lvalues
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id = "01HPD4XQQ5WM0APCAX014HM43V"
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+ <span class="badge blue">featured</span> tairu - an interactive exploration of 2D autotiling techniques
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+ <span class="badge blue">featured</span> tairu - an interactive exploration of 2D autotiling techniques
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% content.link = "programming/blog/lvalues"
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id = "01HY5R1ZW0M0Y5KQ1E8F0Q73ZT"
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+ places, or what is up with `*x` not always meaning the same thing
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% content.link = "programming/blog/or-types"
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% content.link = "programming/blog/or-types"
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id = "01HTWN4XB2YMF3615BE8V6Y76A"
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id = "01HTWN4XB2YMF3615BE8V6Y76A"
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+ OR-types
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+ OR-types
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337
content/programming/blog/lvalues.tree
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337
content/programming/blog/lvalues.tree
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%% title = "places, or what is up with *x not always meaning the same thing in different contexts"
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% id = "01HY5R1ZV9DD7BV0F66Y0DHAEA"
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- I recently got a question from my someone telling me they doesn't understand why `*x` does not read from the pointer `x` when on the left-hand side of an assignment.
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% id = "01HY5R1ZV9G92SVA0XP7CG1X6K"
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- as in this case:
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```c
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void example(int *x) {
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int y = *x; // (1)
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*x = 10; // (2)
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}
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```
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% id = "01HY5R1ZV9MVWYF9VNPK403JDE"
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- it seems pretty weird, right? why does it read from the pointer in declaration `(1)`, but not in the assignment `(2)`?
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% id = "01HY5R1ZV9N9AY0HAYEWC0RBFT"
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- doesn't `*x` mean "read the value pointed to by `x`?"
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% id = "01HY5R1ZV9WJM9DMW5QGK04DCR"
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- TL;DR: the deal with this example is that `*x` *does not mean* "read from the location pointed to by `x`", but _just_ "the location pointed to by `x`".
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% id = "01HY5R1ZV9JN9GZ8BECJ0KV1FC"
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- **`*x` is not a _value_, it's a _memory location_, or _place_ in Rust parlance**
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% id = "01HY5R1ZV9QVH3W5BRS16V6EPG"
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- same thing with `x`
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% id = "01HY5R1ZV9RQQCBNFHY0ZSX4RP"
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- same thing with `some_struct.abc` or `some_struct->abc`
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% id = "01HY5R1ZV9BMQ7NZJ06B0W48HP"
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- but instead of jumping to conclusions, let's go back to the beginning.
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let's think, what is it that makes places _different_?
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% id = "01HY5R1ZV9JGE9FTN9CN736FJN"
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- the main thing is that you can write to them and create references to them.
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for instance, this doesn't work:
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```c
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void example(void) {
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1 = 2; // error!
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}
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```
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but this does:
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```c
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void example(void) {
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int i;
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i = 2; // fine!
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}
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```
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% id = "01HY5R1ZV91NN3YMXFNRACPDS7"
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- so really, places are kind of a different _type_ - we can do certain additional operations with them, such as writing!
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% id = "01HY5R1ZV9KH99CGCFM7TM1ZZB"
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- we'll call this type `place(T)`, where `T` is any arbitrary type that is stored at the memory location represented by the `place(T)`.
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% id = "01HY5R1ZV9F6BEQ5RHRPZPRVM6"
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- `place(T)` behaves a bit weirdly compared to other types.
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for starters, it is impossible to write the type down in C code, so we're always bound to turn `place(T)` into something else quickly after its creation.
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% id = "01HY5R1ZV92VA27TGY6DJPZNP9"
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- for instance, in this example:
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```c.types
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void take_int(int x);
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void example(int x) {
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take_int(x /*: place(int) */);
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}
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```
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the type of `x` being passed into the `take_int` function is `place(int)`, but since that function accepts an `int`, we convert from `place(int)`
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to a regular `int`.
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% id = "01HY5R1ZV9ST0B5PHERGD4J4R8"
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- this conversion happens implicitly and involves _reading_ from the place -
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remember that places represent locations in memory, so they're a bit like pointers.
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we have to read from them before we can access the value.
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% id = "01HY5R1ZV9E1NSCCTF1CXPMY3D"
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- but there are operations in the language that _expect_ a `place(T)`, and therefore do not perform the implicit conversion.
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% id = "01HY5R1ZV95BHSV9MF4Z46M377"
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+ we're able to describe these operations as _functions_ which take in a type `T` and return a type `U` - written down like `T -> U`.
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% id = "01HY5R1ZV90Z3S1FZ65R977P8Y"
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- this notation is taken from functional languages like Haskell.
