X-Git-Url: https://ruin.nu/git/?a=blobdiff_plain;f=documentation;h=70bd0c818b7f8c298ca3658a67729c6413db122b;hb=ef4659dbfa5051372cf067f8c0ed2bbe77146650;hp=cb693df417c88f4430589c5ac0de2ce533360c91;hpb=67721d82f79e56db9c728aed76a3ad9dcca005c2;p=proglang.git diff --git a/documentation b/documentation index cb693df..70bd0c8 100644 --- a/documentation +++ b/documentation @@ -1,77 +1,97 @@ ####### 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 -a simple c-like language with support for if/else-statements, while-loops and the standard arithmetic (+, -, /, *) and comparison expressions (<, >, <=, >=, ==, !=). also, increase/decrease expressions (++, --) are supported. - 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] -examples: +S:NoType <= e:t -fib ---- -int n1 = 0; -int n2 = 1; -int n = readInt; -while(n-- > 0){ - int temp = n1+n2; - n1 = n2; - n2 = temp; -} -print n2; +[SIf] +T+ if e then s1 else s2 <= T+ e:bool & T+ s1 & T+ s2 -tests while, decr and assignment. +[SWhile] +T+ while e do s <= T+ e:bool & T+ s -if --- -if (readBool) { - if (readInt < 0) - print true; - else - print false; -} +[SDecl] -tests if and if/else. +T+ i:t => T', i:t <= i!ET & e:t & u:t +(Type u Ident i = Exp e) -sum ---- -int n; -int sum = 0; -while ((n = readInt) != -1) sum = sum + n; -print sum; -var ---- -int a = 3; -int b = a - 5; -int c = a + b*7; -bool d = a == b; -tests simple variable operations. \ No newline at end of file