1Local_store(3)                   OCaml library                  Local_store(3)
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NAME

6       Local_store  - This module provides some facilities for creating refer‐
7       ences (and hash tables) which can easily be snapshoted and restored  to
8       an arbitrary version.
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Module

11       Module   Local_store
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Documentation

14       Module Local_store
15        : sig end
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18       This  module provides some facilities for creating references (and hash
19       tables) which can easily be snapshoted and  restored  to  an  arbitrary
20       version.
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22       It is used throughout the frontend (read: typechecker), to register all
23       (well, hopefully) the global state. Thus making it easy for tools  like
24       Merlin to go back and forth typechecking different files.
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32   Creators
33       val s_ref : 'a -> 'a ref
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35       Similar  to ref , except the allocated reference is registered into the
36       store.
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40       val s_table : ('a -> 'b) -> 'a -> 'b ref
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42       Used to register hash tables. Those also need to be placed into refs to
43       be  easily swapped out, but one can't just "snapshot" the initial value
44       to create fresh instances, so instead an initializer is required.
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46       Use it like this:
47             let my_table = s_table Hashtbl.create 42
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53   State management
54       Note: all the following functions are currently unused inside the  com‐
55       piler codebase. Merlin is their only user at the moment.
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57       type store
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63       val fresh : unit -> store
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65       Returns a fresh instance of the store.
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67       The  first  time this function is called, it snapshots the value of all
68       the registered references, later calls to fresh will  return  instances
69       initialized to those values.
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73       val with_store : store -> (unit -> 'a) -> 'a
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76       with_scope  s  f resets all the registered references to the value they
77       have in s for the run of f .  If f updates any of the registered  refs,
78       s is updated to remember those changes.
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82       val reset : unit -> unit
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84       Resets  all  the  references  to the initial snapshot (i.e. to the same
85       values that new instances start with).
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89       val is_bound : unit -> bool
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91       Returns true when a scope is active (i.e. when called from the callback
92       passed to with_scope ), false otherwise.
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98OCamldoc                          2021-07-22                    Local_store(3)