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mirror of https://github.com/sharkdp/bat synced 2024-11-08 19:10:41 +00:00
bat/build/syntax_mapping.rs
2023-12-11 10:20:10 +08:00

110 lines
3.4 KiB
Rust

use std::{convert::Infallible, env, fs, path::Path, str::FromStr};
use anyhow::anyhow;
use indexmap::IndexMap;
use serde::Deserialize;
use serde_with::DeserializeFromStr;
use walkdir::WalkDir;
/// Known mapping targets.
///
/// Corresponds to `syntax_mapping::MappingTarget`.
#[derive(Clone, Debug, Eq, PartialEq, Hash, DeserializeFromStr)]
pub enum MappingTarget {
MapTo(String),
MapToUnknown,
MapExtensionToUnknown,
}
impl FromStr for MappingTarget {
type Err = Infallible;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"MappingTarget::MapToUnknown" => Ok(Self::MapToUnknown),
"MappingTarget::MapExtensionToUnknown" => Ok(Self::MapExtensionToUnknown),
syntax => Ok(Self::MapTo(syntax.into())),
}
}
}
impl MappingTarget {
fn codegen(&self) -> String {
match self {
Self::MapTo(syntax) => format!(r###"MappingTarget::MapTo(r#"{syntax}"#)"###),
Self::MapToUnknown => "MappingTarget::MapToUnknown".into(),
Self::MapExtensionToUnknown => "MappingTarget::MapExtensionToUnknown".into(),
}
}
}
/// A struct that models a single .toml file in /src/syntax_mapping/builtins/.
#[derive(Clone, Debug, Deserialize)]
struct MappingDefModel {
mappings: IndexMap<MappingTarget, Vec<String>>,
}
impl MappingDefModel {
fn into_mapping_list(self) -> MappingList {
let list = self
.mappings
.into_iter()
.flat_map(|(target, matcher)| {
matcher
.into_iter()
.map(|rule| (rule, target.clone()))
.collect::<Vec<_>>()
})
.collect();
MappingList(list)
}
}
#[derive(Clone, Debug)]
struct MappingList(Vec<(String, MappingTarget)>);
impl MappingList {
fn codegen(&self) -> String {
let array_items: Vec<_> = self
.0
.iter()
.map(|(matcher, target)| format!(r###"(r#"{matcher}"#, {t})"###, t = target.codegen()))
.collect();
let len = array_items.len();
format!(
"static STATIC_RULES: [(&'static str, &'static str); {len}] = [\n{items}\n];",
items = array_items.join(",\n")
)
}
}
fn read_all_mappings() -> anyhow::Result<MappingList> {
let mut all_mappings = vec![];
for entry in WalkDir::new("src/syntax_mapping/builtins")
.sort_by_file_name()
.into_iter()
.map(|entry| entry.unwrap_or_else(|err| panic!("failed to visit a file: {err}")))
.filter(|entry| {
let path = entry.path();
path.is_file() && path.extension().map(|ext| ext == "toml").unwrap_or(false)
})
{
let toml_string = fs::read_to_string(entry.path())?;
let mappings = toml::from_str::<MappingDefModel>(&toml_string)?.into_mapping_list();
all_mappings.extend(mappings.0);
}
Ok(MappingList(all_mappings))
}
/// Build the static syntax mappings defined in /src/syntax_mapping/builtins/
/// into a .rs source file, which is to be inserted with `include!`.
pub fn build_static_mappings() -> anyhow::Result<()> {
let mappings = read_all_mappings()?;
let codegen_path = Path::new(&env::var_os("OUT_DIR").ok_or(anyhow!("OUT_DIR is unset"))?)
.join("codegen_static_syntax_mappings.rs");
fs::write(codegen_path, mappings.codegen())?;
Ok(())
}