Comprobación de Tipos

Especificación de la etapa de comprobación de tipos (perteneciente a la fase de análisis semántico) utilizando como metalenguaje una gramática atribuida:

Attributes

Symbol	Atribute Name	Java Type	Syn/Inh	Description
expression	type	Type	Synthetized	Type of the expression
expression	lvalue	boolean	Synthetized	True if the expression can appear to the left of an assignment

Auxiliary Functions

Name	Description
sameType(type_a, type_b)	True if the params are equal

Rules

Node	Predicates	Functions
program → varDefinition* statement*
varDefinition → type name:string
intType:type → ε
floatType:type → ε
print:statement → expression
assignment:statement → left:expression right:expression	sameType(left.type, right.type) left.lvalue == true
arithmetic:expression → left:expression operator:string right:expression	sameType(left.type, right.type)	arithmetic.type = left.type arithmetic.lvalue = false
variable:expression → name:string		variable.type = variable.varDefinition.type variable.lvalue = true
intLiteral:expression → intValue:int		intLiteral.type = intType intLiteral.lvalue = false
floatLiteral:expression → floatValue:float		floatLiteral.type = floatType floatLiteral.lvalue = false