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use crate::ptr::P;
use crate::Expr;
use rustc_data_structures::fx::FxHashMap;
use rustc_span::symbol::{Ident, Symbol};
use rustc_span::Span;
// Definitions:
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └──────────────────────────────────────────────┘
// FormatArgs
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └─────────┘
// argument
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └───────────────────┘
// template
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └────┘└─────────┘└┘
// pieces
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └────┘ └┘
// literal pieces
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └─────────┘
// placeholder
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └─┘ └─┘
// positions (could be names, numbers, empty, or `*`)
/// (Parsed) format args.
///
/// Basically the "AST" for a complete `format_args!()`.
///
/// E.g., `format_args!("hello {name}");`.
#[derive(Clone, Encodable, Decodable, Debug)]
pub struct FormatArgs {
pub span: Span,
pub template: Vec<FormatArgsPiece>,
pub arguments: FormatArguments,
}
/// A piece of a format template string.
///
/// E.g. "hello" or "{name}".
#[derive(Clone, Encodable, Decodable, Debug)]
pub enum FormatArgsPiece {
Literal(Symbol),
Placeholder(FormatPlaceholder),
}
/// The arguments to format_args!().
///
/// E.g. `1, 2, name="ferris", n=3`,
/// but also implicit captured arguments like `x` in `format_args!("{x}")`.
#[derive(Clone, Encodable, Decodable, Debug)]
pub struct FormatArguments {
arguments: Vec<FormatArgument>,
num_unnamed_args: usize,
num_explicit_args: usize,
names: FxHashMap<Symbol, usize>,
}
impl FormatArguments {
pub fn new() -> Self {
Self {
arguments: Vec::new(),
names: FxHashMap::default(),
num_unnamed_args: 0,
num_explicit_args: 0,
}
}
pub fn add(&mut self, arg: FormatArgument) -> usize {
let index = self.arguments.len();
if let Some(name) = arg.kind.ident() {
self.names.insert(name.name, index);
} else if self.names.is_empty() {
// Only count the unnamed args before the first named arg.
// (Any later ones are errors.)
self.num_unnamed_args += 1;
}
if !matches!(arg.kind, FormatArgumentKind::Captured(..)) {
// This is an explicit argument.
// Make sure that all arguments so far are explicit.
assert_eq!(
self.num_explicit_args,
self.arguments.len(),
"captured arguments must be added last"
);
self.num_explicit_args += 1;
}
self.arguments.push(arg);
index
}
pub fn by_name(&self, name: Symbol) -> Option<(usize, &FormatArgument)> {
let i = *self.names.get(&name)?;
Some((i, &self.arguments[i]))
}
pub fn by_index(&self, i: usize) -> Option<&FormatArgument> {
(i < self.num_explicit_args).then(|| &self.arguments[i])
}
pub fn unnamed_args(&self) -> &[FormatArgument] {
&self.arguments[..self.num_unnamed_args]
}
pub fn named_args(&self) -> &[FormatArgument] {
&self.arguments[self.num_unnamed_args..self.num_explicit_args]
}
pub fn explicit_args(&self) -> &[FormatArgument] {
&self.arguments[..self.num_explicit_args]
}
pub fn all_args(&self) -> &[FormatArgument] {
&self.arguments[..]
}
pub fn all_args_mut(&mut self) -> &mut Vec<FormatArgument> {
&mut self.arguments
}
}
#[derive(Clone, Encodable, Decodable, Debug)]
pub struct FormatArgument {
pub kind: FormatArgumentKind,
pub expr: P<Expr>,
}
#[derive(Clone, Encodable, Decodable, Debug)]
pub enum FormatArgumentKind {
/// `format_args(…, arg)`
Normal,
/// `format_args(…, arg = 1)`
Named(Ident),
/// `format_args("… {arg} …")`
Captured(Ident),
}
impl FormatArgumentKind {
pub fn ident(&self) -> Option<Ident> {
match self {
&Self::Normal => None,
&Self::Named(id) => Some(id),
&Self::Captured(id) => Some(id),
}
}
}
#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub struct FormatPlaceholder {
/// Index into [`FormatArgs::arguments`].
pub argument: FormatArgPosition,
/// The span inside the format string for the full `{…}` placeholder.
pub span: Option<Span>,
/// `{}`, `{:?}`, or `{:x}`, etc.
pub format_trait: FormatTrait,
/// `{}` or `{:.5}` or `{:-^20}`, etc.
pub format_options: FormatOptions,
}
#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub struct FormatArgPosition {
/// Which argument this position refers to (Ok),
/// or would've referred to if it existed (Err).
pub index: Result<usize, usize>,
/// What kind of position this is. See [`FormatArgPositionKind`].
pub kind: FormatArgPositionKind,
/// The span of the name or number.
pub span: Option<Span>,
}
#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub enum FormatArgPositionKind {
/// `{}` or `{:.*}`
Implicit,
/// `{1}` or `{:1$}` or `{:.1$}`
Number,
/// `{a}` or `{:a$}` or `{:.a$}`
Named,
}
#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq, Hash)]
pub enum FormatTrait {
/// `{}`
Display,
/// `{:?}`
Debug,
/// `{:e}`
LowerExp,
/// `{:E}`
UpperExp,
/// `{:o}`
Octal,
/// `{:p}`
Pointer,
/// `{:b}`
Binary,
/// `{:x}`
LowerHex,
/// `{:X}`
UpperHex,
}
#[derive(Clone, Encodable, Decodable, Default, Debug, PartialEq, Eq)]
pub struct FormatOptions {
/// The width. E.g. `{:5}` or `{:width$}`.
pub width: Option<FormatCount>,
/// The precision. E.g. `{:.5}` or `{:.precision$}`.
pub precision: Option<FormatCount>,
/// The alignment. E.g. `{:>}` or `{:<}` or `{:^}`.
pub alignment: Option<FormatAlignment>,
/// The fill character. E.g. the `.` in `{:.>10}`.
pub fill: Option<char>,
/// The `+` or `-` flag.
pub sign: Option<FormatSign>,
/// The `#` flag.
pub alternate: bool,
/// The `0` flag. E.g. the `0` in `{:02x}`.
pub zero_pad: bool,
/// The `x` or `X` flag (for `Debug` only). E.g. the `x` in `{:x?}`.
pub debug_hex: Option<FormatDebugHex>,
}
#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub enum FormatSign {
/// The `+` flag.
Plus,
/// The `-` flag.
Minus,
}
#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub enum FormatDebugHex {
/// The `x` flag in `{:x?}`.
Lower,
/// The `X` flag in `{:X?}`.
Upper,
}
#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub enum FormatAlignment {
/// `{:<}`
Left,
/// `{:>}`
Right,
/// `{:^}`
Center,
}
#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
pub enum FormatCount {
/// `{:5}` or `{:.5}`
Literal(usize),
/// `{:.*}`, `{:.5$}`, or `{:a$}`, etc.
Argument(FormatArgPosition),
}