Trait Language 

pub trait Language:
    Clone
    + Debug
    + Send
    + Sync
    + 'static {
    // Required methods
    fn kind_to_id(&self, kind: &str) -> u16;
    fn field_to_id(&self, field: &str) -> Option<u16>;
    fn build_pattern(
        &self,
        builder: &PatternBuilder<'_>,
    ) -> Result<Pattern, PatternError>;

    // Provided methods
    fn pre_process_pattern<'q>(&self, query: &'q str) -> Cow<'q, str> { ... }
    fn meta_var_char(&self) -> char { ... }
    fn expando_char(&self) -> char { ... }
    fn extract_meta_var(&self, source: &str) -> Option<MetaVariable> { ... }
    fn from_path<P>(_path: P) -> Option<Self>
       where P: AsRef<Path> { ... }
}

Trait to abstract ts-language usage in ast-grep, which includes:

• which character is used for meta variable.
• if we need to use other char in meta var for parser at runtime
• pre process the Pattern code.

Required Methods

fn kind_to_id(&self, kind: &str) -> u16

fn field_to_id(&self, field: &str) -> Option<u16>

fn build_pattern( &self, builder: &PatternBuilder<'_>, ) -> Result<Pattern, PatternError>

Provided Methods

fn pre_process_pattern<'q>(&self, query: &'q str) -> Cow<'q, str>

normalize pattern code before matching e.g. remove expression_statement, or prefer parsing {} to object over block

fn meta_var_char(&self) -> char

Configure meta variable special character By default $ is the metavar char, but in PHP it can be #

fn expando_char(&self) -> char

Some language does not accept $ as the leading char for identifiers. We need to change $ to other char at run-time to make parser happy, thus the name expando. By default this is the same as meta_var char so replacement is done at runtime.

fn extract_meta_var(&self, source: &str) -> Option<MetaVariable>

extract MetaVariable from a given source string At runtime we need to use expand_char

fn from_path<P>(_path: P) -> Option<Self>

where P: AsRef<Path>,

Return the file language from path. Return None if the file type is not supported.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Language for Bash

impl Language for C

impl Language for CSharp

impl Language for Cpp

impl Language for Css

impl Language for Elixir

impl Language for Go

impl Language for Haskell

impl Language for Hcl

impl Language for Html

impl Language for Java

impl Language for JavaScript

impl Language for Json

impl Language for Kotlin

impl Language for Lua

impl Language for Nix

impl Language for Php

impl Language for Python

impl Language for Ruby

impl Language for Rust

impl Language for Scala

impl Language for Solidity

impl Language for SupportLang

Available on crate feature matching and (crate features all-parsers or bash or c or cpp or csharp or css or elixir or go or haskell or hcl or html or java or javascript or json or kotlin or lua or napi-compatible or napi-environment or nix or php or python or ruby or rust or scala or solidity or swift or tsx or typescript or yaml) only.

impl Language for Swift

impl Language for Tsx

impl Language for TypeScript

impl Language for Yaml