examples/OCaml-Kaleidoscope/Chapter5/ast.ml

   1 (*===----------------------------------------------------------------------===
   2  * Abstract Syntax Tree (aka Parse Tree)
   3  *===----------------------------------------------------------------------===*)
   4
   5 (* expr - Base type for all expression nodes. *)
   6 type expr =
   7   (* variant for numeric literals like "1.0". *)
   8   | Number of float
   9
  10   (* variant for referencing a variable, like "a". *)
  11   | Variable of string
  12
  13   (* variant for a binary operator. *)
  14   | Binary of char * expr * expr
  15
  16   (* variant for function calls. *)
  17   | Call of string * expr array
  18
  19   (* variant for if/then/else. *)
  20   | If of expr * expr * expr
  21
  22   (* variant for for/in. *)
  23   | For of string * expr * expr * expr option * expr
  24
  25 (* proto - This type represents the "prototype" for a function, which captures
  26  * its name, and its argument names (thus implicitly the number of arguments the
  27  * function takes). *)
  28 type proto = Prototype of string * string array
  29
  30 (* func - This type represents a function definition itself. *)
  31 type func = Function of proto * expr