Reverse Polish Notation🔗ℹ

Reverse Polish Notation (RPN) is a way of writing expressions commonly found in calculators and Forth-like programming languages. In RPN, an expression is a list of instructions for manipulating data on a stack. The most basic instruction is to push a value onto the stack. Function call instructions pop a function’s arguments off the stack and push its results onto the stack. The rpn library represents an RPN program as a call to the rpn function with the program instructions as arguments.

1 RPN Stacks🔗ℹ

procedure (rpn-stack? v) → boolean?

v : any/c

value empty-rpn-stack : rpn-stack? = (rpn)

procedure (rpn-stack-push stack instruction) → rpn-stack?

stack : rpn-stack?

instruction : rpn-instruction?

2 RPN Instructions🔗ℹ

procedure (rpn-instruction? v) → boolean?

v : any/c

2.1 Pushing Operands🔗ℹ

2.2 Calling Operators🔗ℹ

procedure (rpn-operator? v) → boolean?

v : any/c

procedure (binary-rpn-operator binary-function) → rpn-operator?

binary-function : (-> any/c any/c any/c)

procedure (rpn-operator   #:function function             #:input-arity input-arity             #:output-arity output-arity)   →   rpn-operator?

function : procedure?

input-arity : natural?

output-arity : natural?

2.3 Arithmetic Operators🔗ℹ

3 RPN Notation🔗ℹ

procedure (rpn instruction ...) → rpn-stack?

instruction : any/c

4 Streaming RPN Computations🔗ℹ

value into-rpn : reducer?