Grammar Pocket Reference

Checksum: 4ab4e767d61092f8b4f0c031e617d8ddaccf9515fbf6ba702a107b2bca58b7f2

• program ::= WS? { toplevel WS? } EOF ;
• toplevel ::= inner_attribute
• space_decl ::= "space" WS1 module_path ;
• use_decl ::= "use" WS1 package_path [ use_group | use_glob ] [ WS1 "as" WS1 ident ] ;
• use_glob ::= "." "*" ;
• use_group ::= "." "{" WS? ( "*" | import_items [ WS? "," WS? "*" ]? ) WS? "}" ;
• import_items ::= import_item { WS? "," WS? import_item } [ WS? "," ] ;
• import_item ::= ident [ WS1 "as" WS1 ident ] ;
• export_decl ::= "export" WS1 ( "*" | ident_list | "{" WS? ident_list WS? "}" ) ;
• const_decl ::= { attr_prefix WS? } "const" WS1 ident [ WS? ":" WS? type_expr ] WS? "=" WS? expr ;
• static_decl ::= { attr_prefix WS? } "static" WS1 ident [ WS? ":" WS? type_expr ] WS? "=" WS? expr ;
• region_decl ::= { attr_prefix WS? } "region" WS1 ident [ WS? ":" WS? region_kind ] [ WS? region_capabilities ] WS? meta_tail ;
• region_kind ::= "stack" | "heap" | "arena" | "static" | "mmio" | "dma" | ident ;
• region_capabilities ::= "(" WS? ident_list? WS? ")" ;
• type_alias_decl ::= { attr_prefix WS? } "type" WS1 ident [ generic_params ] WS? "=" WS? type_expr ;
• opaque_type_decl ::= { attr_prefix WS? } "opaque" WS1 "type" WS1 ident [ generic_params ] [ WS? "=" WS? type_expr ] ;
• extern_type_decl ::= { attr_prefix WS? } "extern" WS1 "type" WS1 ident [ generic_params ] [ WS? ";" ] ;
• form_decl ::= { attr_prefix WS? } "form" WS1 ident [ generic_params ] [ WS? where_clause ] WS? "{" WS? form_items? WS? "}" ;
• class_decl ::= { attr_prefix WS? } "class" WS1 ident [ generic_params ] [ WS? where_clause ] WS? "{" WS? class_items? WS? "}" ;
• union_decl ::= { attr_prefix WS? } "union" WS1 ident [ generic_params ] [ WS? where_clause ] WS? "{" WS? field_list? WS? "}" ;
• form_items ::= form_item { WS? ","? WS? form_item } [ WS? "," ] ;
• form_item ::= field_item | const_decl | type_alias_decl | proc_decl ;
• class_items ::= class_item { WS? ","? WS? class_item } [ WS? "," ] ;
• class_item ::= field_item | const_decl | type_alias_decl | proc_decl ;
• field_list ::= field_item { WS? "," WS? field_item } [ WS? "," ] ;
• field_item ::= { attr_prefix WS? } [ visibility WS1 ] ident WS? ":" WS? type_expr [ WS? "=" WS? expr ] ;
• bits_decl ::= { attr_prefix WS? } "bits" WS1 ident [ WS? ":" WS? type_expr ] WS? "{" WS? bitfield_list? WS? "}" ;
• bitfield_list ::= bitfield_item { WS? "," WS? bitfield_item } [ WS? "," ] ;
• bitfield_item ::= ident WS? ":" WS? expr WS? ".." WS? expr ;
• pick_decl ::= { attr_prefix WS? } "pick" WS1 ident [ generic_params ] [ WS? ":" WS? type_expr ] [ WS? where_clause ] WS? "{" WS? case_list? WS? "}" ;
• case_list ::= case_item { WS? "," WS? case_item } [ WS? "," ] ;
• case_item ::= [ "case" WS1 ] ident [ "(" WS? case_payload? WS? ")" ] [ WS? "=" WS? expr ] ;
