Changes between Coq 8.8 and Coq 8.9

ML API

Names

In Libnames, the type reference and its two constructors Qualid and Ident have been removed in favor of qualid. Qualid is now the identity, Ident can be replaced by qualid_of_ident. Matching over reference can be replaced by a test using qualid_is_ident. Extracting the ident part of a qualid can be done using qualid_basename.

Misctypes

Syntax for universe sorts and kinds has been moved from Misctypes to Glob_term, as these are turned into kernel terms by Pretyping.

Proof engine

More functions have been changed to use EConstr, notably the functions in Evd, and in particular Evd.define.

Note that the core function EConstr.to_constr now enforces by default that the resulting term is ground, that is to say, free of Evars. This is usually what you want, as open terms should be of type EConstr.t to benefit from the invariants the EConstr API is meant to guarantee.

In case you'd like to violate this API invariant, you can use the abort_on_undefined_evars flag to EConstr.to_constr, but note that setting this flag to false is deprecated so it is only meant to be used as to help port pre-EConstr code.
A few type alias have been deprecated, in all cases the message should indicate what the canonical form is. An important change is the move of Globnames.global_reference to Names.GlobRef.t.
Unification API returns evar_map option instead of bool * evar_map with the guarantee that the evar_map was unchanged if the boolean was false.

ML Libraries used by Coq

Introduction of a "Smart" module for collecting "smart*" functions, e.g. Array.Smart.map.
Uniformization of some names, e.g. Array.Smart.fold_left_map instead of Array.smartfoldmap.

Printer.ml API

The mechanism in Printer that allowed dynamically overriding pr_subgoals, pr_subgoal and pr_goal was removed to simplify the code. It was earlierly used by PCoq.

Source code organization

We have eliminated / fused some redundant modules and relocated a few interfaces files. The intf folder is gone, and now for example Constrexpr is located in interp/, Vernacexpr in vernac/ and so on. Changes should be compatible, but in a few cases stricter layering requirements may mean that functions have moved. In all cases adapting is a matter of changing the module name.

Vernacular commands

The implementation of vernacular commands has been refactored so it is self-contained now, including the parsing and extension mechanisms. This involves a couple of non-backward compatible changes due to layering issues, where some functions have been moved from Pcoq to Pvernac and from Vernacexpr to modules in tactics/. In all cases adapting is a matter of changing the module name.

Unit testing

The test suite now allows writing unit tests against OCaml code in the Coq code base. Those unit tests create a dependency on the OUnit test framework.

Changes between Coq 8.7 and Coq 8.8

Bug tracker

As of 18/10/2017, Coq uses GitHub issues as bug tracker. Old bug reports were migrated from Bugzilla to GitHub issues using this migration script as detailed in this blog post.

All the bugs with a number below 1154 had to be renumbered, you can find a correspondence table here. All the other bugs kept their number.

ML API

General deprecation

All functions marked [@@ocaml.deprecated] in 8.7 have been removed. Please, make sure your plugin is warning-free in 8.7 before trying to port it over 8.8.

Proof engine

Due to the introduction of EConstr in 8.7, it is not necessary to track "goal evar normal form status" anymore, thus the type 'a Proofview.Goal.t loses its ghost argument. This may introduce some minor incompatibilities at the typing level. Code-wise, things should remain the same.

We removed the following functions:

Universes.unsafe_constr_of_global: use Global.constr_of_global_in_context instead. The returned term contains De Bruijn universe variables. If you don't depend on universes being instantiated, simply drop the context.
Universes.unsafe_type_of_global: same as above with Global.type_of_global_in_context

We changed the type of the following functions:

Global.body_of_constant_body: now also returns the abstract universe context. The returned term contains De Bruijn universe variables.
Global.body_of_constant: same as above.
Constrinterp.* generally, many functions that used to take an evar_map ref have been now switched to functions that will work in a functional way. The old style of passing evar_maps as references is not supported anymore.

Changes in the abstract syntax tree:

The practical totality of the AST has been nodified using CAst.t. This means that all objects coming from parsing will be indeed wrapped in a CAst.t. Loc.located is on its way to deprecation. Some minor interfaces changes have resulted from this.

We have changed the representation of the following types:

Lib.object_prefix is now a record instead of a nested tuple.

Some tactics and related functions now support static configurability, e.g.:

injectable, dEq, etc. takes an argument ~keep_proofs which,
- if None, tells to behave as told with the flag Keep Proof Equalities
- if Some b, tells to keep proof equalities iff b is true

Declaration of printers for arguments used only in vernac command

It should now use "declare_extra_vernac_genarg_pprule" rather than "declare_extra_genarg_pprule", otherwise, a failure at runtime might happen. An alternative is to register the corresponding argument as a value, using "Geninterp.register_val0 wit None".

Types Alias deprecation and type relocation.

A few type alias have been deprecated, in all cases the message should indicate what the canonical form is.

STM API

The STM API has seen a general overhaul. The main change is the introduction of a "Coq document" type, which all operations now take as a parameter. This effectively functionalize the STM API and will allow in the future to handle several documents simultaneously.

The main remarkable point is that key implicit global parameters such as load-paths and required modules are now arguments to the document creation function. This helps enforcing some key invariants.

XML IDE Protocol

Before 8.8, Query only executed the first command present in the query string; starting with 8.8, the caller may include several statements. This is useful for instance for temporarily setting an option and then executing a command.

Changes between Coq 8.6 and Coq 8.7

Ocaml

Coq is compiled with -safe-string enabled and requires plugins to do the same. This means that code using String in an imperative way will fail to compile now. They should switch to Bytes.t

Configure supports passing flambda options, use -flambda-opts OPTS with a flambda-enabled Ocaml to tweak the compilation to your taste.

ML API

Added two functions for declaring hooks to be executed in reduction functions when some given constants are traversed:
- declare_reduction_effect: to declare a hook to be applied when some constant are visited during the execution of some reduction functions (primarily cbv).
- set_reduction_effect: to declare a constant on which a given effect hook should be called.

