelve".
Ltac2 @ external shelve_unifiable : unit -> unit := "ltac2" "shelve_unifiable".
Ltac2 @ external new_goal : evar -> unit := "ltac2" "new_goal".
Adds the given evar to the list of goals as the last one. If it is already defined in the current state, don't do anything. Panics if the evar is not in the current state.
Ltac2 @ external progress : (unit -> 'a) -> 'a := "ltac2" "progress".
Goal inspection
Ltac2 @ external goal : unit -> constr := "ltac2" "goal".
Panics if there is not exactly one goal under focus. Otherwise returns the conclusion of this goal.
Ltac2 @ external hyp : ident -> constr := "ltac2" "hyp".
Panics if there is more than one goal under focus. If there is no goal under focus, looks for the section variable with the given name. If there is one, looks for the hypothesis with the given name.
Ltac2 @ external hyps : unit -> (ident * constr option * constr) list := "ltac2" "hyps".
Panics if there is more than one goal under focus. If there is no goal under focus, returns the list of section variables. If there is one, returns the list of hypotheses. In both cases, the list is ordered with rightmost values being last introduced.
Refinement
Ltac2 @ external refine : (unit -> constr) -> unit := "ltac2" "refine".
Evars
Ltac2 @ external with_holes : (unit -> 'a) -> ('a -> 'b) -> 'b := "ltac2" "with_holes".
with_holes x f evaluates x, then apply f to the result, and fails if all evars generated by the call to x have not been solved when f returns.
Misc
Ltac2 @ external time : string option -> (unit -> 'a) -> 'a := "ltac2" "time".
Displays the time taken by a tactic to evaluate.
Ltac2 @ external abstract : ident option -> (unit -> unit) -> unit := "ltac2" "abstract".
Abstract a subgoal.
Ltac2 @ external check_interrupt : unit -> unit := "ltac2" "check_interrupt".
For internal use.
Assertions throwing exceptions and short form throws
Ltac2 throw_invalid_argument (msg : string) :=
Control.throw (Invalid_argument (Some (Message.of_string msg))).
Ltac2 throw_out_of_bounds (msg : string) :=
Control.throw (Out_of_bounds (Some (Message.of_string msg))).
Ltac2 assert_valid_argument (msg : string) (test : bool) :=
match test with
| true => ()
| false => throw_invalid_argument msg
end.
Ltac2 assert_bounds (msg : string) (test : bool) :=
match test with
| true => ()
| false => throw_out_of_bounds msg
end.
Ltac2 assert_true b :=
if b then () else throw Assertion_failure.
Ltac2 assert_false b :=
if b then throw Assertion_failure else ().
Short form backtracks
Ltac2 backtrack_tactic_failure (msg : string) :=
Control.zero (Tactic_failure (Some (Message.of_string msg))).