llvm-65816/examples/OCaml-Kaleidoscope/Chapter4/ast.ml

26 lines
886 B
Standard ML

(*===----------------------------------------------------------------------===
* Abstract Syntax Tree (aka Parse Tree)
*===----------------------------------------------------------------------===*)
(* expr - Base type for all expression nodes. *)
type expr =
(* variant for numeric literals like "1.0". *)
| Number of float
(* variant for referencing a variable, like "a". *)
| Variable of string
(* variant for a binary operator. *)
| Binary of char * expr * expr
(* variant for function calls. *)
| Call of string * expr array
(* proto - This type represents the "prototype" for a function, which captures
* its name, and its argument names (thus implicitly the number of arguments the
* function takes). *)
type proto = Prototype of string * string array
(* func - This type represents a function definition itself. *)
type func = Function of proto * expr