====== Built-in BNF items for pgen ======

The built-in BNF items for [[tools:pgen:|''pgen'']] are:
   * ''INT'': integers
   * ''REAL'': real numbers
   * ''ID'': C-style identifiers
   * ''STRING'': strings
   * ''expr'': C-style expressions of any type
   * ''int_expr'': integer expressions
   * ''bool_expr'': Boolean expressions

If any of the expression constructs are used, then the user must also define the BNF item ''expr_id'', which is used to parse the identifiers that can be part of an expression.

^ Type          ^ Value     ^
| ''INT''       | ''int''   |
| ''REAL''      | ''double''|
| ''ID''        | ''char *''|
| ''STRING''    | ''char *''|
| ''expr''      | ''Expr *''|
| ''int_expr''  | ''Expr *''|
| ''bool_expr'' | ''Expr *''|

The ''char *'' returned for a ''STRING'' includes the two double-quotes that delimit the string.