* feat: add 'when' functions for Maybe and Result
These functions enable users to execute some side-effecting function
(one that returns unit and take no arguments) based on the contents of a
Maybe or Result.
`when-success`: Executes a side-effect when given a `Result.Success`
`when-error`: Executes a side-effect when given a `Result.Error`
`when-just`: Executes a side-effect when given a `Maybe.Just`
`when-nothing`: Executes a side-effect when given a `Maybe.Nothing`
* docs: add Control to core lib doc generation
* feat: Add support for emitting literal C
This commit adds a new Obj type, C, as well as a command for emitting C
literals (which are represented by this object).
This is necessary for circumstances in which Carp's handling of
templates and emission orders prevents interop with C. For example, the
c11 macro static_assert must only take a string literal in its second
position. However, Carp's memory management will typically assign a
string literal (in Carp) to an anonymous variable, which makes them
impossible to use with static_assert. The new emit-c command will
support this use case:
```
(static-assert 0 (Unsafe.emit-c "\"message!\""))
```
The literal string "message!" will be emitted in the compiler's C output
in the position corresponding to the macro call.
We also add a special type for c literals, CTy, to prevent conflating
them with Strings. This helps maintainers define clear boundaries and
express what interop code requires the use of literal C.
Likewise, we need to emit `c_code` to represent this type in C. This
wouldn't be necessary except that Carp sometimes auto-generates
functions that refer to Carp types in their C equivalents, so we need
this for completeness. It is typed as the void pointer.
N.B. That the command is not yet exposed in Carp in this commit.
Thanks to @TimDeve for recommending the name emit-c!
* feat: Add preproc command and add emit-c to Unsafe module
This commit adds the preproc command, which enables users to emit
arbitrary C in the compilers emitted C output.
The C emitted by calls to preproc will be appended to the output after
include directives but prior to any other emissions. One can use it to
call preprocessor directives in C, define helper functions etc.
preproc takes a C type value as an argument and must be used in
conjunction with emit-c. Both functions are added to the Unsafe module
to signal their dangerousness.
One can use `register` in combination with preproc to define code
entirely in Carp and obviate the need of additional header files. For
example:
```
(Unsafe.preproc (Unsafe.emit-c "#define FOO 0"))
(Unsafe.preproc (Unsafe.emit-c "void foo() { printf(\"%d\\n\", 1); }"))
(register FOO Int)
(register foo (Fn [] ()))
(defn main []
(do (foo)
(IO.println &(fmt "%d" FOO))))
```
The prior example emits C that defines a FOO macro and foo function,
which are both referenced in the main function emitted by Carps normal
processing. Here's what the output looks like:
```
// .. several other includes emitted by the compiler...
void foo() { printf("%d\n", 1); }
//Types:
// Depth 3
typedef struct {
union {
struct {
Long member0;
} Just;
// Nothing
char __dummy;
} u;
char _tag;
} Maybe__Long;
```
The C passed to preproc calls is emitted prior to Carps other emissions,
ensuring the user has access to these definitions before any Carp code
is called.
* docs: Add documentation on emit-c and preproc
* feat: add macros for emitting C compiler directives
This suite of macros uses the `Unsafe.emit-c` and `Unsafe.preproc`
functions to provide macros for emitting common C compiler directives,
such as #ifdef, #define, #pragma and others.
* refactor: Groups Dynamic together in Macros.carp
* fix: Fixes doc for `hidden` referring to the wrong symbol
* feat: Adds defn- & def- macros
Adding these macros as a shortand for declaring a def or defn and making
them `hidden` and `private`, useful to keep things internal to a module.
* test: Adds expected error output tests for def- & defn-
* refactor: Changes position of Module and Interface section in LanguageGuide
Trying to introduce concepts in the same order they are referred to in
the examples: structs > modules > interfaces.
* docs: Adds private & hidden section in the LanguageGuide
* refactor: move Context updates into functions
Previously, we had a lot of instances of updating Context records
directly, replacing environments where needed. This commit replaces
those hand-written record setting instances with functions, which should
allow us to more gracefully abstract over any preprocessing we should
have to do and help ensure we're updating contexts in the right way.
* refactor: replace inline context manipulation in primitives
Like the commit that altered Eval before it, this commit leverages
Context functions to remove a bunch of inline record field setting code
and direct env manipulation.