We renamed the following functions:

Context.Rel.Declaration.fold   -> Context.Rel.Declaration.fold_constr
Context.Named.Declaration.fold -> Context.Named.Declaration.fold_constr
Printer.pr_var_list_decl       -> Printer.pr_compacted_decl
Printer.pr_var_decl            -> Printer.pr_named_decl
Nameops.lift_subscript         -> Nameops.increment_subscript

We removed the following functions:
- Termops.compact_named_context_reverse: practical substitute is Termops.compact_named_context.
- Namegen.to_avoid: equivalent substitute is Names.Id.List.mem.
We renamed the following modules:
- Context.ListNamed -> Context.Compacted
The following type aliases where removed
- Context.section_context: it was just an alias for Context.Named.t which is still available.
The module Constrarg was merged into Stdarg.
The following types have been moved and modified:
- local_binder -> local_binder_expr
- glob_binder merged with glob_decl

The following constructors have been renamed:

LocalRawDef -> CLocalDef
LocalRawAssum -> CLocalAssum
LocalPattern -> CLocalPattern

In Constrexpr_ops:

Deprecating abstract_constr_expr in favor of mkCLambdaN, and prod_constr_expr in favor of mkCProdN. Note: the first ones were interpreting (x y z:_) as (x:_) (y:_) (z:_) while the second ones were preserving the original sharing of the type.
In Nameops:

The API has been made more uniform. New combinators added in the Name space name. Function out_name now fails with IsAnonymous rather than with Failure "Nameops.out_name".
Location handling and AST attributes:

Location handling has been reworked. First, Loc.ghost has been removed in favor of an option type, all objects carrying an optional source code location have been switched to use Loc.t option.

Storage of location information has been also refactored. The main datatypes representing Coq AST (constrexpr, glob_expr) have been switched to a generic "node with attributes" representation 'a CAst.ast, which is a record of the form:
```
type 'a ast = private {
  v   : 'a;
  loc : Loc.t option;
  ...
}
```
consumers of AST nodes are recommended to use accessor-based pattern matching { v; loc } to destruct ast object. Creation is done with CAst.make ?loc obj, where the attributes are optional. Some convenient combinators are provided in the module. A typical match:
```
| CCase(loc, a1) -> CCase(loc, f a1)
```
is now done as:
```
| { v = CCase(a1); loc } -> CAst.make ?loc @@ CCase(f a1)
```
or even better, if plan to preserve the attributes you can wrap your top-level function in CAst.map to have:
```
| CCase(a1) -> CCase(f a1)
```
This scheme based on records enables easy extensibility of the AST node type without breaking compatibility.

Not all objects carrying a location have been converted to the generic node representation, some of them may be converted in the future, for some others the abstraction is not just worth it.

Thus, we still maintain a 'a Loc.located == Loc.t option * a', tuple type which should be treated as private datatype (ok to match against, but forbidden to manually build), and it is mandatory to use it for objects that carry a location. This policy has been implemented in the whole code base. Matching a located object hasn't changed, however, Loc.tag ?loc obj must be used to build one.
In GOption:

Support for non-synchronous options has been removed. Now all options are handled as a piece of normal document state, and thus passed to workers, etc... As a consequence, the field Goptions.optsync has been removed.
In Coqlib / reference location:

We have removed from Coqlib functions returning constr from names. Now it is only possible to obtain references, that must be processed wrt the particular needs of the client. We have changed in constrintern the functions returnin constr as well to return global references instead.

Users of coq_constant/gen_constant can do Universes.constr_of_global (find_reference dir r) however note the warnings in the Universes.constr_of_global in the documentation. It is very likely that you were previously suffering from problems with polymorphic universes due to using Coqlib.coq_constant that used to do this. You must rather use pf_constr_of_global in tactics and Evarutil.new_global variants when constructing terms in ML (see univpoly.txt for more information).

Tactic API

pf_constr_of_global now returns a tactic instead of taking a continuation. Thus it only generates one instance of the global reference, and it is the caller's responsibility to perform a focus on the goal.
pf_global, construct_reference, global_reference, global_reference_in_absolute_module now return a global_reference instead of a constr.
The tclWEAK_PROGRESS and tclNOTSAMEGOAL tacticals were removed. Their usecase was very specific. Use tclPROGRESS instead.
New (internal) tactical tclINDEPENDENTL that combined with enter_one allows to iterate a non-unit tactic on all goals and access their returned values.
The unsafe flag of the Refine.refine function and its variants has been renamed and dualized into typecheck and has been made mandatory.

Ltac API

Many Ltac specific API has been moved in its own ltac/ folder. Amongst other important things:

Pcoq.Tactic -> Pltac
Constrarg.wit_tactic -> Tacarg.wit_tactic
Constrarg.wit_ltac -> Tacarg.wit_ltac
API below ltac/ that accepted a *_tactic_expr now accept a *_generic_argument instead
Some printing functions were moved from Pptactic to Pputils
A part of Tacexpr has been moved to Tactypes
The TacFun tactic expression constructor now takes a Name.t list for the variable list rather than an Id.t option list.

The folder itself has been turned into a plugin. This does not change much, but because it is a packed plugin, it may wreak havoc for third-party plugins depending on any module defined in the ltac/ directory. Namely, even if everything looks OK at compile time, a plugin can fail to load at link time because it mistakenly looks for a module Foo instead of Ltac_plugin.Foo, with an error of the form:

Error: while loading myplugin.cmxs, no implementation available for Foo.

In particular, most EXTEND macros will trigger this problem even if they seemingly do not use any Ltac module, as their expansion do.

The solution is simple, and consists in adding a statement open Ltac_plugin in each file using a Ltac module, before such a module is actually called. An alternative solution would be to fully qualify Ltac modules, e.g. turning any call to Tacinterp into Ltac_plugin.Tacinterp. Note that this solution does not work for EXTEND macros though.

Additional changes in tactic extensions

Entry constr_with_bindings has been renamed into open_constr_with_bindings. New entry constr_with_bindings now uses type classes and rejects terms with unresolved holes.

