This removes unnecessary movn, movf, lds, and a few other instructions.
Any instructions that has not side effects and writes to a slot that
isn't used can be removed. A number of other optimizations can follow
from this:
- Implement the def-aliasing-var optimization better
- This function can be iterated as a fix point until no more
instructions are removed.
- If we implement slot renaming, then we no longer need to free slots
and can simplify the initial code generation a lot.
This turns splices that are ignored into compiler errors. Other
alternatives here should also be considered, for example making this
a compiler warning rather than an error. For example, the latest
spork as of a3ee63c137ee3234987dbbca71b566994ff8ae8c has an error of this
kind, but the resulting program does work correctly.
Also disallow splice propagation - code of the
form (+ 1 (do ;[2 3 4]) 5).
While the old behavior was reasonable, it is not spelled out anywhere
in the documentation and was incidental rather than intentional.
Parameters of the same name of the function should probably take
precedence on name collision, following the principle of least surprise.
While generally we are not in the business of making a very chatty
compiler, this is a simple improvement that involves compiling
metadata before the binding, as well as adding a suggestion for `defn`
in case the compiler encounters an unexpected tuple.
Nested expression in the quasiquote were being compiled with the "hint"
flag passed to the expression compilation, essentially telling the
compiler to put intermediates into the final slot, possibly overwriting
other intermediate values. This fix removes that flags on any recursive
calls to quasiquote.
The current destructure pattern ends when '& is encountered.
This commit adds an error if it is followed by more than
a symbol to bind the array to.
Although its not critical since the extra items can be ignored,
they're a sign of some kind of mistake so its best to complain.
In destructure janet_type(_) == JANET_SYMBOL was used to check if a
value was a symbol.
This commit replaces that with the janet_checktype function,
because that function is used for the same purpose in other places.
This commit adds three checks to ensure & rest patterns are valid:
1. When checking for '& ensure the value is a symbol before unwrapping
2. Make sure '& is followed by a value
3. Make sure the value following '& is a symbol
Add support for using [& rest] to match the remaining values
in an array or tuple when destructuring.
the rest pattern is implemented by pushing remaining values in the
rhs to the stack once & is found on the lhs.
Then tuple is called and the result is assigned
to the next symbol on the lhs.
This commit DOES NOT implement handling for malformed patterns.
This changes the implementation of the `next` function which
is now used to implement each. This let's us iterate over
more types, not just tables and structs.
Because we use an amalgated build, feature
test macros should be set in a single file that
is included before any other headers, and is placed
at the top of the amalgamated build.
True top level unquote currently requires basically double compilation
as it currently stands. Also, implementing such double compilation
looses all source mapping information. This is a compromise
implementation that makes it clear that this works differently than
a true top-level unquote.