CHANGELOG.md 8.69 KB
Newer Older
Ralf Jung's avatar
Ralf Jung committed
1
2
3
In this changelog, we document "large-ish" changes to Iris that affect even the
way the logic is used on paper.  We also mention some significant changes in the
Coq development, but not every API-breaking change is listed.  Changes marked
4
`[#]` still need to be ported to the Iris Documentation LaTeX file(s).
5

Ralf Jung's avatar
Ralf Jung committed
6
## Iris 3.1.0 (unfinished)
7

Ralf Jung's avatar
Ralf Jung committed
8
9
Changes in and extensions of the theory:

Ralf Jung's avatar
Ralf Jung committed
10
* Add new modality: ■ ("plainly").
11
* Camera morphisms have to be homomorphisms, not just monotone functions.
Ralf Jung's avatar
Ralf Jung committed
12
* Add a proof that `f` has a fixed point if `f^k` is contractive.
13
14
* Constructions for least and greatest fixed points over monotone predicates
  (defined in the logic of Iris using impredicative quantification).
Ralf Jung's avatar
Ralf Jung committed
15
* Add a proof of the inverse of `wp_bind`.
Ralf Jung's avatar
Ralf Jung committed
16
17
18

Changes in Coq:

Ralf Jung's avatar
Ralf Jung committed
19
* Rename some things and change notation:
20
  - The unit of a camera: `empty` -> `unit`, `∅` -> `ε`
21
  - Disjointness: `⊥` -> `##`
Ralf Jung's avatar
Ralf Jung committed
22
  - A proof mode type class `IntoOp` -> `IsOp`
23
24
25
26
27
28
  - OFEs with all elements being discrete: `Discrete` -> `OfeDiscrete`
  - OFE elements whose equality is discrete: `Timeless` -> `Discrete`
  - Timeless propositions: `TimelessP` -> `Timeless`
  - Camera elements such that `core x = x`: `Persistent` -> `CoreId`
  - Persistent propositions: `PersistentP` -> `Persistent`
  - The persistent modality: `always` -> `persistently`
Ralf Jung's avatar
Ralf Jung committed
29
  - Consistently SnakeCase identifiers:
30
31
32
33
34
35
36
37
38
39
    + `CMRAMixin` -> `CmraMixin`
    + `CMRAT` -> `CmraT`
    + `CMRATotal` -> `CmraTotal`
    + `CMRAMorphism` -> `CmraMorphism`
    + `CMRADiscrete` -> `CmraDiscrete`
    + `UCMRAMixin` -> `UcmraMixin`
    + `UCMRAT` -> `UcmraT`
    + `DRAMixin` -> `DraMixin`
    + `DRAT` -> `DraT`
    + `STS` -> `Sts`
Ralf Jung's avatar
Ralf Jung committed
40
41
  - Many lemmas also changed their name.  `always_*` became `persistently_*`,
    and furthermore: (the following list is not complete)
42
43
44
45
46
47
48
49
50
51
52
    + `impl_wand` -> `impl_wand_1` (it only involves one direction of the
      equivalent)
    + `always_impl_wand` -> `impl_wand`
    + `always_and_sep_l` -> `and_sep_l`
    + `always_and_sep_r` -> `and_sep_r`
    + `always_sep_dup` -> `sep_dup`
    + `wand_impl_always` -> `impl_wand_persistently` (additionally,
      the direction of this equivalence got swapped for consistency's sake)
    + `always_wand_impl` -> `persistently_impl_wand` (additionally, the
      direction of this equivalence got swapped for consistency's sake)
  The following `sed` snippet should get you most of the way:
Ralf Jung's avatar
Ralf Jung committed
53
```
Ralf Jung's avatar
Ralf Jung committed
54
sed 's/\bPersistentP\b/Persistent/g; s/\bTimelessP\b/Timeless/g; s/\bCMRADiscrete\b/CmraDiscrete/g; s/\bCMRAT\b/CmraT/g; s/\bCMRAMixin\b/CmraMixin/g; s/\bUCMRAT\b/UcmraT/g; s/\bUCMRAMixin\b/UcmraMixin/g; s/\bSTS\b/Sts/g' -i $(find -name "*.v")
Ralf Jung's avatar
Ralf Jung committed
55
```
Ralf Jung's avatar
Ralf Jung committed
56
57
* Fix a bunch of consistency issues in the proof mode, and make it overall more