Error handling

All error functions now take an optional parameter ?loc:Loc.t. For functions that used to carry a suffix _loc, such suffix has been dropped.
errorlabstrm and error has been removed in favor of user_err.
The header parameter to user_err has been made optional.

Pretty printing

Some functions have been removed, see pretty printing below for more details.

Pretty Printing and XML protocol

The type std_cmdpps has been reworked and made the canonical "Coq rich document type". This allows for a more uniform handling of printing (specially in IDEs). The main consequences are:

Richpp has been confined to IDE use. Most of previous uses of the richpp type should be replaced now by Pp.std_cmdpps. Main API has been updated.
The XML protocol will send a new message type of pp, which should be rendered client-wise.
Set Printing Width is deprecated, now width is controlled client-side.
Pp_control has removed. The new module Topfmt implements console control for the toplevel.
The impure tag system in Pp has been removed. This also does away with the printer signatures and functors. Now printers tag unconditionally.

The following functions have been removed from Pp:

val stras : int * string -> std_ppcmds
val tbrk  : int * int -> std_ppcmds
val tab   : unit -> std_ppcmds
val pifb  : unit -> std_ppcmds
val comment  : int -> std_ppcmds
val comments : ((int * int) * string) list ref
val eval_ppcmds : std_ppcmds -> std_ppcmds
val is_empty : std_ppcmds -> bool
val t : std_ppcmds -> std_ppcmds
val hb : int -> std_ppcmds
val vb : int -> std_ppcmds
val hvb : int -> std_ppcmds
val hovb : int -> std_ppcmds
val tb : unit -> std_ppcmds
val close : unit -> std_ppcmds
val tclose : unit -> std_ppcmds
val open_tag : Tag.t -> std_ppcmds
val close_tag : unit -> std_ppcmds
val msg_with  : ...

module Tag

Stm API

We have streamlined the Stm API, now add and query take a coq_parsable instead a string so clients can have more control over their input stream. As a consequence, their types have been modified.
The main parsing entry point has also been moved to the Stm. Parsing is considered a synchronous operation so it will either succeed or raise an exception.
Feedback is now only emitted for asynchronous operations. As a consequence, it always carries a valid stateid and the type has changed to accommodate that.
A few unused hooks were removed due to cleanups, no clients known.

Toplevel and Vernacular API

The components related to vernacular interpretation have been moved to their own folder vernac/ whereas toplevel now contains the proper toplevel shell and compiler.
Coq's toplevel has been ported to directly use the common Stm API. The signature of a few functions has changed as a result.

XML Protocol

The legacy Interp call has been turned into a noop.
The query call has been modified, now it carries a mandatory route_id integer parameter, that associated the result of such query with its generated feedback.

Changes between Coq 8.5 and Coq 8.6

Parsing

Pcoq.parsable now takes an extra optional filename argument so as to bind locations to a file name when relevant.

Files

To avoid clashes with OCaml's compiler libs, the following files were renamed:

kernel/closure.ml{,i} -> kernel/cClosure.ml{,i}
lib/errors.ml{,i} -> lib/cErrors.ml{,i}
toplevel/cerror.ml{,i} -> toplevel/explainErr.mli{,i}

All IDE-specific files, including the XML protocol have been moved to ide/

Reduction functions

In closure.ml, we introduced the more precise reduction flags fMATCH, fFIX, fCOFIX.

We renamed the following functions:

Closure.betadeltaiota -> Closure.all
Closure.betadeltaiotanolet -> Closure.allnolet
Reductionops.beta -> Closure.beta
Reductionops.zeta -> Closure.zeta
Reductionops.betaiota -> Closure.betaiota
Reductionops.betaiotazeta -> Closure.betaiotazeta
Reductionops.delta -> Closure.delta
Reductionops.betalet -> Closure.betazeta
Reductionops.betadelta -> Closure.betadeltazeta
Reductionops.betadeltaiota -> Closure.all
Reductionops.betadeltaiotanolet -> Closure.allnolet
Closure.no_red -> Closure.nored
Reductionops.nored -> Closure.nored
Reductionops.nf_betadeltaiota -> Reductionops.nf_all
Reductionops.whd_betadelta -> Reductionops.whd_betadeltazeta
Reductionops.whd_betadeltaiota -> Reductionops.whd_all
Reductionops.whd_betadeltaiota_nolet -> Reductionops.whd_allnolet
Reductionops.whd_betadelta_stack -> Reductionops.whd_betadeltazeta_stack
Reductionops.whd_betadeltaiota_stack -> Reductionops.whd_all_stack
Reductionops.whd_betadeltaiota_nolet_stack -> Reductionops.whd_allnolet_stack
Reductionops.whd_betadelta_state -> Reductionops.whd_betadeltazeta_state
Reductionops.whd_betadeltaiota_state -> Reductionops.whd_all_state
Reductionops.whd_betadeltaiota_nolet_state -> Reductionops.whd_allnolet_state
Reductionops.whd_eta -> Reductionops.shrink_eta
Tacmach.pf_whd_betadeltaiota -> Tacmach.pf_whd_all
Tacmach.New.pf_whd_betadeltaiota -> Tacmach.New.pf_whd_all

And removed the following ones:

Reductionops.whd_betaetalet
Reductionops.whd_betaetalet_stack
Reductionops.whd_betaetalet_state
Reductionops.whd_betadeltaeta_stack
Reductionops.whd_betadeltaeta_state
Reductionops.whd_betadeltaeta
Reductionops.whd_betadeltaiotaeta_stack
Reductionops.whd_betadeltaiotaeta_state
Reductionops.whd_betadeltaiotaeta

In intf/genredexpr.mli, fIota was replaced by FMatch, FFix and FCofix. Similarly, rIota was replaced by rMatch, rFix and rCofix.

Notation_ops

Use Glob_ops.glob_constr_eq instead of Notation_ops.eq_glob_constr.