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% id = "01HY5R1ZV9RERR87NHVSGS6TWP"
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- the `->` operator is _right-associative_ - `T -> U -> V` is a function which returns a function `U -> V`, not a function that accepts a `T -> U`.
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% id = "01HY5R1ZV9CG67DEA8Y649D40T"
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- one of these operations is _assignment_, which is like a function `place(T) -> T -> T`.
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it accepts a `place(T)` to write to, a `T` to write to that place, and returns the `T` written.
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note that in that case no read occurs, since the implicit conversion described before does not apply.
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```c.types
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void example(void) {
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int x = 0;
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x /*: place(int) */ = 1 /*: int */; /*-> int (discarded) */
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}
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```
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% id = "01HY5R1ZV9MNZKK381TS7K3VR2"
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- another one of these operations is the _`&` reference operator_, which is like a function `place(T) -> T*`.
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it accepts a `place(T)` and returns a pointer `T*` that points to the place's memory location in exchange.
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```c.types
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void example(void) {
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int x = 0;
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int* p = &(x /*: place(T) */);
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}
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```
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% id = "01HY5R1ZV9YN7H33BMK0NPX4QT"
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- and of course its analogue, the _`*` dereferencing operator_, which does not consume a place, but produces one.
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it accepts a `T*` and produces a `place(T)` that is placed at the pointer's memory location - it's the reverse of `&x`, `T* -> place(T)`.
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```c
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void example(int* x) {
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int y = *x;
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}
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```
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% id = "01HY5R1ZV9KZZARNK8KXZTGAFX"
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- another couple of operations that accept a `place(T)` is the _`.` and `[]` operators_, both of which can be used to refer to subplaces
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within the place.
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% id = "01HY5R1ZV9N6PY2ANQC45NN27E"
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- the difference is that `.` is a _static, compile-time known_ subplace, while `[]` may be _dynamic, runtime known_.
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% id = "01HY5R1ZV99N78RA7Z5GSVVPRB"
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- the `.` operator takes in a `place(T)` and returns a `place(U)` depending on the type of structure field we're referencing.
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% id = "01HY5R1ZV99PZT6SDK2HRCRMAZ"
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- since there is no type that represents the set of fields of a structure `S`, we'll invent a type `anyfield(S)` which represents that set.
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% id = "01HY5R1ZV9RYF2P5X53VW9S9K8"
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- the type of a specific field `f` in the structure `S` is `field(S, f)`.
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% id = "01HY5R1ZV9PACB0HVE976TZZ69"
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- we'll also introduce a type `fieldtype(F)` which is the type stored in the field `F`.
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% id = "01HY5R1ZV99M92Z0XH1H3385JE"
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- given that, the type of the `.` operator is `place(T) -> F -> place(fieldtype(F))`, where `F` is an `anyfield(T)`.
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% id = "01HY5R1ZV9VZFHRKY4QWBDTFJ7"
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- example:
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```c.types
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void example(void) {
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struct S { int x; } s;
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s /*: place(struct S) */;
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s /*: place(struct S) */ .x /*: field(struct S, x) */; /*-> place(int) (discarded) */
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}
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```
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% id = "01HY5R1ZV952B3C5AHFME5TJG4"
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- the `[]` operator takes in a `T*`, a `ptrdiff_t` to offset the pointer by, and returns a `place(T)` whose memory location is the offset pointer.
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the function signature is therefore `T* -> ptrdiff_t -> place(T)`.
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example:
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```c.types
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void example(int* array) {
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int* p = &((array /*: int* */)[123] /*: place(int) */);
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}
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```
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% id = "01HY5R1ZV9VC2NNFKY9W0AE8F1"
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- we can actually think of this `a[i]` operator as syntax sugar for `*(a + i)`.
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% id = "01HY5R1ZV9SKX5QGJCBRG5QAD9"
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- this has a funny consequence where `array[0]` is equivalent to `0[array]` -
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offsetting a pointer is just addition, and addition is commutative.
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therefore we can swap the operands to `[]` and it will work just fine!
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% id = "01HY5R1ZV9MQWK5VQZQG8JJ03J"
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- I do wonder though why it doesn't produce a warning.
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I'm no standards lawyer, but I *believe* this may have something to do with implicit type conversions - the `0` gets promoted to a
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pointer as part of the desugared addition.
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I really need to read up about C's type promotion rules.
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% id = "01HY5R1ZV9KA2Q3TKQWQPS19KV"
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- now I have to confess, I lied to you.
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there are no places in C.
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% id = "01HY5R1ZV9PAD1XRS29YV64GV2"
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- the C standard actually calls this concept "lvalues", which comes from the fact that they are **values** which are valid
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**l**eft-hand sides of assignment.
