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* Generalize AnyTemplate type to Any in DAML-LF See #3131 for the motivation for this. The tl;dr is that we need something like AnyTemplate for choice types as well. Since the protobuf was already more general in anticipation of such a change, this change only changes the internal AST on the Haskell and Scala side. Since AnyTemplate change has never made it out of 1.dev, I updated the changelog in the LF spec instead of adding a new entry. * Update daml-lf/spec/daml-lf-1.rst Co-Authored-By: Andreas Herrmann <42969706+aherrmann-da@users.noreply.github.com> * windows debugging * more windows debugging * clean expunge * don’t cat the config file * remove comment on type equality * windows … * gnah * foobar * foobar * does anything ever work? * reenable caching * Do not build daml-lf-ast separately |
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DAML-LF archive
This component contains the .proto definitions specifying the format
in which DAML-LF packages are stored -- the DAML-LF archive.
The entry point definition is Archive in da/daml_lf.proto. Archive
contains some metadata about the actual archive (currently the hashing
function and the hash), and then a binary blob containing the archive.
The binary blob must be an ArchivePayload -- we keep it in binary form
to facilitate hashing, signing, etc. The encoding and decoding of the
payload is handled by Haskell and Java libraries in daml-core-package,
so that consumers and producers do not really need to worry about it.
ArchivePayload is a sum type containing the various DAML-LF versions
supported by the DAML-LF archive. Currently we have two versions:
DAML-LF-0, which is the legacy DAML core;DAML-LF-1, which is the first version of DAML-LF as specified by https://github.com/digital-asset/daml/blob/master/daml-lf/spec/daml-lf-1.rst.
Building
It produces two libraries containing code to encode / decode such definition, a Haskell one and a Java one:
$ bazel build //daml-lf/archive:daml_lf_haskell_proto
$ bazel build //daml-lf/archive:daml_lf_java_proto
Editing the .proto definitions
When editing the proto definitions, you must make sure to not change them in a backwards-incompatible way. To make sure this doesn't happen:
- DO NOT delete message fields;
- DO NOT change the number of a message field or an enum value;
- DO NOT change the type of a message field;
Note that "fields" include oneof fields. Also note that the "don't
delete fields" rule is there not because they introduce a backwards
incompatible change, but rather because after a field has been deleted
another commiter might redefine it with a different type without
realizing.
What is OK is renaming message fields while keeping the number and semantics unchanged. For example, if you have
message Foo {
bytes blah = 1;
}
it's OK to change it to
message Foo {
// this field is deprecated -- use baz instead!
bytes blah_deprecated = 1;
string baz = 2;
}
Conversion from the .proto to AST
The .proto definitions contain the serialized format for DAML-LF
packages, however the code to convert from the .proto definitions to
the actual AST lives elsewhere.