Logging and Pretty Printing

Printing functions have been removed from Pp.mli, which is now a purely pretty-printing interface. Functions affected are:

val pp          : std_ppcmds -> unit
val ppnl        : std_ppcmds -> unit
val pperr       : std_ppcmds -> unit
val pperrnl     : std_ppcmds -> unit
val pperr_flush : unit -> unit
val pp_flush    : unit -> unit
val flush_all   : unit -> unit
val msg         : std_ppcmds -> unit
val msgnl       : std_ppcmds -> unit
val msgerr      : std_ppcmds -> unit
val msgerrnl    : std_ppcmds -> unit
val message     : string -> unit

which are no more available. Users of Pp.pp msg should now use the proper Feedback.msg_* function. Clients also have no control over flushing, the back end takes care of it.

Also, the msg_* functions now take an optional ?loc parameter for relaying location to the client.

Feedback related functions and definitions have been moved to the Feedback module. message_level has been renamed to level. Functions moved from Pp to Feedback are:

val set_logger      : logger -> unit
val std_logger      : logger
val emacs_logger    : logger
val feedback_logger : logger

Changes in the Feedback format/Protocol.

The Message feedback type now carries an optional location, the main payload is encoded using the richpp document format.
The ErrorMsg feedback type is thus unified now with Message at level Error.

We now provide several loggers, log_via_feedback is removed in favor of set_logger feedback_logger. Output functions are:

val with_output_to_file : string -> ('a -> 'b) -> 'a -> 'b
val msg_error   : ?loc:Loc.t -> Pp.std_ppcmds -> unit
val msg_warning : ?loc:Loc.t -> Pp.std_ppcmds -> unit
val msg_notice  : ?loc:Loc.t -> Pp.std_ppcmds -> unit
val msg_info    : ?loc:Loc.t -> Pp.std_ppcmds -> unit
val msg_debug   : ?loc:Loc.t -> Pp.std_ppcmds -> unit

with the msg_* functions being just an alias for logger $Level.

The main feedback functions are:

val set_feeder : (feedback -> unit) -> unit
val feedback : ?id:edit_or_state_id -> ?route:route_id -> feedback_content -> unit
val set_id_for_feedback : ?route:route_id -> edit_or_state_id -> unit

Note that feedback doesn't take two parameters anymore. After refactoring the following function has been removed:

val get_id_for_feedback : unit -> edit_or_state_id * route_id

Kernel API changes

The interface of the Context module was changed. Related types and functions were put in separate submodules. The mapping from old identifiers to new identifiers is the following:

Context.named_declaration            --->  Context.Named.Declaration.t
Context.named_list_declaration       --->  Context.NamedList.Declaration.t
Context.rel_declaration              --->  Context.Rel.Declaration.t
Context.map_named_declaration        --->  Context.Named.Declaration.map_constr
Context.map_named_list_declaration   --->  Context.NamedList.Declaration.map
Context.map_rel_declaration          --->  Context.Rel.Declaration.map_constr
Context.fold_named_declaration       --->  Context.Named.Declaration.fold
Context.fold_rel_declaration         --->  Context.Rel.Declaration.fold
Context.exists_named_declaration     --->  Context.Named.Declaration.exists
Context.exists_rel_declaration       --->  Context.Rel.Declaration.exists
Context.for_all_named_declaration    --->  Context.Named.Declaration.for_all
Context.for_all_rel_declaration      --->  Context.Rel.Declaration.for_all
Context.eq_named_declaration         --->  Context.Named.Declaration.equal
Context.eq_rel_declaration           --->  Context.Rel.Declaration.equal
Context.named_context                --->  Context.Named.t
Context.named_list_context           --->  Context.NamedList.t
Context.rel_context                  --->  Context.Rel.t
Context.empty_named_context          --->  Context.Named.empty
Context.add_named_decl               --->  Context.Named.add
Context.vars_of_named_context        --->  Context.Named.to_vars
Context.lookup_named                 --->  Context.Named.lookup
Context.named_context_length         --->  Context.Named.length
Context.named_context_equal          --->  Context.Named.equal
Context.fold_named_context           --->  Context.Named.fold_outside
Context.fold_named_list_context      --->  Context.NamedList.fold
Context.fold_named_context_reverse   --->  Context.Named.fold_inside
Context.instance_from_named_context  --->  Context.Named.to_instance
Context.extended_rel_list            --->  Context.Rel.to_extended_list
Context.extended_rel_vect            --->  Context.Rel.to_extended_vect
Context.fold_rel_context             --->  Context.Rel.fold_outside
Context.fold_rel_context_reverse     --->  Context.Rel.fold_inside
Context.map_rel_context              --->  Context.Rel.map_constr
Context.map_named_context            --->  Context.Named.map_constr
Context.iter_rel_context             --->  Context.Rel.iter
Context.iter_named_context           --->  Context.Named.iter
Context.empty_rel_context            --->  Context.Rel.empty
Context.add_rel_decl                 --->  Context.Rel.add
Context.lookup_rel                   --->  Context.Rel.lookup
Context.rel_context_length           --->  Context.Rel.length
Context.rel_context_nhyps            --->  Context.Rel.nhyps
Context.rel_context_tags             --->  Context.Rel.to_tags

Originally, rel-context was represented as:

type Context.rel_context = Names.Name.t * Constr.t option * Constr.t

Now it is represented as:

type Context.Rel.Declaration.t = LocalAssum of Names.Name.t * Constr.t
                               | LocalDef of Names.Name.t * Constr.t * Constr.t

Originally, named-context was represented as:

type Context.named_context = Names.Id.t * Constr.t option * Constr.t

Now it is represented as:

type Context.Named.Declaration.t = LocalAssum of Names.Id.t * Constr.t
                                 | LocalDef of Names.Id.t * Constr.t * Constr.t

The various EXTEND macros do not handle specially the Coq-defined entries anymore. Instead, they just output a name that have to exist in the scope of the ML code. The parsing rules (VERNAC) ARGUMENT EXTEND will look for variables $name of type Gram.entry, while the parsing rules of (VERNAC COMMAND | TACTIC) EXTEND, as well as the various TYPED AS clauses will look for variables wit_$name of type Genarg.genarg_type. The small DSL for constructing compound entries still works over this scheme. Note that in the case of (VERNAC) ARGUMENT EXTEND, the name of the argument entry is bound in the parsing rules, so beware of recursive calls.

