59 lines
1.3 KiB
Plaintext
59 lines
1.3 KiB
Plaintext
|
grammar Statement
|
||
|
|
include Expression
|
||
|
|
|
||
|
|
rule type
|
||
|
|
(typ:("int" | "ref") space*) { capture(:typ).to_s }
|
||
|
|
end
|
||
|
|
|
||
|
|
rule typed_arg
|
||
|
|
(type name_expression) {
|
||
|
|
Ast::TypedName.new(capture(:type).value , capture(:name_expression).value.name)
|
||
|
|
}
|
||
|
|
end
|
||
|
|
|
||
|
|
rule variable_definition
|
||
|
|
(typed_arg ("=" space* value_expression)?) {
|
||
|
|
type = capture(:typed_arg).value
|
||
|
|
value = capture(:value_expression) ? capture(:value_expression).value : nil
|
||
|
|
var = Ast::VariableDefinition.new(type.type , type.name , value)
|
||
|
|
}
|
||
|
|
end
|
||
|
|
|
||
|
|
rule assignment
|
||
|
|
(name_expression "=" space* value_expression){
|
||
|
|
Ast::AssignmentExpression.new( capture(:name_expression).value.name , capture(:value_expression).value)
|
||
|
|
}
|
||
|
|
end
|
||
|
|
|
||
|
|
rule conditional
|
||
|
|
(keyword_if left_parenthesis value_expression right_parenthesis
|
||
|
|
body
|
||
|
|
keyword_end) {
|
||
|
|
Ast::IfExpression.new( capture(:value_expression).value , capture(:body).value , nil)
|
||
|
|
}
|
||
|
|
end
|
||
|
|
|
||
|
|
rule while
|
||
|
|
keyword_while left_parenthesis value_expression right_parenthesis keyword_do
|
||
|
|
body
|
||
|
|
keyword_end
|
||
|
|
end
|
||
|
|
|
||
|
|
rule return
|
||
|
|
keyword_return value_expression newline
|
||
|
|
end
|
||
|
|
|
||
|
|
rule body
|
||
|
|
(statement+){
|
||
|
|
captures(:statement).collect{|u| u.value }
|
||
|
|
}
|
||
|
|
end
|
||
|
|
|
||
|
|
rule statement
|
||
|
|
conditional | while | return | variable_definition | assignment
|
||
|
|
end
|
||
|
|
|
||
|
|
root statement
|
||
|
|
|
||
|
|
end
|