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% id = "01HY5R1ZV9BNZM45RK2AW8BF5N"
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+ however, I don't like that name since it's quite esoteric - if you tell a beginner "`x` is not an lvalue," they will look at you confused.
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but if you tell a beginner "`x` is not a place in memory," then it's immediately more clear!
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so I will keep using the Rust name despite the name "lvalues" technically being more "correct" and standards-compliant.
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% id = "01HY5R1ZV9DXQ8AQJXVK1JE9XS"
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- I'm putting "correct" in quotes because I don't believe this is a matter of correctness, just opinion.
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% id = "01HY5R1ZV9HP593J62VWDBWHK4"
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- what's interesting about `place(T)` is that it's actually a real type in C++ - except under a different name: `T&`.
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% id = "01HY5R1ZV961P77W5TPDP9AMT9"
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- references are basically a way of introducing places into the type system for real, which is nice,
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but on the other hand having places bindable to names results in some weird holes in the language.
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% id = "01HY5R1ZV9F292M89VEBSMB80F"
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- to begin with, in C we could assume that referencing any variable `T x` by its name `x` would produce a `place(T)`.
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this is a simple and clear rule to understand.
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% id = "01HY5R1ZV9WPRVN3S84B7H9W25"
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- in C++, this is no longer the case - referencing a variable `T x` by its name `x` produces a `T&`,
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but referencing a variable `T& x` by its name `x` produces a `T&`, not a `T& &`!
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in layman's terms, C++ makes it impossible to rebind references to something else.
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you can't make this variable point to `y`:
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<!-- NOTE: using `c` syntax here instead of `cpp` because I don't have a working C++ syntax at the moment! -->
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```c
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int x = 0;
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int y = 1;
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int& r = x;
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r = y; // nope, this is just the same as x = y
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```
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% id = "01HY5R1ZV9FQX72E6XDJ8BHY7K"
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- and it's not like it could've been done any better - if we got a `T& &` instead, we'd be able to reassign a different place to
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the variable, but then we'd get a type mismatch on something like `r = 1`
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% id = "01HY5R1ZV98W2X9HSG1KM7CDPN"
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- because assignment is `T& -> T -> T`;
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if our `T` is `int& &`, the expected signature is `int& & -> int& -> int&`, but we're providing an `int`, not an `int&` -
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and we can't make a reference out of a value!
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% id = "01HY5R1ZV9AVSDRGP8XYG56KNK"
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- so we'd need a way of doing `T& -> T`, but guess what: (almost) this already exists and is called "pointers" and "the unary `*` operator".
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% id = "01HY5R1ZV99T9X3ANYQJS40NBX"
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- except of course, with pointers the signature is `T* -> T&`.
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% id = "01HY5R1ZV94MHBS9RERA4CWPTM"
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- so by introducing references, C++ was actually made less consistent!
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% id = "01HY5R1ZV93GGZ7CPTEPY8CW8K"
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- I actually kind of wish references were more like they are in Rust - basically just pointers but non-null and guaranteed to be aligne
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% id = "01HY5R1ZV9QWHZRJ5V53CVYG5V"
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- anyways, as a final ~~boss~~ bonus of this blog post, I'd like to introduce you to the `x->y` operator (the C one)
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% id = "01HY5R1ZV9AYFWV96FC07WX68G"
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- if you've been programmming C or C++ for a while, you'll know that it's pretty dangerous to just go pointer-[walkin'](https://www.youtube.com/watch?v=d_dLIy2gQGU) with the `->` operator
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```c
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int* third(struct list* first) {
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return &list->next->next->value;
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}
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```
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% id = "01HY5R1ZV9XR75M4TN7H08HYPF"
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+ there's a pretty high chance that using the `third` function will cause a crash for you if there are only two elements in the list.
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% id = "01HY5R1ZV97K8Y4S4V68555MKV"
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- if it doesn't cause a crash, you may have more serious problems to worry about :kamien:
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% id = "01HY5R1ZV9EEN448SB62YMAGZP"
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- but how does it cause a crash if we're taking the reference out of that whole `->` chain? shouldn't taking a reference not cause any reads?
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% id = "01HY5R1ZV977KHP1QDXWY7CTZJ"
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- the secret lies in what the `x->y` operator really does.
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basically, it's just convenience syntax for `(*x).y`.