For example, to get wit_constr you must open Constrarg at the top of the file.
Evarutil was split in two parts. The new Evardefine file exposes functions define_evar_* mostly used internally in the unification engine.
The Refine module was moved out of Proofview.
```
Proofview.Refine.* --->  Refine.*
```

A statically monotonic evarmap type was introduced in Sigma. Not all the API has been converted, so that the user may want to use compatibility functions Sigma.to_evar_map and Sigma.Unsafe.of_evar_map or Sigma.Unsafe.of_pair when needed. Code can be straightforwardly adapted in the following way:

let (sigma, x1) = ... in
...
let (sigma, xn) = ... in
(sigma, ans)

should be turned into:

open Sigma.Notations

let Sigma (x1, sigma, p1) = ... in
...
let Sigma (xn, sigma, pn) = ... in
Sigma (ans, sigma, p1 +> ... +> pn)

Examples of Sigma.Unsafe.of_evar_map include:

Evarutil.new_evar env (Tacmach.project goal) ty   ----> Evarutil.new_evar env (Sigma.Unsafe.of_evar_map (Tacmach.project goal)) ty

The Proofview.Goal.*enter family of functions now takes a polymorphic continuation given as a record as an argument.

Proofview.Goal.enter begin fun gl -> ... end

should be turned into

open Proofview.Notations

Proofview.Goal.enter { enter = begin fun gl -> ... end }

Tacexpr.TacDynamic(Loc.dummy_loc, Pretyping.constr_in c) ---> Tacinterp.Value.of_constr c
Vernacexpr.HintsResolveEntry(priority, poly, hnf, path, atom) ---> Vernacexpr.HintsResolveEntry(Vernacexpr.({hint_priority = priority; hint_pattern = None}), poly, hnf, path, atom)
Pretyping.Termops.mem_named_context ---> Engine.Termops.mem_named_context_val
Global.named_context ---> Global.named_context_val
Context.Named.lookup ---> Environ.lookup_named_val

Search API

The main search functions now take a function iterating over the results. This allows for clients to use streaming or more economic printing.

XML Protocol

In several places, flat text wrapped in <string> tags now appears as structured text inside <richpp> tags.
The "errormsg" feedback has been replaced by a "message" feedback which contains <feedback\_content> tag, with a message_level attribute of "error".

Changes between Coq 8.4 and Coq 8.5

Refactoring : more mli interfaces and simpler grammar.cma

A new directory intf/ now contains mli-only interfaces :
- Constrexpr : definition of constr_expr, was in Topconstr
- Decl_kinds : now contains binding_kind = Explicit | Implicit
- Evar_kinds : type Evar_kinds.t was previously Evd.hole_kind
- Extend : was parsing/extend.mli
- Genredexpr : regroup Glob_term.red_expr_gen and Tacexpr.glob_red_flag
- Glob_term : definition of glob_constr
- Locus : definition of occurrences and stuff about clauses
- Misctypes : intro_pattern_expr, glob_sort, cast_type, or_var, ...
- Notation_term : contains notation_constr, was Topconstr.aconstr
- Pattern : contains constr_pattern
- Tacexpr : was tactics/tacexpr.ml
- Vernacexpr : was toplevel/vernacexpr.ml
Many files have been divided :
- vernacexpr: vernacexpr.mli + Locality
- decl_kinds: decl_kinds.mli + Kindops
- evd: evar_kinds.mli + evd
- tacexpr: tacexpr.mli + tacops
- glob_term: glob_term.mli + glob_ops + genredexpr.mli + redops
- topconstr: constrexpr.mli + constrexpr_ops + notation_expr.mli + notation_ops + topconstr
- pattern: pattern.mli + patternops
- libnames: libnames (qualid, reference) + globnames (global_reference)
- egrammar: egramml + egramcoq
New utility files : miscops (cf. misctypes.mli) and redops (cf genredexpr.mli).
Some other directory changes :
- grammar.cma and the source files specific to it are now in grammar/
- pretty-printing files are now in printing/
Inner-file changes :
- aconstr is now notation_constr, all constructors for this type now start with a N instead of a A (e.g. NApp instead of AApp), and functions about aconstr may have been renamed (e.g. match_aconstr is now match_notation_constr).
- occurrences (now in Locus.mli) is now an algebraic type, with
  - AllOccurrences instead of all_occurrences_expr = (false,[])
  - (AllOccurrencesBut l) instead of (all_occurrences_expr_but l) = (false,l)
  - NoOccurrences instead of no_occurrences_expr = (true,[])
  - (OnlyOccurrences l) instead of (no_occurrences_expr_but l) = (true,l)
- move_location (now in Misctypes) has two new constructors MoveFirst and MoveLast replacing (MoveToEnd false) and (MoveToEnd true)
API of pretyping.ml and constrintern.ml has been made more uniform
- Parametrization of understand_* functions is now made using "inference flags"
- Functions removed:
  - interp_constr_judgment (inline its former body if really needed)
  - interp_casted_constr, interp_type: use instead interp_constr with expected_type set to OfType or to IsType
  - interp_gen: use any of interp_constr, interp_casted_constr, interp_type
  - interp_open_constr_patvar
  - interp_context: use interp_context_evars (with a "evar_map ref") and call solve_remaining_evars afterwards with a failing flag (e.g. all_and_fail_flags)
  - understand_type, understand_gen: use understand with appropriate parameters
- Change of semantics:
  - Functions interp_*_evars_impls have a different interface and do not any longer check resolution of evars by default; use check_evars_are_solved explicitly to check that evars are solved. See also the corresponding commit log.
Tactics API: new_induct -> induction; new_destruct -> destruct; letin_pat_tac do not accept a type anymore
New file find_subterm.ml for gathering former functions subst_closed_term_occ_modulo, subst_closed_term_occ_decl (which now take and outputs also an evar_map), and subst_closed_term_occ_modulo, subst_closed_term_occ_decl_modulo (now renamed into replace_term_occ_modulo and replace_term_occ_decl_modulo).
API of Inductiveops made more uniform (see commit log or file itself).
API of intros_pattern style tactic changed; "s" is dropped in "intros_pattern" and "intros_patterns" is not anymore behaving like tactic "intros" on the empty list.
API of cut tactics changed: for instance, cut_intro should be replaced by "assert_after Anonymous"
All functions taking an env and a sigma (or an evdref) now takes the env first.

