Comments (2)
I am guessing you have some sort of expression type which is represented as an enum like
enum Expr {
Int(i64),
Identifier(String),
}
If so you can just use the map parser to make them return the the Expr type
choice([env.integer().map(Expr::Int), env.identifier().map(Expr::Identifier)])
Unfortunately you will encounter another problem when you do this as each parser needs to have the same type as well as they are stored in an array which necessitates that all elements have the same type. For small number of alternations the or which allows the parsers to have distinct types as long as they all have the same return type.
For the choice parser it is however possible to cast each of the parser to a trait object which makes sure that they are all the same type.
choice::<&mut [&mut Parser<Input=InputType, Output=Expr>]>(&mut [
&mut env.integer().map(Expr::Int),
&mut env.identifier().map(Expr::Identifier)
])
You can see exactly how I do it in the parser I made for embed_lang here though there is some extra complexity there as well to inject location in the expression as well.
from combine.
Thank you for the detailed reply. As for me, this issue can now be closed.
from combine.
Related Issues (20)
- Publishing 4.6.1? HOT 1
- choice! returns an error when one of its parsers would be successful HOT 2
- Throw stream errors HOT 5
- DateTime parser HOT 1
- take_until_bytes() and partial parsing HOT 2
- Is there a way to get `Stream<Token=char>` from `io::Read`? HOT 1
- Tools for debugging recursion problems? HOT 4
- Some issue with error reporting
- Errors include unprintable or awkwardly printed characters. HOT 6
- `expected` error strings always quote what was expected, even if it isn't a literal HOT 3
- How about offset into some data? HOT 3
- Outdated tutorial HOT 1
- Native/abstracted sub-parsers HOT 6
- XML parsing for React.js to Solid.js conversion HOT 4
- Comparison with LALRPOP
- Unbounded mutual recursion in Parser impl HOT 3
- Adivce on reducing code size in WASM target HOT 7
- Docs unclear whether `parser!` should be used on nightly rust HOT 2
- Parse `std::process::Child` stdout
- Successful parser will not clear the error stack HOT 1
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from combine.