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% id = "01HY5R1ZV9X8M5T64BD0MZ2WN2"
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- let's start by dismantling the entire pointer access chain into separate expressions:
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```c
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int* third(struct list* first) {
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struct list* second = first->next;
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struct list* third = second->next;
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return &third->value;
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}
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```
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% id = "01HY5R1ZV9PGQMS2A6H5XTWYZX"
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- now let's desugar the `->` operator:
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```c
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int* third(struct list* first) {
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struct list* second = (*first).next;
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struct list* third = (*second).next;
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return &(*third).value;
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}
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```
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% id = "01HY5R1ZV92CZAV13P4KFABTR1"
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- and add some type annotations:
|
||||||
|
```c.types
|
||||||
|
int* third(struct list* first) {
|
||||||
|
struct list* second = (*first).next /*: place(struct list*) */;
|
||||||
|
struct list* third = (*second).next /*: place(struct list*) */;
|
||||||
|
return &(*third).value;
|
||||||
|
}
|
||||||
|
```
|
||||||
|
|
||||||
|
% id = "01HY5R1ZV9671KDJAATWBPGD2C"
|
||||||
|
- and now let's follow it line by line.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZV936BNY9MY4ANCXYH1"
|
||||||
|
- ```c.types
|
||||||
|
struct list* second = (*first).next /*: place(struct list*) */;
|
||||||
|
```
|
||||||
|
first we read the value of the `next` field from the structure pointed to by `first`.
|
||||||
|
assuming `first` is a valid pointer, this shouldn't fail.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZV9VNTRSCFWBW9BCTHJ"
|
||||||
|
- ```c.types
|
||||||
|
struct list* third = (*second).next /*: place(struct list*) */;
|
||||||
|
```
|
||||||
|
but now something bad happens: we don't know if the `second` pointer we just got a `place(T)` from is valid.
|
||||||
|
we offset it by `.next` and implicitly read from it, which is bad!
|
||||||
|
|
||||||
|
% id = "01HY5R1ZV9S50S4MYYQ1Q5P00Z"
|
||||||
|
- at this point there's no point in analyzing the rest of the function - we've hit Undefined Behavior!
|
||||||
|
|
||||||
|
% id = "01HY5R1ZV9A1FS9SRFJBM5NVSR"
|
||||||
|
- the conclusion here is that chaining `x->y` can be really dangerous if you don't check for the validity of each reference.
|
||||||
|
just doing one hop and a reference - `&x->y` - is fine, because we never end up reading from the invalid pointer -
|
||||||
|
it's like doing `&x[1]`.
|
||||||
|
but two hops is where it gets hairy - in `x->y->z`, the `->z` has to _read_ from `x->y` to know the pointer to read from.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZV9VSE2WWH93NCAGRS8"
|
||||||
|
- TODO: in the future I'd like to embed a C compiler here that will desugar all place operations into explicit ones.
|
||||||
|
stay tuned for that!
|
|
@ -6,6 +6,133 @@
|
||||||
% id = "01HRT0DG7VF31P185J898QQH85"
|
% id = "01HRT0DG7VF31P185J898QQH85"
|
||||||
- really there's not much more to it, but I use it for debugging + with it you can get a general feel for how I highlight things in the treehouse
|
- really there's not much more to it, but I use it for debugging + with it you can get a general feel for how I highlight things in the treehouse
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5JFAYBFFT579HF1T4"
|
||||||
|
- design notes
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5V5Q72QGP1RK13H10"
|
||||||
|
- don't do magic: stick to standards and community conventions.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW578NT8G6BTNAN79QK"
|
||||||
|
- like in C, don't highlight uppercase identifiers.
|
||||||
|
those are not special in any way.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5MAS6K7K9QJT4HYQV"
|
||||||
|
- in Rust, we highlight identifiers starting with an uppercase letter, because that's the
|
||||||
|
style convention for user-defined types.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5NC96PA7VDKDVMEPX"
|
||||||
|
- keep it simple.
|
||||||
|
the highlighting doesn't have to be perfect.
|
||||||
|
you know what you're typing.
|
||||||
|
in case of user input, you have a compiler that will highlight the error anyways.
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5R3808RNG6RAPC8H4"
|
||||||
|
- `c`
|
||||||
|
% id = "01HY5R1ZW51JDH26B27ZTGP9JA"
|
||||||
|
- NOTE: this is C23 so you may see some unfamiliar keywords
|
||||||
|
% id = "01HY5R1ZW5DDH54AFNJTFMKZSF"
|
||||||
|
- patterns
|
||||||
|
```c
|
||||||
|
#include <stdio.h>
|
||||||
|
#define SOMETHING_SOMETHING
|
||||||
|
|
||||||
|
// a comment
|
||||||
|
/* a multiline
|
||||||
|
comment */
|
||||||
|
|
||||||
|
function()
|
||||||
|
struct S enum E union U
|
||||||
|
u8'ą' u'g' U'g' L'g'
|
||||||
|
u8"UTF-8" u"UTF-16" U"UTF-32" L"wchar_t"
|
||||||
|
ident
|
||||||
|
|
||||||
|
0b1010'1010 0b1010'1010u 0b1010'1010llu 0b1010'1010wb
|
||||||
|
0xDeadBeef 012345l
|
||||||
|
123ull 127wb
|
||||||
|
3.14159265 3.141592f 1.0e-4d 0xa.dp+2
|
||||||
|
|
||||||
|
. ->
|
||||||
|
++ -- & * + - ~ !