Changes between Coq 8.3 and Coq 8.4

Functions in unification.ml have now the evar_map coming just after the env
Removal of Tacinterp.constr_of_id

Use instead either global_reference or construct_reference in constrintern.ml.

Optimizing calls to Evd functions

Evars are split into defined evars and undefined evars; for efficiency, when an evar is known to be undefined, it is preferable to use specific functions about undefined evars since these ones are generally fewer than the defined ones.

Type changes in TACTIC EXTEND rules

Arguments bound with tactic(_) in TACTIC EXTEND rules are now of type glob_tactic_expr, instead of glob_tactic_expr * tactic. Only the first component is kept, the second one can be obtained via Tacinterp.eval_tactic.

ARGUMENT EXTEND

It is now forbidden to use TYPED simultaneously with {RAW,GLOB}_TYPED in ARGUMENT EXTEND statements.

Renaming of rawconstr to glob_constr

The "rawconstr" type has been renamed to "glob_constr" for consistency. The "raw" in everything related to former rawconstr has been changed to "glob". For more details about the rationale and scripts to migrate code using Coq's internals, see commits 13743, 13744, 13755, 13756, 13757, 13758, 13761 (by glondu, end of December 2010) in Subversion repository. Contribs have been fixed too, and commit messages there might also be helpful for migrating.

Changes between Coq 8.2 and Coq 8.3

Light cleaning in evaruil.ml

whd_castappevar is now whd_head_evar obsolete whd_ise disappears

Restructuration of the syntax of binders

binders_let -> binders
binders_let_fixannot -> binders_fixannot
binder_let -> closed_binder (and now covers only bracketed binders)
binder was already obsolete and has been removed

Semantical change of h_induction_destruct

Warning, the order of the isrec and evar_flag was inconsistent and has been permuted. Tactic induction_destruct in tactics.ml is unchanged.

Internal tactics renamed

There is no more difference between bindings and ebindings. The following tactics are therefore renamed

apply_with_ebindings_gen -> apply_with_bindings_gen
left_with_ebindings -> left_with_bindings
right_with_ebindings -> right_with_bindings
split_with_ebindings -> split_with_bindings

and the following tactics are removed

apply_with_ebindings (use instead apply_with_bindings)
eapply_with_ebindings (use instead eapply_with_bindings)

Obsolete functions in typing.ml

For mtype_of, msort_of, mcheck, now use type_of, sort_of, check

Renaming functions renamed

concrete_name -> compute_displayed_name_in
concrete_let_name -> compute_displayed_let_name_in
rename_rename_bound_var -> rename_bound_vars_as_displayed
lookup_name_as_renamed -> lookup_name_as_displayed
next_global_ident_away true -> next_ident_away_in_goal
next_global_ident_away false -> next_global_ident_away

Cleaning in commmand.ml

Functions about starting/ending a lemma are in lemmas.ml Functions about inductive schemes are in indschemes.ml

Functions renamed:

declare_one_assumption -> declare_assumption
declare_assumption -> declare_assumptions
Command.syntax_definition -> Metasyntax.add_syntactic_definition
declare_interning_data merged with add_notation_interpretation
compute_interning_datas -> compute_full_internalization_env
implicits_env -> internalization_env
full_implicits_env -> full_internalization_env
build_mutual -> do_mutual_inductive
build_recursive -> do_fixpoint
build_corecursive -> do_cofixpoint
build_induction_scheme -> build_mutual_induction_scheme
build_indrec -> build_induction_scheme
instantiate_type_indrec_scheme -> weaken_sort_scheme
instantiate_indrec_scheme -> modify_sort_scheme
make_case_dep, make_case_nodep -> build_case_analysis_scheme
make_case_gen -> build_case_analysis_scheme_default

Types:

decl_notation -> decl_notation option

Cleaning in libnames/nametab interfaces

Functions:

dirpath_prefix -> pop_dirpath
extract_dirpath_prefix pop_dirpath_n
extend_dirpath -> add_dirpath_suffix
qualid_of_sp -> qualid_of_path
pr_sp -> pr_path
make_short_qualid -> qualid_of_ident
sp_of_syntactic_definition -> path_of_syntactic_definition 
sp_of_global -> path_of_global
id_of_global -> basename_of_global
absolute_reference -> global_of_path
locate_syntactic_definition -> locate_syndef
path_of_syntactic_definition -> path_of_syndef
push_syntactic_definition -> push_syndef

Types:

section_path -> full_path

Cleaning in parsing extensions (commit 12108)

Many moves and renamings, one new file (Extrawit, that contains wit_tactic).

Cleaning in tactical.mli

tclLAST_HYP -> onLastHyp
tclLAST_DECL -> onLastDecl
tclLAST_NHYPS -> onNLastHypsId
tclNTH_DECL -> onNthDecl
tclNTH_HYP -> onNthHyp
onLastHyp -> onLastHypId
onNLastHyps -> onNLastDecls
onClauses -> onClause
allClauses -> allHypsAndConcl

and removal of various unused combinators on type "clause"

Changes between Coq 8.1 and Coq 8.2

Datatypes

List of occurrences moved from "int list" to "Termops.occurrences" (an alias to "bool * int list") ETIdent renamed to ETName