  usable.  In particular:
58
59
60
61
62
63
64
65
66
67
  - All proof mode tactics start the proof mode if necessary; `iStartProof` is
    no longer needed and should only be used for building custom proof mode
    tactics.
  - Change in the grammar of specialization patterns: `>[...]` -> `[> ...]`
  - Various new specification patterns for `done` and framing.
  - There is common machinery for symbolic execution of pure reductions. This
    is provided by the type classes `PureExec` and `IntoVal`.
  - There is a new connective `tc_opaque`, which can be used to make definitions
    opaque for type classes, and thus opaque for most tactics of the proof
    mode.
Ralf Jung's avatar
Ralf Jung committed
68
69
70
71
72
73
74
75
  - Define Many missing type class instances for distributing connectives.
  - Implement the tactics `iIntros (?)` and `iIntros "!#"` (i.e. `iAlways`)
    using type classes. This makes them more generic, e.g., `iIntros (?)` also
    works when the universal quantifier is below a modality, and `iAlways` also
    works for the plainness modality.  A breaking change, however, is that these
    tactics now no longer work when the universal quantifier or modality is
    behind a type class opaque definition.  Furthermore, this can change the
    name of anonymous identifiers introduced with the "%" pattern.
Ralf Jung's avatar
Ralf Jung committed
76
77
78
79
* Make `ofe_fun` dependently typed, subsuming `iprod`.  The latter got removed.
* Generalize `saved_prop` to let the user choose the location of the type-level
  later.  Rename the general form to `saved_anything`.  Provide `saved_prop` and
  `saved_pred` as special cases.
Ralf Jung's avatar
Ralf Jung committed
80
81
82
* Define the generic `fill` operation of the `ectxi_language` construct in terms
  of a left fold instead of a right fold. This gives rise to more definitional
  equalities.
Robbert Krebbers's avatar
Robbert Krebbers committed
83
84
85
86
87
* The language hierarchy (`language`, `ectx_language`, `ectxi_language`) is now
  fully formalized using canonical structures instead of using a mixture of
  type classes and canonical structures. Also, it now uses explicit mixins. The
  file `program_logic/ectxi_language` contains some documentation on how to
  setup Iris for your language.
Ralf Jung's avatar
Ralf Jung committed
88
* Improved big operators:
89
  + They are no longer tied to cameras, but work on any monoid
Ralf Jung's avatar
Ralf Jung committed
90
91
  + The version of big operations over lists was redefined so that it enjoys
    more definitional equalities.
92
* Various improvements to `solve_ndisj`.
Robbert Krebbers's avatar
Robbert Krebbers committed
93
94
95
* Some extensions/improvements of heap_lang:
  - Improve handling of pure (non-state-dependent) reductions.
  - Add fetch-and-add (`FAA`) operation.
Robbert Krebbers's avatar
Robbert Krebbers committed
96
  - Syntax for all Coq's binary operations on `Z`.
97
98
99
* Use `Hint Mode` to prevent Coq from making arbitrary guesses in the presence
  of evars, which often led to divergence. There are a few places where type
  annotations are now needed.
Ralf Jung's avatar
Ralf Jung committed
100
* Move the `prelude` folder to its own project: std++
101
102
* The rules `internal_eq_rewrite` and `internal_eq_rewrite_contractive` are now
  stated in the logic, i.e. they are `iApply` friendly.
103

Ralf Jung's avatar
Ralf Jung committed
104
## Iris 3.0.0 (released 2017-01-11)
105