|
||||||
|
/ % << >> < > <= >= == != ^ | && ||
|
||||||
|
? : :: ; ...
|
||||||
|
= *= /= %= += -= <<= >>= &= ^= |=
|
||||||
|
, # ##
|
||||||
|
<: :> <% %> %: %:%:
|
||||||
|
```
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5X2AVZFVHV0QR1J93"
|
||||||
|
- keywords
|
||||||
|
```c
|
||||||
|
alignas alignof auto break case const constexpr continue default do else extern for goto if
|
||||||
|
inline register restrict return sizeof static static_assert switch thread_local typedef typeof
|
||||||
|
typeof_unqual volatile while _Generic _Noreturn
|
||||||
|
|
||||||
|
bool char double float int long short signed struct unsigned union void _Atomic _BitInt _Complex
|
||||||
|
_Decimal128 _Decimal32 _Decimal64 _Imaginary
|
||||||
|
|
||||||
|
nullptr false true
|
||||||
|
```
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5PP1C00NSWAG5FA8B"
|
||||||
|
- sample
|
||||||
|
```c
|
||||||
|
#include <snug/bump.h>
|
||||||
|
|
||||||
|
#include <snug/panic.h>
|
||||||
|
|
||||||
|
void bump_init(struct bump* a, void* slab, i32 size)
|
||||||
|
{
|
||||||
|
a->start = slab;
|
||||||
|
a->ptr = slab + size;
|
||||||
|
#if SNUGGLES_BUMP_TRACKING
|
||||||
|
a->tracker = null;
|
||||||
|
#endif
|
||||||
|
}
|
||||||
|
|
||||||
|
void* bump_try_alloc(struct bump* a, i32 size, const char* what)
|
||||||
|
{
|
||||||
|
// Allocate n bytes and align the pointer to 16 bytes.
|
||||||
|
a->ptr = (void*)((long long)(a->ptr - size) & ~0xF);
|
||||||
|
|
||||||
|
void* addr;
|
||||||
|
// TODO: Because this check is done after the allocation, this will eventually start
|
||||||
|
// overflowing. Not good, but not important either because most allocations
|
||||||
|
// use bump_alloc_or_panic.
|
||||||
|
if (a->ptr < a->start) {
|
||||||
|
addr = null;
|
||||||
|
} else {
|
||||||
|
addr = a->ptr;
|
||||||
|
}
|
||||||
|
|
||||||
|
#if SNUGGLES_BUMP_TRACKING
|
||||||
|
if (a->tracker) {
|
||||||
|
(a->tracker)(addr, size, what);
|
||||||
|
}
|
||||||
|
#endif
|
||||||
|
|
||||||
|
return addr;
|
||||||
|
}
|
||||||
|
|
||||||
|
void* bump_alloc_or_panic(struct bump* a, i32 size, const char* what)
|
||||||
|
{
|
||||||
|
(void)what; // Currently unused, may use for panic message in the future.
|
||||||
|
|
||||||
|
void* p = bump_try_alloc(a, size, what);
|
||||||
|
b32 allocation_succeeded = p != 0;
|
||||||
|
ASSERT(allocation_succeeded, "out of memory");
|
||||||
|
return p;
|
||||||
|
}
|
||||||
|
```
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5Y28GDH0YX46WV9KN"
|
||||||
|
- `.types`
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW5KYY6VCKWBHN1GF10"
|
||||||
|
- patterns
|
||||||
|
```c.types
|
||||||
|
x /*: int */
|
||||||
|
```
|
||||||
|
|
||||||
% id = "01HRT0DG7VN5TH971H7W8AT8YY"
|
% id = "01HRT0DG7VN5TH971H7W8AT8YY"
|
||||||
- `javascript`
|
- `javascript`
|
||||||
|
|
||||||
|
|
|
@ -10,6 +10,14 @@
|
||||||
|
|
||||||
[read][page:programming/blog/tairu]
|
[read][page:programming/blog/tairu]
|
||||||
|
|
||||||
|
% id = "01HY5R1ZW2PYZSSP2J2KAA23DA"
|
||||||
|
- I recently got a question from my someone telling me they doesn't understand why `*x` does not read from the pointer `x` when on the left-hand side of an assignment.
