src/doc/reference/src/notation.md

   1 # Notation
   2
   3 ## Unicode productions
   4
   5 A few productions in Rust's grammar permit Unicode code points outside the
   6 ASCII range. We define these productions in terms of character properties
   7 specified in the Unicode standard, rather than in terms of ASCII-range code
   8 points. The grammar has a [Special Unicode Productions] section that lists these
   9 productions.
  10
  11 ## String table productions
  12
  13 Some rules in the grammar &mdash; notably [unary operators], [binary operators],
  14 and [keywords] &mdash; are given in a simplified form: as a listing of a table
  15 of unquoted, printable whitespace-separated strings. These cases form a subset
  16 of the rules regarding the [token][tokens] rule, and are assumed to be the
  17 result of a lexical-analysis phase feeding the parser, driven by a
  18 <abbr title="Deterministic Finite Automaton">DFA</abbr>, operating over the
  19 disjunction of all such string table entries.
  20
  21 When such a string enclosed in double-quotes (`"`) occurs inside the grammar,
  22 it is an implicit reference to a single member of such a string table
  23 production. See [tokens] for more information.
  24
  25 [Special Unicode Productions]: ../grammar.html#special-unicode-productions
  26 [binary operators]: expressions/operator-expr.html#arithmetic-and-logical-binary-operators
  27 [keywords]: keywords.html
  28 [tokens]: tokens.html
  29 [unary operators]: expressions/operator-expr.html#borrow-operators