Functions

Eauto: e_resolve_constr, vernac_e_resolve_constr -> simplest_eapply
Tactics: apply_with_bindings -> apply_with_bindings_wo_evars
Eauto.simplest_apply -> Hiddentac.h_simplest_apply
Evarutil.define_evar_as_arrow -> define_evar_as_product
Old version of Tactics.assert_tac disappears
Tactics.true_cut renamed into Tactics.assert_tac
Constrintern.interp_constrpattern -> intern_constr_pattern
Hipattern.match_with_conjunction is a bit more restrictive
Hipattern.match_with_disjunction is a bit more restrictive

Universe names (univ.mli)

base_univ -> type0_univ  (* alias of Set is the Type hierarchy *)
prop_univ -> type1_univ  (* the type of Set in the Type hierarchy *)
neutral_univ -> lower_univ (* semantic alias of Prop in the Type hierarchy *)
is_base_univ -> is_type1_univ
is_empty_univ -> is_lower_univ

Sort names (term.mli)

mk_Set -> set_sort
mk_Prop -> prop_sort
type_0 -> type1_sort

Changes between Coq 8.0 and Coq 8.1

Functions

Util: option_app -> option_map
Term: substl_decl -> subst_named_decl
Lib: library_part -> remove_section_part
Printer: prterm -> pr_lconstr
Printer: prterm_env -> pr_lconstr_env
Ppconstr: pr_sort -> pr_rawsort
Evd: in_dom, etc got standard ocaml names (i.e. mem, etc)
Pretyping:
- understand_gen_tcc and understand_gen_ltac merged into understand_ltac
- type_constraints can now say typed by a sort (use OfType to get the previous behavior)
Library: import_library -> import_module

Constructors

Declarations: mind_consnrealargs -> mind_consnrealdecls
NoRedun -> NoDup
Cast and RCast have an extra argument: you can recover the previous behavior by setting the extra argument to "CastConv DEFAULTcast" and "DEFAULTcast" respectively
Names: "kernel_name" is now "constant" when argument of Term.Const
Tacexpr: TacTrueCut and TacForward(false,,) merged into new TacAssert
Tacexpr: TacForward(true,,) branched to TacLetTac

Modules

module Decl_kinds: new interface
module Bigint: new interface
module Tacred spawned module Redexpr
module Symbols -> Notation
module Coqast, Ast, Esyntax, Termast, and all other modules related to old syntax are removed
module Instantiate: integrated to Evd
module Pretyping now a functor: use Pretyping.Default instead

Internal names

OBJDEF and OBJDEF1 -> CANONICAL-STRUCTURE

Tactic extensions

printers have an extra parameter which is a constr printer at high precedence
the tactic printers have an extra arg which is the expected precedence
level is now a precedence in declare_extra_tactic_pprule
"interp" functions now of types the actual arg type, not its encapsulation as a generic_argument

Changes between Coq 7.4 and Coq 8.0

See files in dev/syntax-v8

Main changes between Coq 7.4 and Coq 8.0

Changes due to introduction of modules

Kernel

The module level has no effect on constr except for the structure of section_path. The type of unique names for constructions (what section_path served) is now called a kernel name and is defined by

type uniq_ident = int * string * dir_path (* int may be enough *)
type module_path =
  | MPfile of dir_path    (* reference to physical module, e.g. file *)
  | MPbound of uniq_ident (* reference to a module parameter in a functor *)
  | MPself of uniq_ident  (* reference to one of the containing module *)
  | MPdot of module_path * label
type label = identifier
type kernel_name = module_path * dir_path * label
                   ^^^^^^^^^^^   ^^^^^^^^   ^^^^^
                        |           |         \
                        |           |          the base name
                        |           \
                       /             the (true) section path
   example:                          (non empty only inside open sections)
   L = (* i.e. some file of logical name L *)
   struct
     module A = struct Def a = ... end
   end
   M = (* i.e. some file of logical name M *)
   struct
     Def t = ...
     N = functor (X : sig module T = struct Def b = ... end end) -> struct
       module O = struct
         Def u = ...
       end
       Def x := ... <M>.t ... <N>.O.u ... X.T.b ... L.A.a

and are self-references, X is a bound reference and L is a reference to a physical module.

Notice that functor application is not part of a path: it must be named by a "module M = F(A)" declaration to be used in a kernel name.

Notice that Jacek chose a practical approach, making directories not modules. Another approach could have been to replace the constructor MPfile by a constant constructor MProot representing the root of the world.

Other relevant informations are in kernel/entries.ml (type module_expr) and kernel/declarations.ml (type module_body and module_type_body).

Library

tables [Summaries] - the only change is the special treatment of the global environmet.
objects [Libobject] declares persistent objects, given with methods:
- cache_function specifying how to add the object in the current scope;
- load_function, specifying what to do when the module containing the object is loaded;
- open_function, specifying what to do when the module containing the object is opened (imported);
- classify_function, specyfying what to do with the object, when the current module (containing the object) is ended.
- subst_function
- export_function, to signal end_section survival

(Almost) Each of these methods is called with a parameter of type object_name = section_path * kernel_name where section_path is the full user name of the object (such as Coq.Init.Datatypes.Fst) and kernel_name is its substitutive internal version such as (MPself<Datatypes#1>,[],"Fst") (see above)

What happens at the end of an interactive module ?

(or when a file is stored and reloaded from disk)

All summaries (except Global environment) are reverted to the state from before the beginning of the module, and:

the objects (again, since last Declaremods.start_module or Library.start_library) are classified using the classify_function. To simplify consider only those who returned Substitute _ or Keep _.
If the module is not a functor, the subst_function for each object of the first group is called with the substitution [MPself "<Datatypes#1>" |-> MPfile "Coq.Init.Datatypes"]. Then the load_function is called for substituted objects and the "keep" object. (If the module is a library the substitution is done at reloading).
The objects which returned substitute are stored in the modtab together with the self ident of the module, and functor argument names if the module was a functor.

They will be used (substituted and loaded) when a command like Module M := F(N) or Module Z := N is evaluated

The difference between "substitute" and "keep" objects

The "keep" objects can only reference other objects by section_paths and qualids. They do not need the substitution function.

They will work after end_module (or reloading a compiled library), because these operations do not change section_path's

They will obviously not work after Module Z:=N.

