####### DOCUMENTATIATOIAITAT ION ########


a simple c-like language with support for if/else-statements, while-loops and the standard arithmetic (+, -, /, *) and comparison expressions (<, >, <=, >=, ==, !=). also, post increase/decrease expressions (++, --) are supported. Assignments are allowed in expressions, but they are only allowed on the right side of arithmetic/comparision operators if they are put inside parenthesis


data types:
integers and booleans.

comments:
// and /* */ comments are allowed.

(For compilation to work the Bool type in Abssyntax has to be removed so the internal haskell type is used)

shift/reduce conflicts:

if with else: 1 conflict
An if statement before the else could be reduced to an if statement lacking the else, but the correct thing is to shift it onto the stack.




typing rules
++++++++++++


(t is little tau, T is large tau, E is 'in', and + is that other symbol)



[Eq, Neq]

e:bool  <=  e1:t  &  e2:t
where e is e1 Eq e2.


[Plus, Minus, Times, Div]

e:int  <=  e1:int  &  e2:int
where e is e1 Plus e2.


[Lt, ELt, Gt, EGt]

e:bool  <=  e1:int  &  e2:int
where e is e1 Lt e2.


[Assignment]

T+ i := e:t  <=  i:t E T  &  T+ e:t
where the assignment is identifier i = expression e.


[ExpT]

u,e:t  <=  e:t  &  u:t
where the expression is type u expression e.


[ENeg]

e:int  <=  e:int


[ENot]

e:bool  <=  e:bool


[SExp, SBlock]

S:NoType  <=  e:t


[SIf]

T+ if e then s1 else s2  <=  T+ e:bool  &  T+ s1  &  T+ s2


[SWhile]

T+ while e do s  <=  T+ e:bool  &  T+ s


[SDecl]

T+ i:t => T', i:t  <=  i!ET  &  e:t  &  u:t

(Type u Ident i = Exp e)