• case_payload ::= case_field { WS? "," WS? case_field } [ WS? "," ] ;
• case_field ::= ident WS? ":" WS? type_expr | type_expr ;
• flags_decl ::= { attr_prefix WS? } "flags" WS1 ident [ WS? ":" WS? type_expr ] WS? "{" WS? flag_list? WS? "}" ;
• flag_list ::= flag_item { WS? "," WS? flag_item } [ WS? "," ] ;
• flag_item ::= ident [ WS? "=" WS? expr ] ;
• trait_decl ::= { attr_prefix WS? } [ "unsafe" WS1 ] "trait" WS1 ident [ generic_params ] [ WS? where_clause ] WS? "{" WS? trait_item* WS? "}" ;
• trait_item ::= proc_signature | const_decl | associated_type_decl ;
• associated_type_decl ::= "type" WS1 ident [ WS? ":" WS? trait_bound ] [ WS? "=" WS? type_expr ] ;
• impl_decl ::= { attr_prefix WS? } [ "unsafe" WS1 ] "impl" WS1 impl_head [ WS? where_clause ] WS? "{" WS? impl_item* WS? "}" ;
• impl_head ::= type_expr | type_expr WS1 "for" WS1 type_expr ;
• impl_item ::= const_decl | type_alias_decl | associated_type_decl | proc_decl ;
• proc_signature ::= { attr_prefix WS? } "proc" WS1 ident [ generic_params ]
• proc_decl ::= { attr_prefix WS? } [ visibility WS1 ] proc_modifier* [ extern_clause WS1 ] "proc" WS1 proc_name [ generic_params ]
• proc_name ::= ident | "operator" WS? operator_symbol ;
• operator_symbol ::= "+" | "-" | "*" | "/" | "%"
• proc_modifier ::= "async" WS1
• proc_suffix ::= effects_clause
• extern_block ::= { attr_prefix WS? } "extern" WS1 extern_abi WS? "{" WS? extern_item* WS? "}" ;
• extern_item ::= extern_proc_decl | extern_type_decl | const_decl ;
• extern_proc_decl ::= { attr_prefix WS? } "proc" WS1 ident [ generic_params ]
• extern_clause ::= "extern" WS1 extern_abi ;
• extern_abi ::= callconv | string_lit ;
• callconv ::= "C" | "sysv64" | "win64" | "interrupt" | "naked" ;
• intrinsic_decl ::= { attr_prefix WS? } "intrinsic" WS1 ident [ generic_params ]
• macro_decl ::= { attr_prefix WS? } "macro" WS1 ident [ "(" WS? macro_param_list? WS? ")" ] WS? meta_tail ;
• macro_param_list ::= macro_param { WS? "," WS? macro_param } [ WS? "," ] ;
• macro_param ::= ident [ WS? ":" WS? macro_kind ] ;
• macro_kind ::= "expr" | "stmt" | "type" | "ident" | "block" | "item" ;
• static_assert_decl ::= "static_assert" WS? "(" WS? expr [ WS? "," WS? expr ] WS? ")" ;
• test_decl ::= { attr_prefix WS? } "test" WS1 string_lit WS? block ;
• bench_decl ::= { attr_prefix WS? } "bench" WS1 string_lit WS? block ;
• entry_decl ::= { attr_prefix WS? } "entry" WS1 ident_or_string [ WS? meta_args ] WS? meta_tail ;
• visibility ::= "pub" | "priv" | "pub" WS? "(" WS? visibility_scope WS? ")" ;
• visibility_scope ::= "package" | "module" | "super" ;
• generic_params ::= "[" WS? generic_param_list? WS? "]" ;
• generic_param_list ::= generic_param { WS? "," WS? generic_param } [ WS? "," ] ;
• generic_param ::= ident [ WS? ":" WS? trait_bound ] [ WS? "=" WS? type_expr ]
• where_clause ::= "where" WS1 where_bounds ;