Ralf Jung's avatar
Ralf Jung committed
106
107
108
* There now is a deprecation process.  The modules `*.deprecated` contain
  deprecated notations and definitions that are provided for backwards
  compatibility and will be removed in a future version of Iris.
Ralf Jung's avatar
Ralf Jung committed
109
* View shifts are radically simplified to just internalize frame-preserving
110
  updates.  Weakestpre is defined inside the logic, and invariants and view
Ralf Jung's avatar
Ralf Jung committed
111
  shifts with masks are also coded up inside Iris.  Adequacy of weakestpre is
112
  proven in the logic. The old ownership of the entire physical state is
Ralf Jung's avatar
Ralf Jung committed
113
114
  replaced by a user-selected predicate over physical state that is maintained
  by weakestpre.
115
* Use OFEs instead of COFEs everywhere.  COFEs are only used for solving the
116
117
  recursive domain equation.  As a consequence, CMRAs no longer need a proof of
  completeness.  (The old `cofeT` is provided by `algebra.deprecated`.)
118
* Implement a new agreement construction.  Unlike the old one, this one
119
120
  preserves discreteness.  dec_agree is thus no longer needed and has been moved
  to algebra.deprecated.
121
122
123
* Renaming and moving things around: uPred and the rest of the base logic are in
  `base_logic`, while `program_logic` is for everything involving the general
  Iris notion of a language.
124
125
126
127
* Renaming in prelude.list: Rename `prefix_of` -> `prefix` and `suffix_of` ->
  `suffix` in lemma names, but keep notation ``l1 `prefix_of` l2`` and ``l1
  `suffix_of` l2``.  `` l1 `sublist` l2`` becomes ``l1 `sublist_of` l2``. Rename
  `contains` -> `submseteq` and change `` l1 `contains` l2`` to ``l1 ⊆+ l2``.
Ralf Jung's avatar
Ralf Jung committed
128
129
130
* Slightly weaker notion of atomicity: an expression is atomic if it reduces in
  one step to something that does not reduce further.
* Changed notation for embedding Coq assertions into Iris.  The new notation is
131
  ⌜φ⌝.  Also removed `=` and `⊥` from the Iris scope.  (The old notations are
Ralf Jung's avatar
Ralf Jung committed
132
  provided in `base_logic.deprecated`.)
133
* Up-closure of namespaces is now a notation (↑) instead of a coercion.
134
135
* With invariants and the physical state being handled in the logic, there is no
  longer any reason to demand the CMRA unit to be discrete.
Ralf Jung's avatar
Ralf Jung committed
136
* The language can now fork off multiple threads at once.
137
138
* Local Updates (for the authoritative monoid) are now a 4-way relation with
  syntax-directed lemmas proving them.
Ralf Jung's avatar
Ralf Jung committed
139
140
141

## Iris 2.0

Ralf Jung's avatar
Ralf Jung committed
142
143
144
145
* [heap_lang] No longer use dependent types for expressions.  Instead, values
  carry a proof of closedness.  Substitution, closedness and value-ness proofs
  are performed by computation after reflecting into a term langauge that knows
  about values and closed expressions.
146
147
* [program_logic/language] The language does not define its own "atomic"
  predicate.  Instead, atomicity is defined as reducing in one step to a value.
148
149
150
151
152
* [program_logic] Due to a lack of maintenance and usefulness, lifting lemmas
  for Hoare triples are removed.

## Iris 2.0-rc2

Ralf Jung's avatar
Ralf Jung committed
153
This version matches the final ICFP 2016 paper.
154
155

* [algebra] Make the core of an RA or CMRA a partial function.
Ralf Jung's avatar
Ralf Jung committed
156
* [program_logic/lifting] Lifting lemmas no longer round-trip through a
Ralf Jung's avatar
Ralf Jung committed
157
158
159
  user-chosen predicate to define the configurations we can reduce to; they
  directly relate to the operational semantics.  This is equivalent and
  much simpler to read.
Ralf Jung's avatar
Ralf Jung committed
160
161
162

## Iris 2.0-rc1

Ralf Jung's avatar
Ralf Jung committed
163
This is the Coq development and Iris Documentation as submitted to ICFP 2016.