library/core/src/fmt/rt/v1.rs

   1 //! This is an internal module used by the ifmt! runtime. These structures are
   2 //! emitted to static arrays to precompile format strings ahead of time.
   3 //!
   4 //! These definitions are similar to their `ct` equivalents, but differ in that
   5 //! these can be statically allocated and are slightly optimized for the runtime
   6 #![allow(missing_debug_implementations)]
   7
   8 #[lang = "format_placeholder"]
   9 #[derive(Copy, Clone)]
  10 // FIXME: Rename this to Placeholder
  11 pub struct Argument {
  12     pub position: usize,
  13     pub format: FormatSpec,
  14 }
  15
  16 #[derive(Copy, Clone)]
  17 pub struct FormatSpec {
  18     pub fill: char,
  19     pub align: Alignment,
  20     pub flags: u32,
  21     pub precision: Count,
  22     pub width: Count,
  23 }
  24
  25 impl Argument {
  26     #[inline(always)]
  27     pub const fn new(
  28         position: usize,
  29         fill: char,
  30         align: Alignment,
  31         flags: u32,
  32         precision: Count,
  33         width: Count,
  34     ) -> Self {
  35         Self { position, format: FormatSpec { fill, align, flags, precision, width } }
  36     }
  37 }
  38
  39 /// Possible alignments that can be requested as part of a formatting directive.
  40 #[lang = "format_alignment"]
  41 #[derive(Copy, Clone, PartialEq, Eq)]
  42 pub enum Alignment {
  43     /// Indication that contents should be left-aligned.
  44     Left,
  45     /// Indication that contents should be right-aligned.
  46     Right,
  47     /// Indication that contents should be center-aligned.
  48     Center,
  49     /// No alignment was requested.
  50     Unknown,
  51 }
  52
  53 /// Used by [width](https://doc.rust-lang.org/std/fmt/#width) and [precision](https://doc.rust-lang.org/std/fmt/#precision) specifiers.
  54 #[lang = "format_count"]
  55 #[derive(Copy, Clone)]
  56 pub enum Count {
  57     /// Specified with a literal number, stores the value
  58     Is(usize),
  59     /// Specified using `$` and `*` syntaxes, stores the index into `args`
  60     Param(usize),
  61     /// Not specified
  62     Implied,
  63 }