Trait Frontend

Source

pub trait Frontend {
    // Required methods
    fn extensions(&self) -> &'static [&'static str];
    fn elaboration_defaults(&self) -> ElaborationConfig;
    fn parse(
        &self,
        input: &str,
        base_path: &Path,
        opener: &Opener,
    ) -> Result<HIR, Box<dyn Error>>;
}

Expand description

A file-format frontend that produces a resolved HIR.

Implement this trait to add support for a new input format. The CLI uses crate::frontend_for_extension to select the appropriate frontend at runtime based on the file extension of the source file being loaded.

§Example

use doppio::frontend::Frontend;
use doppio::LedgerFrontend;

let fe = LedgerFrontend;
assert!(fe.extensions().contains(&"ledger"));

Required Methods§

Source

fn extensions(&self) -> &'static [&'static str]

File extensions this frontend recognises (lowercase, without the dot).

The CLI calls this for each registered frontend and selects the first one whose extension list contains the source file’s extension.

Source

fn elaboration_defaults(&self) -> ElaborationConfig

The default elaboration semantics for files in this frontend’s syntax — i.e. the ElaborationConfig that mirrors what the canonical tool’s own elaborator would do.

This is a convenience pairing, not a forced coupling. The elaborator takes any ElaborationConfig; a caller can parse a file in one frontend’s syntax and elaborate it under a different tool’s rules. The associated default is what dop-style command dispatchers use when the user hasn’t asked for anything more specific.

Source

fn parse( &self, input: &str, base_path: &Path, opener: &Opener, ) -> Result<HIR, Box<dyn Error>>

Parse source text into an HIR.

§Parameters

input – the complete source text of the file being parsed.
base_path – the directory of the file currently being parsed. Used to resolve relative paths in include directives.
opener – invoked for each include directive with the resolved path (or glob pattern). Must return the concatenated file contents or an error. Pass |_| Ok(String::new()) to silently ignore includes.