* Fix#9759: Typing without -principal is broken in 4.11 and trunk
* compile stdlib in -principal mode
* never modify generic part of ty_expected_explained
* use generic_instance where possible
* add comment for -no-principal in stdlib__oo.cmi
Instead of the erasure scheme that was used up to now, where we
considered that the type was always principal.
Note: the erasure still happens when polymorphic variants appear in the
patterns, and the type of the scrutinee contains a Reither.
We produce exhaustivity counter-example in the order of the
specialized submatrices. Having submatrices in source order gives the
nice behavior that the clause that would naturally been inserted first
in the source is given first as a counter-example.
Consider for example:
function
| true, true -> true
| false, false -> false
The two counter-examples are (true, false) and (false, true).
Before this patch, (false, true) would be shown first.
After this patch, (true, false) is shown first.
This corresponds to the following natural completion order:
function
| true, true -> true
| true, false -> ?
| false, false -> false
| false, true -> ?
On the other hand, the ordering of the default submatrix, with respect
to the specialized submatrices, is not preserved -- it is always
ordered last.
One could intuitively expect the default submatrix to appear in the
position of the first omega row in the source. We tried this, and
it is not a good idea:
- the change is much more invasive as the interface of
`build_specialized_submatrices` has to change
- the behavior of the result is in fact unpleasant; it is not
intuitive to order counter-examples in this way.
For example, consider:
function
| _, None -> false
| true, Some true -> false
The two exhaustivity counter-examples are (true, Some false)
and (false, Some _). The second comes from the default submatrix:
morally it is (_, Some _), with "some other constructor missing from
the column" instead of the first _. There is no reason to suppose that
the user would want to place this (_, Some _) or (false, Some _)
counter-example first in the completed code; indeed, this intuition
would suggest writing an exhaustive covering of patterns of the
form (_, foo), inserted after the first clause, but then the other
clauses below become unnecessary!
When an omega patterns appears high in the column like this, it is
usually because there is a very specific matching condition to the
rest of its row, that justifies some shortcutting behavior. The
program is typically *not* completed by adding more specific matching
conditions.
Added special types for variants, records, constructors or labels type mismatch.
Printing additional info about types mismatch during compilation error.
improved error messages for fixed row polymorphic variants: keep track of the motivation behind a fixed row (e.g it was bound to an universal or existential type variable, or private) in the types themselves and use this explanation in error messages.
When a location is related to multiple lines of code, it is printed
incorrectly. More specifically, the end character is actually an
offset between the beginning and the end of the location.
This commit changes the format of the locations when they cover
multiple lines. It adds the end line and the end character is now a
proper column rather than an offset. It doesn't affect locations
related to a single line.
The old format was:
```
Line STARTLINE, characters STARTCHAR-OFFSET
```
The new format is:
```
Lines STARTLINE-ENDLINE, characters STARTCHAR-ENDCHAR
```
Note: Typos found with https://github.com/codespell-project/codespell
Here is the (semi-manual) command used to get (and correct) the typos:
$ codespell -i 3 -w --skip=".png,.gif,./ocaml/boot,./ocaml/.git,./ocaml/manual/styles,./ocaml/manual/manual/htmlman" -L minimise,instal,contructor,"o'caml",cristal,pres,clos,cmo,uint,iff,te,objext,nto,nd,mut,upto,larg,exten,leage,mthod,delte,tim,atleast,langage,hten,iwth,mke,contant,succint,methids,eles,valu,clas,modul,que,classe,missings,froms,defaut,correspondance,differents,configury,reachs,cas,approche,normale,dur,millon,amin,oje,transfert
Type variables whose name has a single quote as the second character
(such as ' a' or ' a'b) need to be printed with a whitespace after the
initial quote symbol, in order not to be confused with a character
literal.
Thomas Refis
Jacques Garrigue
Gabriel Scherer
Nicolás Ojeda Bär
Jeremy Yallop
Leo White
Leo White
Florian Angeletti
Mekhrubon Turaev
Mekhrubon Turaev
JPR
Louis Roché
Matthew Ryan
Thomas Refis
alainfrisch
Armaël Guéneau
Florian Angeletti
David Allsopp