• where_bounds ::= where_bound { WS? "," WS? where_bound } [ WS? "," ] ;
• where_bound ::= type_expr WS? ":" WS? trait_bound
• trait_bound ::= type_expr { WS? "+" WS? type_expr } ;
• param_list ::= param { WS? "," WS? param } [ WS? "," ] ;
• param ::= self_param | normal_param | variadic_param ;
• self_param ::= [ "&" WS? ] [ "mut" WS1 ] "self" ;
• normal_param ::= [ param_mode WS1 ] pattern [ WS? ":" WS? type_expr ] [ WS? "=" WS? expr ] ;
• variadic_param ::= "..." | ident WS? ":" WS? "..." type_expr ;
• param_mode ::= "mut" | "owned" | "borrow" | "move" ;
• effects_clause ::= "effects" WS? "(" WS? ident_list? WS? ")" ;
• requires_clause ::= "requires" WS? "(" WS? capability_list? WS? ")" ;
• capability_list ::= capability { WS? "," WS? capability } [ WS? "," ] ;
• capability ::= ident { "." ident } ;
• module_path ::= relative? package_parts ;
• package_path ::= relative? package_parts ;
• relative ::= { "." } ;
• package_parts ::= ident { ( "/" | "." | "::" ) ident } ;
• ident_list ::= ident { WS? "," WS? ident } [ WS? "," ] ;
• query_decl ::= { attr_prefix WS? } "query" WS1 ident
• query_body ::= block | ";" ;
• compiler_decl ::= { attr_prefix WS? } "compiler" WS1 ident_or_string [ WS? meta_args ] WS? meta_tail ;
• pass_decl ::= { attr_prefix WS? } "pass" WS1 ident_or_string [ WS? meta_args ] WS? meta_tail ;
• backend_decl ::= { attr_prefix WS? } "backend" WS1 ident_or_string [ WS? meta_args ] WS? meta_tail ;
• diagnostic_decl ::= { attr_prefix WS? } "diagnostic" WS1 ident_or_string [ WS? meta_args ] WS? meta_tail ;
• ident_or_string ::= ident | string_lit ;
• meta_args ::= "(" WS? meta_arg_list? WS? ")" ;
• meta_arg_list ::= meta_arg { WS? "," WS? meta_arg } [ WS? "," ] ;
• meta_arg ::= ident_or_string ;
• meta_tail ::= block | ";" ;
• attr_prefix ::= outer_attribute | doc_comment | docstring ;
• inner_attribute ::= "#![" attr_path [ "(" WS? attr_arg_list? WS? ")" ] "]" ;
• outer_attribute ::= "#[" attr_path [ "(" WS? attr_arg_list? WS? ")" ] "]" ;
• doc_comment ::= "///" { ~NEWLINE ANY } ;
• docstring ::= raw_string_lit ;
• attr_path ::= ident { "." ident } ;
• attr_arg_list ::= attr_arg { WS? "," WS? attr_arg } [ WS? "," ] ;
• attr_arg ::= ident
• block ::= "{" WS? { stmt WS? } "}" ;
• stmt ::= local_const_stmt stmt_end
• stmt_end ::= WS? ";" ;
• local_const_stmt ::= "const" WS1 ident [ WS? ":" WS? type_expr ] WS? "=" WS? expr ;
• let_stmt ::= "let" WS1 [ "mut" WS1 ] pattern [ WS? ":" WS? type_expr ] WS? "=" WS? expr ;
• set_stmt ::= "set" WS1 assign_target WS? assign_op WS? expr ;
• assign_target ::= unary_expr ;
• give_stmt ::= "give" [ WS1 expr ] ;
• try_stmt ::= "try" WS1 expr ;
• defer_stmt ::= "defer" WS? block ;
• asm_stmt ::= "asm" WS? "(" WS? asm_arg_list? WS? ")" ;
• asm_arg_list ::= asm_arg { WS? "," WS? asm_arg } [ WS? "," ] ;
• asm_arg ::= string_lit | ident WS? "(" WS? arg_list? WS? ")" | ident WS? ":" WS? expr ;