id stringlengths 16 145 | text stringlengths 1 179k | title stringclasses 1
value |
|---|---|---|
r_std_hashmap/614907_24_0.txt | So pretty much what I want to do is, I create a list of those posts, and then
I want to create a file with a specific format. This is why I can have the
list of all symbols (tags) seen across the different posts.
Now I guess I have 2 choices:
1. (feels more natural) the posts own the strings and the OrderedStrings... | |
r_std_hashmap/36349_84_0.txt | Code
Link | |
r_std_hashmap/36349_78_0.txt | Answer selected by warriorstar-orion
Sign up for free to join this conversation on GitHub . Already have an
account? Sign in to comment | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_17_0.txt | and adding a ` #[derive(FromHashmap)] ` to the struct's declaration.
To check out the generated code, give rustc the arguments ` -Z unstable-
options --pretty=expanded ` . This will expand all the macros in the source
and output it to the console. Running ` cargo rustc -- -Z unstable-options
--pretty=expanded > expand... | |
r_std_hashmap/enum.Type.html5_31_0.txt | source
#### pub fn from_texpr ( t: Spanned < TypeExpr >, t_context:
TypeContext , t_decs: &Dag< HashMap < String , Type , RandomState >,
String , u32 > ) -> Result < Type , Spanned < Error >> | |
r_std_hashmap/enum.Type.html5_72_0.txt | #### fn into (self) -> U
Calls ` U::from(self) ` . | |
r_std_hashmap/36349_56_0.txt | *
# {{editor}}'s edit | |
r_std_hashmap/enum.Type.html5_81_0.txt | source §
### impl<T> ToString for T where T: Display \+ ? Sized , | |
r_std_hashmap/614907_21_0.txt | Ok, so let's assume you need that ` Vec ` Now, where's that ` BTreeSet ` from?
Whey are there ` &str ` in it? Are they ` &'static str ` or are they borrowing
from somewhere else? That should very much inform the further choices.
Also, forget about using ` str ` directly, you can't have a ` Vec<str> ` .
Here is a vers... | |
r_std_hashmap/enum.Type.html5_82_0.txt | source §
#### default fn to_string (&self) -> String | |
r_std_hashmap/36349_16_0.txt | Fund open source developers
* The ReadME Project | |
r_std_hashmap/enum.Type.html5_7_0.txt | * from_enumdef
* from_structdef
* from_texpr
* from_typedef
* is_stable
* sub_generic
* well_formed
### Trait Implementations | |
r_std_hashmap/36349_37_0.txt | edited
* | |
r_std_hashmap/enum.Type.html5_20_0.txt | ### List( Box < Type , Global >)
§ | |
r_std_hashmap/36349_29_0.txt | * Notifications
* Fork 665
* Star 11.1k
* Code
* Issues 184
* Pull requests 49
* Discussions
* Actions
* Projects 1
* Security
* Insights | |
r_std_hashmap/614907_47_0.txt | agiuliano June 24, 2021, 8:37pm 15
Yeah I guess if I extract the read from file function it can work. My problem
here is probably around the encapsulation..
What I want to do is that OrderedStrings can be created from the outside world
only with a treeset (to enforce the strings are in order) but then inside the
i... | |
r_std_hashmap/enum.Type.html5_73_0.txt | That is, this conversion is whatever the implementation of ` From <T> for U `
chooses to do.
source § | |
r_std_hashmap/enum.Type.html5_12_0.txt | source · [ − ]
pub enum Type {
Show 16 variants Unit,
Int,
Float,
String,
Bool,
Tuple(Vec<Box<Type, Global>, Global>),
List(Box<Type, Global>),
Function(Box<Type, Global>, Box<Type, Global>),
Delay(Box<Type, Global>),
Stab... | |
r_std_hashmap/36349_62_0.txt |
struct BarWrapper {
foo: Py<FooWrapper>,
key: String,
index: usize,
}
impl BarWrapper {
fn value(&self, py: Python<'_>) -> &Bar {
&self.foo.borrow(py).0[&self.key][self.index]
}
}
(I have not compiled this, so it will most likely trigger some com... | |
r_std_hashmap/614907_14_0.txt | 3 Likes
agiuliano June 24, 2021, 1:09pm 5 | |
r_std_hashmap/enum.Type.html5_45_0.txt | source §
### impl Display for Type | |
r_std_hashmap/614907_7_0.txt | 1. ` index_by_symbol ` in the struct should probably be ` &str ` to get a reference, but then I get a suggestion to use lifetimes..
