Conlang/compiler/cl-ast/src/format.rs
John 82b71e2517 cl-typeck: Refactor display for Def.
- Use the FmtAdapter from cl-ast
  - Add a new delimiter-constructing delimit_with function.
2024-07-21 01:46:20 -05:00

83 lines
2.8 KiB
Rust

use delimiters::Delimiters;
use std::fmt::Write;
impl<W: Write + ?Sized> FmtAdapter for W {}
pub trait FmtAdapter: Write {
fn indent(&mut self) -> Indent<Self> {
Indent { f: self }
}
fn delimit(&mut self, delim: Delimiters) -> Delimit<Self> {
Delimit::new(self, delim)
}
fn delimit_with(&mut self, open: &'static str, close: &'static str) -> Delimit<Self> {
Delimit::new(self, Delimiters { open, close })
}
}
/// Pads text with leading indentation after every newline
pub struct Indent<'f, F: Write + ?Sized> {
f: &'f mut F,
}
impl<'f, F: Write + ?Sized> Write for Indent<'f, F> {
fn write_str(&mut self, s: &str) -> std::fmt::Result {
for s in s.split_inclusive('\n') {
self.f.write_str(s)?;
if s.ends_with('\n') {
self.f.write_str(" ")?;
}
}
Ok(())
}
}
/// Prints [Delimiters] around anything formatted with this. Implies [Indent]
pub struct Delimit<'f, F: Write + ?Sized> {
f: Indent<'f, F>,
delim: Delimiters,
}
impl<'f, F: Write + ?Sized> Delimit<'f, F> {
pub fn new(f: &'f mut F, delim: Delimiters) -> Self {
let mut f = f.indent();
let _ = f.write_str(delim.open);
Self { f, delim }
}
}
impl<'f, F: Write + ?Sized> Drop for Delimit<'f, F> {
fn drop(&mut self) {
let Self { f: Indent { f, .. }, delim } = self;
let _ = f.write_str(delim.close);
}
}
impl<'f, F: Write + ?Sized> Write for Delimit<'f, F> {
fn write_str(&mut self, s: &str) -> std::fmt::Result {
self.f.write_str(s)
}
}
pub mod delimiters {
#![allow(dead_code)]
#[derive(Clone, Copy, Debug)]
pub struct Delimiters {
pub open: &'static str,
pub close: &'static str,
}
/// Delimits with braces decorated with spaces `" {\n"`, ..., `"\n}"`
pub const SPACED_BRACES: Delimiters = Delimiters { open: " {\n", close: "\n}" };
/// Delimits with braces on separate lines `{\n`, ..., `\n}`
pub const BRACES: Delimiters = Delimiters { open: "{\n", close: "\n}" };
/// Delimits with parentheses on separate lines `{\n`, ..., `\n}`
pub const PARENS: Delimiters = Delimiters { open: "(\n", close: "\n)" };
/// Delimits with square brackets on separate lines `{\n`, ..., `\n}`
pub const SQUARE: Delimiters = Delimiters { open: "[\n", close: "\n]" };
/// Delimits with braces on the same line `{ `, ..., ` }`
pub const INLINE_BRACES: Delimiters = Delimiters { open: "{ ", close: " }" };
/// Delimits with parentheses on the same line `( `, ..., ` )`
pub const INLINE_PARENS: Delimiters = Delimiters { open: "(", close: ")" };
/// Delimits with square brackets on the same line `[ `, ..., ` ]`
pub const INLINE_SQUARE: Delimiters = Delimiters { open: "[", close: "]" };
}