These would typically be grammar rules, pretty printing rules etc.

The "substitute" objects can only reference objects by kernel_names. They must have a valid subst_function.

They will work after end_module and after Module Z:=N or Module Z:=F(M).

Other kinds of objects:

"Dispose" - objects which do not survive end_module As a consequence, objects which reference other objects sometimes by kernel_names and sometimes by section_path must be of this kind...
"Anticipate" - objects which must be treated individually by end_module (typically "REQUIRE" objects)

Writing subst_thing functions

The subst_thing shoud not copy the thing if it hasn't actually changed. There are some cool emacs macros in dev/objects.el to help writing subst functions this way quickly and without errors. Also there are *_smartmap functions in Util.

The subst_thing functions are already written for many types, including constr (Term.subst_mps), global_reference (Libnames.subst_global), rawconstr (Rawterm.subst_raw) etc

They are all (apart from constr, for now) written in the non-copying way.

Nametab

Nametab has been made more uniform. For every kind of thing there is only one "push" function and one "locate" function.

Lib

library_segment is now a list of object_name * library_item, where object_name = section_path * kernel_name (see above)

New items have been added for open modules and module types

Declaremods

Functions to declare interactive and noninteractive modules and module types.

Library

Uses Declaremods to actually communicate with Global and to register objects.

Other changes

Internal representation of tactics bindings has changed (see type Rawterm.substitution).

New parsing model for tactics and vernacular commands

Introduction of a dedicated type for tactic expressions (Tacexpr.raw_tactic_expr)
Introduction of a dedicated type for vernac expressions (Vernacexpr.vernac_expr)
Declaration of new vernacular parsing rules by a new camlp4 macro GRAMMAR COMMAND EXTEND ... END to be used in ML files
Declaration of new tactics parsing/printing rules by a new camlp4 macro TACTIC EXTEND ... END to be used in ML files

New organisation of THENS:

tclTHENS tac tacs : tacs is now an array
tclTHENSFIRSTn tac1 tacs tac2 : apply tac1 then, apply the array tacs on the first n subgoals and tac2 on the remaining subgoals (previously tclTHENST)
tclTHENSLASTn tac1 tac2 tacs : apply tac1 then, apply tac2 on the first subgoals and apply the array tacs on the last n subgoals
tclTHENFIRSTn tac1 tacs = tclTHENSFIRSTn tac1 tacs tclIDTAC (prev. tclTHENSI)
tclTHENLASTn tac1 tacs = tclTHENSLASTn tac1 tclIDTAC tacs
tclTHENFIRST tac1 tac2 = tclTHENFIRSTn tac1 [|tac2|]
tclTHENLAST tac1 tac2 = tclTHENLASTn tac1 [|tac2|] (previously tclTHENL)
tclTHENS tac1 tacs = tclTHENSFIRSTn tac1 tacs (fun _ -> error "wrong number")
tclTHENSV same as tclTHENS but with an array
tclTHENSi : no longer available

Proof_type: subproof field in type proof_tree glued with the ref field

Tacmach: no more echo from functions of module Refiner

Files plugins//g_.ml4 take the place of files plugins//.v.

Files parsing/{vernac,tac}extend.ml{4,i} implements TACTIC EXTEND andd VERNAC COMMAND EXTEND macros

File syntax/PPTactic.v moved to parsing/pptactic.ml

Tactics about False and not now in tactics/contradiction.ml

Tactics depending on Init now tactics/.ml4 (no longer in tactics/.v)

File tacinterp.ml moved from proofs to directory tactics

Changes between Coq 7.1 and Coq 7.2

The core of Coq (kernel) has meen minimized with the following effects:

kernel/term.ml split into kernel/term.ml, pretyping/termops.ml
kernel/reduction.ml split into kernel/reduction.ml, pretyping/reductionops.ml
kernel/names.ml split into kernel/names.ml, library/nameops.ml
kernel/inductive.ml split into kernel/inductive.ml, pretyping/inductiveops.ml

the prefixes "Is" ans "IsMut" have been dropped from kind_of_term constructors, e.g. IsRel is now Rel, IsMutCase is now Case, etc.

Files

changes.md

Latest commit

History

changes.md

File metadata and controls

Changes between Coq 8.8 and Coq 8.9

ML API

Unit testing

Changes between Coq 8.7 and Coq 8.8

Bug tracker

ML API

STM API

XML IDE Protocol

Changes between Coq 8.6 and Coq 8.7

Ocaml

ML API

Tactic API

Ltac API

Additional changes in tactic extensions

Error handling

Pretty printing

Pretty Printing and XML protocol

Stm API

Toplevel and Vernacular API

XML Protocol

Changes between Coq 8.5 and Coq 8.6

Parsing

Files

Reduction functions

Notation_ops

Logging and Pretty Printing

Kernel API changes

Search API

XML Protocol

Changes between Coq 8.4 and Coq 8.5

Refactoring : more mli interfaces and simpler grammar.cma

Changes between Coq 8.3 and Coq 8.4

Changes between Coq 8.2 and Coq 8.3

Light cleaning in evaruil.ml

Restructuration of the syntax of binders

Semantical change of h_induction_destruct

Internal tactics renamed

Obsolete functions in typing.ml

Renaming functions renamed

Cleaning in commmand.ml

Cleaning in libnames/nametab interfaces

Cleaning in parsing extensions (commit 12108)

Cleaning in tactical.mli

Changes between Coq 8.1 and Coq 8.2

Datatypes

Functions

Universe names (univ.mli)

Sort names (term.mli)

Changes between Coq 8.0 and Coq 8.1

Functions

Constructors

Modules

Internal names

Tactic extensions

Changes between Coq 7.4 and Coq 8.0

Main changes between Coq 7.4 and Coq 8.0

Changes due to introduction of modules

Kernel

Library

What happens at the end of an interactive module ?

The difference between "substitute" and "keep" objects

Writing subst_thing functions

Nametab

Lib

Declaremods

Library

Other changes

Changes between Coq 7.1 and Coq 7.2