2. in the new method I accept an ordered set of strings (where I don't take ownership) that makes things complex when I want to use plain ` str `
Cerber-Ursi June 24, 2021, 11:44am ... | |
r_std_hashmap/36349_34_0.txt | Answered by adamreichold Return to top
Discussion options | |
r_std_hashmap/614907_4_0.txt | Now what I'm bugged with is ownership.. since the vector and hashmap contain
the exact same string, I'd like to store them only once in memory.
Do you have any suggestion on how to do it? | |
r_std_hashmap/enum.Type.html5_78_0.txt | #### fn clone_into (&self, target: &mut T )
Uses borrowed data to replace owned data, usually by cloning. Read more | |
r_std_hashmap/r_std_hashmap_2_2.txt | %0A++++\(%22Venus%22,+0.7\),%0A++++\(%22Earth%22,+1.0\),%0A++++\(%22Mars%22,+1.5\),%0A%5D\);%0A%7D&edition=2021)
` HashMap ` implements an ` Entry ` API , which allows for complex methods
of getting, setting, updating and removing keys and their values:
use std::collections::HashMap;
// type ... | |
r_std_hashmap/614907_10_0.txt | This combination of requirements hints that you probably want to use ` Rc<str>
` (or ` Arc<str> ` , if you need ` Send ` / ` Sync ` ) - a smart pointer for
shared immutable ownership.
5 Likes | |
r_std_hashmap/enum.Type.html5_3_0.txt | * Versions
* * Platform
* i686-unknown-linux-gnu
* x86_64-apple-darwin
* x86_64-pc-windows-msvc
* x86_64-unknown-linux-gnu
* Feature flags
* Rust
* About docs.rs
* Privacy policy
* Rust website
* The Book
* Standard Library API Reference
* Rust by Exam... | |
r_std_hashmap/r_std_hashmap_8_0.txt | 1.6.0 · [ source ](../../src/std/collections/hash/map.rs.html#618-620)
#### pub fn drain (&mut self) -> [ Drain ](hash_map/struct.Drain.html
"struct std::collections::hash_map::Drain") <'_, K, V> â
Clears the map, returning all key-value pairs as an iterator. Keeps the
allocated memory for reuse.
If the retur... | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_15_0.txt |
#![recursion_limit = "128"]
extern crate proc_macro;
extern crate syn;
#[macro_use]
extern crate quote;
use proc_macro::TokenStream;
use syn::{Ident, VariantData};
#[proc_macro_derive(FromHashmap)]
pub fn from_hashmap(input: TokenStream) -> TokenStream {
... | |
r_std_hashmap/614907_61_0.txt | Topic | | Replies | Views | Activity
---|---|---|---|---
Structs, closures, references and Strings, oh my! help | 6 | 1113 | January 12, 2023
A little confused about String vs str, ownership, and Copy trait help | 5 | 1342 | March 16, 2022
Rust how to convert vector of raw strings to str... | |
r_std_hashmap/enum.Type.html5_89_0.txt | #### type Error = <U as TryFrom <T>>:: Error
The type returned in the event of a conversion error. | |
r_std_hashmap/enum.Type.html5_85_0.txt | #### type Error = Infallible
The type returned in the event of a conversion error. | |
r_std_hashmap/614907_11_0.txt | KillTheMule June 24, 2021, 12:08pm 3
Why do you need the extra ` Vec<String> ` ? You can iterate over the keys of
the ` HashMap ` just as well. | |
r_std_hashmap/36349_72_0.txt | *
# {{title}} | |
r_std_hashmap/enum.Type.html5_29_0.txt | ### Enum( HashMap < String , Option < Box < Type , Global >>,
RandomState >)
## Implementations § | |
r_std_hashmap/614907_31_0.txt | In the scenario you described I think Option 1 makes much more sense. The
shape of the code will be like
let posts = get_stuff_from_db();
let ordered_strings = Odered_Strings::from_posts(&posts); // borrowing from the above
... //do stuff with ordered strings
// ordered_strings... | |
r_std_hashmap/36349_32_0.txt | warriorstar-orion asked this question in Questions
Sharing Rust structs in foreign libraries / Writing complex wrapper classes
#3634 | |
r_std_hashmap/r_std_hashmap_11_0.txt | 1.57.0 · [ source ](../../src/std/collections/hash/map.rs.html#783-785)
#### pub fn try_reserve (&mut self, additional: [ usize
](../primitive.usize.html) ) -> [ Result ](../result/enum.Result.html "enum
std::result::Result") < [ () ](../primitive.unit.html) , [ TryReserveError
](struct.TryReserveError.html "stru... | |
r_std_hashmap/614907_54_0.txt | agiuliano June 27, 2021, 10:14am 18
agiuliano: | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_18_0.txt |
...