|
||||||
|
and that made me think,
|
||||||
|
|
||||||
|
### what's up with `*x` not always meaning the same thing in different contexts?
|
||||||
|
|
||||||
|
[read][page:programming/blog/lvalues]
|
||||||
|
|
||||||
% id = "01HV1DGFHZ65GJVQRSREKR67J9"
|
% id = "01HV1DGFHZ65GJVQRSREKR67J9"
|
||||||
- I've been thinking recently how cool it is to be able to single-step into Unreal Engine's source code and edit it while you're working with it, and how uncool it is that I can't do the same thing easily in the Rust world.
|
- I've been thinking recently how cool it is to be able to single-step into Unreal Engine's source code and edit it while you're working with it, and how uncool it is that I can't do the same thing easily in the Rust world.
|
||||||
|
|
||||||
|
|
|
@ -108,6 +108,13 @@ button {
|
||||||
line-height: 1.5;
|
line-height: 1.5;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
pre,
|
||||||
|
code,
|
||||||
|
kbd,
|
||||||
|
button {
|
||||||
|
font-size: 100%;
|
||||||
|
}
|
||||||
|
|
||||||
:root {
|
:root {
|
||||||
--recursive-mono: 0.0;
|
--recursive-mono: 0.0;
|
||||||
--recursive-casl: 1.0;
|
--recursive-casl: 1.0;
|
||||||
|
@ -792,6 +799,15 @@ th-literate-program[data-mode="output"] {
|
||||||
color: var(--error-color);
|
color: var(--error-color);
|
||||||
text-decoration: wavy underline;
|
text-decoration: wavy underline;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
&.hidden {
|
||||||
|
display: none;
|
||||||
|
}
|
||||||
|
|
||||||
|
&.type-hint {
|
||||||
|
color: var(--syntax-comment);
|
||||||
|
font-size: 80%;
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
.th-syntax-highlighting {
|
.th-syntax-highlighting {
|
||||||
|
|
98
static/syntax/c.json
Normal file
98
static/syntax/c.json
Normal file
|
@ -0,0 +1,98 @@
|
||||||
|
{
|
||||||
|
"patterns": [
|
||||||
|
{
|
||||||
|
"regex": "#include (<.+?>)",
|
||||||
|
"is": { "default": "keyword1", "captures": ["string"] }
|
||||||
|
},
|
||||||
|
{ "regex": "#[a-zA-Z0-9_]+", "is": "keyword1" },
|
||||||
|
{ "regex": "\\/\\/.*", "is": "comment" },
|
||||||
|
{
|
||||||
|
"regex": "\\/\\*.*?\\*\\/",
|
||||||
|
"flags": ["dotMatchesNewline"],
|
||||||
|
"is": "comment"
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "[a-zA-Z_][a-zA-Z0-9_]*(\\()",
|
||||||
|
"is": { "default": "function", "captures": ["default"] }
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "(struct|enum|union)\\s+([a-zA-Z_][a-zA-Z0-9_]*)",
|
||||||
|
"is": {
|
||||||
|
"default": "default",
|
||||||
|
"captures": ["identifier", "keyword2"]
|
||||||
|
}
|
||||||
|
},
|
||||||
|
{ "regex": "(u8|u|U|L)'(\\\\'|[^'])'", "is": "string" },
|
||||||
|
{ "regex": "(u8|u|U|L)\"(\\\\\"|[^\"])*\"", "is": "string" },
|
||||||
|
{ "regex": "[a-zA-Z_][a-zA-Z0-9_]*", "is": "identifier" },
|
||||||
|
{ "regex": "0[bB][01']+[uUlLfFlLdDwWbB]*", "is": "literal" },
|
||||||
|
{
|
||||||
|
"regex": "0[xX][0-9a-fA-F']+(\\.[0-9a-fA-F']*([pP][-+]?[0-9a-fA-F']+)?)?+[uUlLwWbB]*",
|
||||||
|
"is": "literal"
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "[0-9']+(\\.[0-9']*([eE][-+]?[0-9']+)?)?[uUlLfFlLdDwWbB]*",
|
||||||
|
"is": "literal"
|
||||||
|
},
|
||||||
|
{ "regex": "[+=/*^%<>!~|&\\.?:#-]+", "is": "operator" },
|
||||||
|
{ "regex": "[,;]", "is": "punct" }
|
||||||
|
],
|
||||||
|
"keywords": {
|
||||||
|
"alignas": { "into": "keyword1" },
|
||||||
|
"alignof": { "into": "keyword1" },