* refactor: replace generic binder lookups with contextual ones
* refactor: move true and false XObjs into Obj.hs
Previously, trueXObj and falseXObj were defined in Commands.hs, but
since they're just literal constructed XObj values, I feel Obj.hs is a
more appropriate home for them and makes them more widely accessible to
other modules without needing to import Commands.
* refactor: model symbol qualification requirements at typelevel
This commit refactors the Qualify module to express symbol qualification
at type level. In the past, all functions operated on SymPaths. In some
cases, the functions operated on paths that *were not yet qualified* and
so the functions would perform qualification inline. Contrarily, other
functions like define received XObjs (from another part of the codebase
entirely!) that were already fully qualified, and so it would be a grave
mistake to re-qualify them.
In the general case, it's difficult or impossible to tell across modules
whether or not a given SymPath is coming in qualified or unqualified,
which can easily lead to mistakes of double-qualification, e.g.
transforming `Foo.bar` into `Foo.Foo.bar`.
Modelling qualification in the type system enables us to avoid the
problem by distinguishing between unqualified and qualified paths. A
function receiving an SymPath can safely qualify it, whereas a function
receiving a QualifiedPath should not further qualify the path. This
helps better express and ensure constraints across modules.
In addition, this commit also refactors a few functions where there was
opportunity to do so.
* refactor: remove eval call from `doc`
This can lead to problems where a doc call intended to be evaluated
later (in a macro body) is evaluated *immediately* resulting in a
binding being added to the wrong scope (see the function reverse in
core).
The reason this behavior crops up now is that a special case for
evaluating module contexts was removed last commit--this special case
caused problems of its own, and the real root of things stems from the
unnecessary eval call. Generally, evaling a doc call provides no benefit
other than making evaluation of the meta set immediate in the repl,
which is easy enough for one to do on one's own by calling eval where
needed.
* refactor: use do notation to clarify case qualification
* refactor: rename runQualified to unQualified
@eriksvedang pointed out the `run` prefix typically denotes a monad. As
`Qualified` is not monadic (no monad instance defined) we drop the `r`
to ensure we don't mislead readers.
* refactor: convert a few more binds to do notation
Do notation is generally clearer in cases where we use mapM, etc. We can
also leverage liftM frequently in the qualification functions to
transform a Qualified xobj back into an xobj for further use.
* refactor: temporarily restore special case in meta set
Meta set disallows setting the meta of a prefixed, absolute path such as
`Foo.bar`. It only allows relative, unqualified paths `bar` and uses the
current context to determine the appropriate module.
If we eventually throw and error from envInsertAt, we can remove this
special case. I intend to do that later, but for now we'll keep the
special case to make for a more pleasant user experience.
* add sketch for drop
* add drop example
* correct drop ordering
* fix: simplify drop and add to deleter
* docs: add drop docs
* fix: use a sound lifetime var
* feat: a proper dynamic numeric tower
The following things were changed and/or added:
- `Dynamic.neg` was added
- `Dynamic.mod` was changed to work on float values
- `Dynamic.cxr` was changed to work with `0` instructions
- `Dynamic.=` was changed to ignore the type of the number
- `Dynamic.round` was added
- dynamic arithmetic was changed to respect the numeric type tower
- the instances of `Eq` and `Ord` for `Number` are no longer derived, so that they work across numeric types
- the instance of `Num` for `Number` was changed to work across numeric types
- `promoteNumber` was added as a type function to implement the numeric tower.
The numeric tower is as follows:
Byte -> Int -> Long -> Float -> Double
* test: add tests for cxr, neg, and =
* test: add tests for Dynamic.round
* fix: make set! work with dynamic args (thanks @hellerve)
Like `let` before it, we used to bind function arguments to their values
only, which wasn't accounted for in `set!` such that one could not
`set!` `i` in `defndynamic [i] ...`. To fix this for let bindings we
introduced a `LetDef` form for consistency with Def forms. This commit
renames `LetDef` to `LocalDef` and uses it as a value for function
arguments in addition to let bindings, ensuring `set!` works on function
arguments too. Big thanks to @hellerve for the suggestion!
* test: add regression test for set! on dynamic function args