impl FromHashmap<SimBrokerSettings> for SimBrokerSettings {
fn from_hashmap(mut hm:
::std::collections::HashMap<String, String>)
-> SimBrokerSettings {
let mut settings = SimBrokerSettings::default();
match hm.entry(String::... | |
r_std_hashmap/36349_41_0.txt | Dec 8, 2023
\- | |
r_std_hashmap/36349_46_0.txt | My understanding is that by assigning a bar to a python local, we're crossing
this boundary where the native Bar struct needs to be owned by both the ` vec
` inside the Foo's ` IndexMap ` , as well as by Python, because the BarWrapper
could exist forever and be assigned to as many locals as we want. It seems
like ` PyC... | |
r_std_hashmap/614907_48_0.txt | So pretty much when using the struct impl you can:
* create from an ordered set
* flush on a buffer ` self `
* read from a buffer to recreate the struct | |
r_std_hashmap/enum.Type.html5_14_0.txt | ### Unit
§ | |
r_std_hashmap/36349_36_0.txt | Something went wrong.
Quote reply | |
r_std_hashmap/enum.Type.html5_13_0.txt | ## Variants §
§ | |
r_std_hashmap/r_std_hashmap_17_1.txt | #tymethod.from) (t: T) -> T
Returns the argument unchanged.
[ source ](../../src/core/convert/mod.rs.html#747-749) §
### impl<T, U> [ Into ](../convert/trait.Into.html "trait
std::convert::Into") <U> for T
where U: [ From ](../convert/trait.From.html "trait std::convert::From") <T>,
[ source ](../../src/core/con... | |
r_std_hashmap/enum.Type.html5_53_0.txt | §
### impl RefUnwindSafe for Type | |
r_std_hashmap/614907_8_0.txt | agiuliano:
> since the vector and hashmap contain the exact same string, I'd like to
> store them only once in memory. | |
r_std_hashmap/enum.Type.html5_87_0.txt | Performs the conversion.
source § | |
r_std_hashmap/enum.Type.html5_22_0.txt | ### Delay( Box < Type , Global >)
§ | |
r_std_hashmap/36349_3_0.txt | Automate any workflow
* Packages | |
r_std_hashmap/36349_35_0.txt | *
# {{title}} | |
r_std_hashmap/enum.Type.html5_80_0.txt | §
#### fn to_sample_ (self) -> U | |
r_std_hashmap/614907_49_0.txt | that's the reason why I wanted to have the read inside.. I've noticed that
rust was bringing me to push stuff out, my only fear is that often it's just
moving the problem one step away but it will still be there, so that's why I
wonder whether I'm missing something (I'm sure I am)
KillTheMule June 24, 2021, 8:58pm 1... | |
r_std_hashmap/36349_80_0.txt | Questions
Labels | |
r_std_hashmap/r_std_hashmap_2_1.txt | res of Huckleberry Finn".to_string(),
"My favorite book.".to_string(),
);
book_reviews.insert(
"Grimms' Fairy Tales".to_string(),
"Masterpiece.".to_string(),
);
book_reviews.insert(
"Pride and Prejudice".to_string(),
"Very enjoyable.".to_string(),
);
book_... | |
r_std_hashmap/enum.Type.html5_57_0.txt | §
### impl UnwindSafe for Type | |
r_std_hashmap/enum.Type.html5_33_0.txt | source
#### pub fn from_structdef ( id: String , params: Vec < String ,
Global >, fields: Vec <( String , Spanned < TypeExpr >), Global >,
t_decs: &Dag< HashMap < String , Type , RandomState >, String , u32
> ) -> Result < Type , Spanned < Error >> | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_6_0.txt | Then I read about Rust's new procedural macros. They provide a way to generate
new code at compile-time, making it possible to do things like automatically
derive the ` Serialize ` and ` Deserialize ` in serde . I decided to create
a ` FromHashmap ` trait backed by a procedural macro which would allow me to
automatic... | |
r_std_hashmap/enum.Type.html5_6_0.txt | * Bool
* Delay
* Enum
* Fix
* FixVar
* Float
* Function
* Generic
* GenericVar
* Int
* List
* Stable
* String
* Struct
* Tuple
* Unit
### Methods | |
r_std_hashmap/36349_91_0.txt | 👍 1 reacted with thumbs up emoji 👎 1 reacted with thumbs down emoji 😄 1