|
||||||
|
"auto": { "into": "keyword1" },
|
||||||
|
"break": { "into": "keyword1" },
|
||||||
|
"case": { "into": "keyword1" },
|
||||||
|
"const": { "into": "keyword1" },
|
||||||
|
"constexpr": { "into": "keyword1" },
|
||||||
|
"continue": { "into": "keyword1" },
|
||||||
|
"default": { "into": "keyword1" },
|
||||||
|
"do": { "into": "keyword1" },
|
||||||
|
"else": { "into": "keyword1" },
|
||||||
|
"extern": { "into": "keyword1" },
|
||||||
|
"for": { "into": "keyword1" },
|
||||||
|
"goto": { "into": "keyword1" },
|
||||||
|
"if": { "into": "keyword1" },
|
||||||
|
"inline": { "into": "keyword1" },
|
||||||
|
"register": { "into": "keyword1" },
|
||||||
|
"restrict": { "into": "keyword1" },
|
||||||
|
"return": { "into": "keyword1" },
|
||||||
|
"sizeof": { "into": "keyword1" },
|
||||||
|
"static": { "into": "keyword1" },
|
||||||
|
"static_assert": { "into": "keyword1" },
|
||||||
|
"switch": { "into": "keyword1" },
|
||||||
|
"thread_local": { "into": "keyword1" },
|
||||||
|
"typedef": { "into": "keyword1" },
|
||||||
|
"typeof": { "into": "keyword1" },
|
||||||
|
"typeof_unqual": { "into": "keyword1" },
|
||||||
|
"volatile": { "into": "keyword1" },
|
||||||
|
"while": { "into": "keyword1" },
|
||||||
|
"_Generic": { "into": "keyword1" },
|
||||||
|
"_Noreturn": { "into": "keyword1" },
|
||||||
|
|
||||||
|
"bool": { "into": "keyword2" },
|
||||||
|
"char": { "into": "keyword2" },
|
||||||
|
"double": { "into": "keyword2" },
|
||||||
|
"enum": { "into": "keyword2" },
|
||||||
|
"float": { "into": "keyword2" },
|
||||||
|
"int": { "into": "keyword2" },
|
||||||
|
"long": { "into": "keyword2" },
|
||||||
|
"short": { "into": "keyword2" },
|
||||||
|
"signed": { "into": "keyword2" },
|
||||||
|
"struct": { "into": "keyword2" },
|
||||||
|
"unsigned": { "into": "keyword2" },
|
||||||
|
"union": { "into": "keyword2" },
|
||||||
|
"void": { "into": "keyword2" },
|
||||||
|
"_Atomic": { "into": "keyword2" },
|
||||||
|
"_BitInt": { "into": "keyword2" },
|
||||||
|
"_Complex": { "into": "keyword2" },
|
||||||
|
"_Decimal128": { "into": "keyword2" },
|
||||||
|
"_Decimal32": { "into": "keyword2" },
|
||||||
|
"_Decimal64": { "into": "keyword2" },
|
||||||
|
"_Imaginary": { "into": "keyword2" },
|
||||||
|
|
||||||
|
"nullptr": { "into": "literal" },
|
||||||
|
"false": { "into": "literal" },
|
||||||
|
"true": { "into": "literal" }
|
||||||
|
}
|
||||||
|
}
|
106
static/syntax/c.types.json
Normal file
106
static/syntax/c.types.json
Normal file
|
@ -0,0 +1,106 @@
|
||||||
|
{
|
||||||
|
"patterns": [
|
||||||
|
{
|
||||||
|
"regex": "#include (<.+?>)",
|
||||||
|
"is": { "default": "keyword1", "captures": ["string"] }
|
||||||
|
},
|
||||||
|
{ "regex": "#[a-zA-Z0-9_]+", "is": "keyword1" },
|
||||||
|
{ "regex": "\\/\\/.*", "is": "comment" },
|
||||||
|
{
|
||||||
|
"regex": "\\/\\*((?::|->).*?)\\s*\\*\\/",
|
||||||
|
"flags": ["dotMatchesNewline"],
|
||||||
|
"is": {
|
||||||
|
"default": "hidden",
|
||||||
|
"captures": ["type-hint"]
|
||||||
|
}
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "\\/\\*.*?\\*\\/",
|
||||||
|
"flags": ["dotMatchesNewline"],
|
||||||
|
"is": "comment"
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "[a-zA-Z_][a-zA-Z0-9_]*(\\()",
|
||||||
|
"is": { "default": "function", "captures": ["default"] }
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "(struct|enum|union)\\s+([a-zA-Z_][a-zA-Z0-9_]*)",
