Bobcat -- A language that is like Tiger , but smaller and less frightening.

Bobcat is designed to let us look at some issues of compiling expressions, flow control statements, and local variables, while ignoring many of the more sophisticated issues that arise in a complete compiler such as the Tiger compiler for CS350. Bobcat is, for the most part, a subset of Tiger.

Bobcat language guide

A Bobcat program is made up of a sequence of variable and function declarations, with comments allowed anywhere whitespace is allowed. Comments are any text within /* and */ (possibly multiple lines). Declarations have the form

var name : type

var name : type := expression

(for a variable), or

function name ( name: type, name : type ... ) =

(

expression;

expression;

...

)

(for a function). A type may be either int or double ; An expression may be any of the following:

• A constant such as 17 or 3.14159.
• A variable that is in scope (either a global or a parameter).
• A non-destructive binary C operation such as +, -, *, /, %, &&, &, >, ==, etc, applied to two (possibly parenthesized) subexpressions.
• An assignment var := expression; As in C, the value of the assignment expression is the value assigned.
• if expression then expression else expression (the first expression must have type int; if it is zero, the value is given by the third expression; if not, the value is given by the second expression).
• while expression do expression (the second expression is repeatedly evaluated, as long as the first (which must have type int) is non-zero). The result is always zero.
• name(expression, expression, ...), which calls the named function. The result is the value of the last expression given in the function.