This removes the runtime dependency on a borrow into the program
source code.
It's not yet ideal because there are a lot of tokens where we really
don't care about the lexeme, but this is what the book does and I
am not going to change that.
Change-Id: I888e18f98597766d6f725cbf9241e8eb2bd839e2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2394
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... with this, functions now work.
Note that this bubbled up another weird code structure nit: The
parser::Function type should probably not carry its name directly.
However this doesn't matter much and I don't care right now.
Change-Id: If8e3b23f07033260433b9acd45f37c0e61fd2ff8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2393
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This slightly jiggles around interpret_block to let callers pass in an
environment.
Change-Id: I03112a38be0e8696242d8eae8d41da8c2cc66b48
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2392
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
In order to store a function in the interpreter's representation of a
callable, the lifetimes used throughout rlox need to be threaded
through properly.
This is currently not optimal, for two reasons:
* following the design of the book's scanner, the source code slice
needs to still be available at runtime. Rust makes this explicit,
but it seems unnecessary.
* the interpreter's lifetime is now bounded to be smaller than the
source's, which means that the REPL no longer persists state between
evaluations
Both of these can be fixed eventually by diverging the scanner from
the book slightly, but right now that's not my priority.
Change-Id: Id0bf694541ff59795cfdea3c64a965384a49bfe2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2391
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This is much easier to read & write. It's been annoying me all the way
through.
Change-Id: Ia91756d3111a2ce3f74e1c14bccc210118d221dd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2387
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This makes it easier to write interpreter tests, as we don't need to
look at output and such.
Change-Id: I6f8ce0cb0c482b8c00707d09e6be750c8e534176
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2384
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... and adds an example builtin which returns the current epoch.
The types introduced by this, especially in the interpreter module,
are going to be used for user-defined functions, too.
Change-Id: I0364a67241e94642cde08489ac711a340e30ebe8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2381
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This makes it possible to distinguish between literal and other
values, such as functions.
Change-Id: I4d87b96c2988e25a61eecfeeb56188fabfd0dc40
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2367
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This is currently a bit hacky because of the environment
wrapping/unwrapping, will refactor this to just keep a single Rc
around instead.
Change-Id: Iad1cbbe35112d0329248d4655a09260fc60644c8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2304
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Adds scoped environments using a sophisticated structure known as an
SRPT, which stands for "shitty parent pointer tree".
Change-Id: I62f66aabe6eb32ea01c4cabcca5b03cfefcc28ee
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2301
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This lets the parser collect multiple errors instead of returning
after the first one, with some optimistic synchronisation after
encountering something that looks wonky.
Change-Id: Ie9d0ce8de9dcc7a3d1e7aa2abe15f74cab0ab96b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2236
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... with the exception of parenthesised expressions, because error
threading is not implemented yet.
Change-Id: I8d455d85e647548d5b71cbfd3d078f4970dab7fb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2232
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... mostly some AST boilerplate and a first top-level rule, plus
boilerplate similar to that set up in the Scanner.
Change-Id: I605d1de23c47a3b3702ab4f62cd3371bc3988c7d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2194
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... and show them to users, very crudely.
Change-Id: If4491b14db1124313f6ab7e5fbfdce9fea501d11
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2193
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
Note that Lox does not support escapes, and I don't care about that.
Change-Id: Ie848cbc1164c4b005b15e29aad8fe723aaa68d1b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2190
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... they're just noisy at the moment. This isn't complete because it
doesn't thread through scanner errors.
Change-Id: I0f75d2b20fa3f57be1af5d1d8aa8059856855825
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2162
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This makes it easier to work with the Unicode issue. The original
string representation can be discarded.
Change-Id: I740be4cb9654679ea7950f3899c5c709b1e7a739
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2160
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... still not that interesting, but at this point slightly divergent
from the book:
The book embraces mutability for interpreter state, initially for
tracking whether an error condition has occured.
I avoid this by instead defining an error type and collecting the
error values, to be handled later on.
Notes: So far nothing special, but this is just the beginning of the
book. I like the style it is written in and it has pointed to some
interesting resources, such as a 1965 paper titled "The Next 700
Languages".
Change-Id: I030b38438fec9eb55372bf547af225138908230a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2144
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
... as well as a Nix derivation, because why not.
Change-Id: Iaf2591ab72676fe0732c3f807b3aa0cff13fb4ef
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2143
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This is going to be the first of two interpreters from "Crafting
Interpreters".
Change-Id: I354ddd2357444648d0245f35d92176dd176525d8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2142
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
