Here is the beginnings of a BNF for ParaSail. It is incomplete, particularly in the lower level productions for compound statements. Also there is no attempt to convey precedence of operators. The intent is that "normal" precedence would be used for the familiar arithmetic operators, and for less familiar operators, parenthesization would be required to disambiguate if there might be any confusion possible. Future postings will elaborate on these productions with examples, etc. We may also edit this posting to add some of the missing lower-level productions.
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module ::= interface_declaration | class_definition
interface_declaration ::=
[abstract] [concurrent] interface module_defining_name
[ extends interface_name_list ]
'<' module_formal_list '>' is
interface_element_list
end interface module_defining_name;
module_defining_name ::= identifier { '::' identifier }
module_formal_list ::=
[ annotated_module_formal { ';' annotated_module_formal } ]
annotated_module_formal ::=
[ annotation ] module_formal [ annotation ]
module_formal ::= type_formal | value_formal
type_formal ::= [identifier is] module_instantiation
value_formal ::= identifier ':' type_name
type_name ::= qualified_name
qualified_name ::= identifier { '::' identifier }
module_instantiation ::=
module_name '<' module_actual_list '>'
module_name ::= qualified_name
module_actual_list ::= [ module_actual { ',' module_actual } ]
module_actual ::=
[ selector '=>' ] type_specifier
| [ selector '=>' ] expression
selector ::= identifier
type_specifier ::=
type_name [ annotation ] | module_instantiation
interface_element_list ::= { interface_element ';' }
interface_element ::=
operation_declaration | object_declaration
| interface_declaration | type_declaration
class_definition ::=
[concurrent] class module_defining_name
[ extends interface_name ]
'<' module_formal_list '>' is
{ local_class_element ';' }
exports
{ exported_class_element ';' }
end class module_defining_name;
local_class_element ::=
interface_element | exported_class_element
exported_class_element ::=
operation_definition | object_definition | class_definition
annotation ::= '{' annotation_element_list '}'
annotation_element_list ::=
annotation_element { ';' annotation_element }
annotation_element ::= boolean_expression
boolean_expression ::= expression
operation_declaration ::=
function_declaration | procedure_declaration | operator_declaration
function_declaration ::=
function identifier [ operation_input_list ] '->' operation_output_list
procedure declaration ::=
procedure identifier operation_input_list
operator_declaration ::=
operator operator_designator operation_input_list
[ '->' operation_output_list ]
operator_designator ::= string_literal
operation_input_list ::=
annotated_operation_input
| '(' annotated_operation_input { ';' annotated_operation_input } ')'
[ annotation ]
annotated_operation_input ::=
[ annotation ] operation_input [ annotation ]
operation_input ::=
[ identifier ':' ] [ input_modifier ] operand_type_specifier
operand_type_specifier ::= type_name | type_formal
input_modifier ::= output_modifier
| queued [ output_modifier ]
| locked [ output_modifier ]
operation_output_list ::=
annotated_operation_output
| '(' annotated_operation_output { ';' annotated_operation_output } ')'
[ annotation ]
annotated_operation_output ::=
[ annotation ] operation_output [ annotation ]
operation_output ::=
[ identifier ':' ] [ output_modifier ] operand_type_specifier
output_modifier ::= ref | ref var | ref const
object_delaration ::=
var_or_const identifier ':' type_specifier [ ':=' expression ]
var_or_const ::= var | const
object_definition ::=
const identifier [ ':' type_specifier ] ':=' expression
| var identifier ':' [ optional ] type_specifier [ ':=' expression ]
| var identifier ':=' expression
type_declaration ::= type identifier is [ new ] type_specifier
operation_definition ::=
function_definition | procedure_definition | operator_definition
function_definition ::=
function_declaration is statement_list ';' end function identifier
procedure_definition ::=
procedure_declaration is statement_list ';' end procedure identifier
operator_definition ::=
operator_declaration is statement_list ';' end operator identifier
statement_list ::=
annotated_statement
| statement_list ';;' statement_list
| statement_list ';' statement_list
| statement_list '||' statement_list
| '(' statement_list ')'
annotated_statement ::= [ annotation ] statement [ annotation ]
statement ::= local_declaration | local_definition
| simple_statement | compound_statement
simple_statement ::=
variable ':=' expression
| variable ':=:' variable
| operation_name '(' operation_actual_list ')'
| return [ operation_actual_list ]
local_declaration ::= operation_declaration | type_declaration
local_definition ::=
object_definition
| operation_definition
compound_statement ::=
if_statement
| case_statement
| while_loop_statement
| for_loop_statement
expression ::=
primary
| aggregate
| operator expression
| expression operator expression
| operation_name '(' operation_actual_list ')'
| expression '[' operation_actual_list ']'
| expression '.' selector
| expression [not] in range
| expression '?' expression ':' expression
primary ::=
object_name
| integer_literal
| real_literal
| character_literal
| string_literal
| null
| '(' expression ')'
| '[[' expression ']]'
operation_actual_list ::= [ operation_actual { ',' operation_actual } ]
operation_actual ::= [ selector '=>' ] expression
operation_name ::= qualified_name
object_name ::= qualified_name
operator ::=
'+' | '-' | '*' | '/' | '**'
| '=?' | '=' | '!=' | '<' | '<=' | '>' | '>='
| and [then] | or [else] | xor | not | '==>'
aggregate ::= class_aggregate | container_aggregate
class_aggregate ::= '(' operation_actual_list ')'
container_aggregate ::= '[' container_element_list ']'
container_element_list ::= container_element { ',' container_element }
container_element ::= container_key '=>' expression_stream
container_key ::= expression
expression_stream ::= expression { '~' expression } [ ':' expression ]
comment ::= '//' { non_end_of_line_character }
string_literal ::= " { non_double_quote_character | escaped_character } "
character_literal ::= ' { non_single_quote_character | escaped_character } '
escaped_character ::= '\' { non_end_of_line_character }