reacted with laugh emoji 🎉 1 reacted with hooray emoji 😕 1 reacted with
confused emoji ❤️ 1 reacted with heart emoji 🚀 1 reacted with rocket
emoji 👀 1 reacted with eyes emoji
## Footer | |
r_std_hashmap/enum.Type.html5_55_0.txt | §
### impl Sync for Type | |
r_std_hashmap/r_std_hashmap_13_0.txt | 1.40.0 · [ source ](../../src/std/collections/hash/map.rs.html#903-909)
#### pub fn get_key_value <Q>(&self, k: [ &Q ](../primitive.reference.html)
) -> [ Option ](../option/enum.Option.html "enum std::option::Option") <( [ &K
](../primitive.reference.html) , [ &V ](../primitive.reference.html) )>
where K: [ Bor... | |
r_std_hashmap/enum.Type.html5_30_0.txt | source §
### impl Type | |
r_std_hashmap/36349_74_0.txt | ####
adamreichold Dec 19, 2023 | |
r_std_hashmap/36349_4_0.txt | Host and manage packages
* Security | |
r_std_hashmap/enum.Type.html5_38_0.txt | ## Trait Implementations §
source § | |
r_std_hashmap/enum.Type.html5_83_0.txt | Converts the given value to a ` String ` . Read more
source § | |
r_std_hashmap/enum.Type.html5_42_0.txt | Performs copy-assignment from ` source ` . Read more
source § | |
r_std_hashmap/r_std_hashmap_10_0.txt | 1.9.0 · [ source ](../../src/std/collections/hash/map.rs.html#728-730)
#### pub fn hasher (&self) -> [ &S ](../primitive.reference.html)
Returns a reference to the mapâs [ ` BuildHasher `
](../hash/trait.BuildHasher.html "trait std::hash::BuildHasher") .
##### § Examples
use std::collections... | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_14_0.txt | For each of the elements of the vectors interpolated inside the repetition
block, the entire inner part of the repetition block is inserted into the
code. In the test, the ` ,* ` at the end tells Quote to insert a comma as a
separator, very similar to ` .join() ` .
So now we have code that parses the input struct into... | |
r_std_hashmap/36349_76_0.txt | Yes, if the ` Bar ` are created in standalone manner, the above seems like a
good approach. Alternatively, you could limit creation of ` Bar ` from Python
to methods on ` FooWrapper ` which would take care of creation and insertion
as a single operation (from Python's point of view).
---
Beta Was this translati... | |
r_std_hashmap/enum.Type.html5_15_0.txt | ### Int
§ | |
r_std_hashmap/enum.Type.html5_32_0.txt | source
#### pub fn from_typedef ( id: String , params: Vec < String , Global
>, t: Spanned < TypeExpr >, t_decs: &Dag< HashMap < String , Type ,
RandomState >, String , u32 >, path: & Vec < String , Global > ) ->
Result < Type , Spanned < Error >> | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_8_0.txt | It requires that structs that implement it also implement the `
std::default::Default ` trait so that defaults can be used if the provided
HashMap doesn't contain all the necessary values.
Since procedural macros must reside in their own special crate, I created a
new one inside my crate's root directory (at the same ... | |
r_std_hashmap/36349_61_0.txt | > You can see the "foreign" structs are:
Those structures do not support shared ownership (not even in Rust) and hence
you cannot use that on language level. You would would have to introduce
something like ` Arc ` or our own ` Py ` smart pointer into the mix so that
you would store e.g. ` HashMap<String, Vec<Arc<Ba... | |
r_std_hashmap/enum.Type.html5_66_0.txt | source §
### impl<T> From <T> for T | |
r_std_hashmap/614907_56_0.txt |
let hello_var = "hello"
` hello_var ` is a reference to a String that is held on the stack (because
it's not a String but a str).. should I be thinking to have a str instead? | |
r_std_hashmap/36349_57_0.txt | {{actor}} deleted this content .