|
||||||
|
"is": {
|
||||||
|
"default": "default",
|
||||||
|
"captures": ["identifier", "keyword2"]
|
||||||
|
}
|
||||||
|
},
|
||||||
|
{ "regex": "(u8|u|U|L)'(\\\\'|[^'])'", "is": "string" },
|
||||||
|
{ "regex": "(u8|u|U|L)\"(\\\\\"|[^\"])*\"", "is": "string" },
|
||||||
|
{ "regex": "[a-zA-Z_][a-zA-Z0-9_]*", "is": "identifier" },
|
||||||
|
{ "regex": "0[bB][01']+[uUlLfFlLdDwWbB]*", "is": "literal" },
|
||||||
|
{
|
||||||
|
"regex": "0[xX][0-9a-fA-F']+(\\.[0-9a-fA-F']*([pP][-+]?[0-9a-fA-F']+)?)?+[uUlLwWbB]*",
|
||||||
|
"is": "literal"
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"regex": "[0-9']+(\\.[0-9']*([eE][-+]?[0-9']+)?)?[uUlLfFlLdDwWbB]*",
|
||||||
|
"is": "literal"
|
||||||
|
},
|
||||||
|
{ "regex": "[+=/*^%<>!~|&\\.?:#-]+", "is": "operator" },
|
||||||
|
{ "regex": "[,;]", "is": "punct" }
|
||||||
|
],
|
||||||
|
"keywords": {
|
||||||
|
"alignas": { "into": "keyword1" },
|
||||||
|
"alignof": { "into": "keyword1" },
|
||||||
|
"auto": { "into": "keyword1" },
|
||||||
|
"break": { "into": "keyword1" },
|
||||||
|
"case": { "into": "keyword1" },
|
||||||
|
"const": { "into": "keyword1" },
|
||||||
|
"constexpr": { "into": "keyword1" },
|
||||||
|
"continue": { "into": "keyword1" },
|
||||||
|
"default": { "into": "keyword1" },
|
||||||
|
"do": { "into": "keyword1" },
|
||||||
|
"else": { "into": "keyword1" },
|
||||||
|
"extern": { "into": "keyword1" },
|
||||||
|
"for": { "into": "keyword1" },
|
||||||
|
"goto": { "into": "keyword1" },
|
||||||
|
"if": { "into": "keyword1" },
|
||||||
|
"inline": { "into": "keyword1" },
|
||||||
|
"register": { "into": "keyword1" },
|
||||||
|
"restrict": { "into": "keyword1" },
|
||||||
|
"return": { "into": "keyword1" },
|
||||||
|
"sizeof": { "into": "keyword1" },
|
||||||
|
"static": { "into": "keyword1" },
|
||||||
|
"static_assert": { "into": "keyword1" },
|
||||||
|
"switch": { "into": "keyword1" },
|
||||||
|
"thread_local": { "into": "keyword1" },
|
||||||
|
"typedef": { "into": "keyword1" },
|
||||||
|
"typeof": { "into": "keyword1" },
|
||||||
|
"typeof_unqual": { "into": "keyword1" },
|
||||||
|
"volatile": { "into": "keyword1" },
|
||||||
|
"while": { "into": "keyword1" },
|
||||||
|
"_Generic": { "into": "keyword1" },
|
||||||
|
"_Noreturn": { "into": "keyword1" },
|
||||||
|
|
||||||
|
"bool": { "into": "keyword2" },
|
||||||
|
"char": { "into": "keyword2" },
|
||||||
|
"double": { "into": "keyword2" },
|
||||||
|
"enum": { "into": "keyword2" },
|
||||||
|
"float": { "into": "keyword2" },
|
||||||
|
"int": { "into": "keyword2" },
|
||||||
|
"long": { "into": "keyword2" },
|
||||||
|
"short": { "into": "keyword2" },
|
||||||
|
"signed": { "into": "keyword2" },
|
||||||
|
"struct": { "into": "keyword2" },
|
||||||
|
"unsigned": { "into": "keyword2" },
|
||||||
|
"union": { "into": "keyword2" },
|
||||||
|
"void": { "into": "keyword2" },
|
||||||
|
"_Atomic": { "into": "keyword2" },
|
||||||
|
"_BitInt": { "into": "keyword2" },
|
||||||
|
"_Complex": { "into": "keyword2" },
|
||||||
|
"_Decimal128": { "into": "keyword2" },
|
||||||
|
"_Decimal32": { "into": "keyword2" },
|
||||||
|
"_Decimal64": { "into": "keyword2" },
|
||||||
|
"_Imaginary": { "into": "keyword2" },
|
||||||
|
|
||||||
|
"nullptr": { "into": "literal" },
|
||||||
|
"false": { "into": "literal" },
|
||||||
|
"true": { "into": "literal" }
|
||||||
|
}
|
||||||
|
}
|
Loading…
Reference in a new issue