# {{editor}}'s edit | |
r_std_hashmap/614907_16_0.txt | > Why do you need the extra ` Vec<String> ` ? You can iterate over the keys of
> the ` HashMap ` just as well.
I know I can but that vector is ordered.. so I need to access the strings by
index, and the index by strings. You can see that as if I have 2 maps: | |
r_std_hashmap/36349_26_0.txt | Cancel Create saved search
Sign in | |
r_std_hashmap/36349_81_0.txt | None yet
2 participants | |
r_std_hashmap/614907_2_0.txt | Hi all, as I'm playing with Rust, I'm facing some of the typical (I hope)
problems with borrowing especially when handling strings.
Here's my problem: say I want to have a struct of this shape | |
r_std_hashmap/36349_19_0.txt | Search or jump to...
# Search code, repositories, users, issues, pull requests... | |
r_std_hashmap/enum.Type.html5_9_0.txt | * RefUnwindSafe
* Send
* Sync
* Unpin
* UnwindSafe
### Blanket Implementations | |
r_std_hashmap/614907_57_0.txt | Cerber-Ursi June 27, 2021, 10:21am 19
agiuliano: | |
r_std_hashmap/36349_48_0.txt | 1 You must be logged in to vote
All reactions | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_16_0.txt | Back in the original code, using the procedural macro is as simple as adding a
` from_hashmap = { path = "from_hashmap" } ` line to the crate's Cargo.toml,
importing it with
#[macro_use]
extern crate from_hashmap; | |
r_std_hashmap/enum.Type.html5_52_0.txt | ### impl StructuralPartialEq for Type
## Auto Trait Implementations § | |
r_std_hashmap/r_std_hashmap_3_0.txt | 1.7.0 (const: [ unstable ](https://github.com/rust-lang/rust/issues/102575
"Tracking issue for const_collections_with_hasher") ) · [ source
](../../src/std/collections/hash/map.rs.html#283-285)
#### pub fn with_hasher (hash_builder: S) -> [ HashMap
](hash_map/struct.HashMap.html "struct std::collections::hash_map... | |
r_std_hashmap/36349_47_0.txt |
#[pyclass]
struct FooWrapper {
foo: foreign::Foo,
bars: PyDict<PyList<BarWrapper>>,
}
#[pymethods]
impl FooWrapper {
#[new]
fn new() -> Self {
// Remove all the elements from foo.mapping so they can be owned by the wrapper/pylist/pydict
... | |
r_std_hashmap/36349_64_0.txt | All reactions
2 replies | |
r_std_hashmap/614907_25_0.txt | Option 1 has the advantage that is clear that the main struct owns all the
data, and uses the other structs to just create a projected view. However to
do that I have to use lifetimes (maybe I'm too newbie and that's what you end
up doing most of the cases)
Option 2 instead is nice in a way because I can destruct my m... | |
r_std_hashmap/writing-a-hashmap-to-struct-procedural-macro-in-rust8_10_0.txt | The next step is to get get a list of all the fields of the provided struct.
These are represented as Idents and can be found deep within the AST. This
code unpacks the AST, makes sure that what we're given is actually a standard,
non-tuple struct, and puts all of the field names into a vector:
// crea... | |
r_std_hashmap/614907_53_0.txt |
fn main() {
let point = Point { x: 1, y: 2 };
let serialized = serde_json::to_string(&point).unwrap();
println!("serialized = {}", serialized);
let deserialized: Point = serde_json::from_str(&serialized).unwrap();
println!("deserialized = {:?}", deserializ... | |
r_std_hashmap/36349_68_0.txt | warriorstar-orion Dec 19, 2023
Author | |
r_std_hashmap/614907_51_0.txt | Yeah in Rust you want to push ownership of things high up in the scope tree.
If you don't want to do that explicitely, you might want to think about a top-
level wrapper type that users interact with that can own things. As an entry-
point, the user would construct the top-level type with the necessary data
(database c... | |
r_std_hashmap/enum.Type.html5_56_0.txt | §
### impl Unpin for Type |
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