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Module Ast

module Ast: sig .. end

Abstract Syntax of Mini-Python

Parsed trees

This is the output of the parser and the input of the type checker.

type location = Stdlib.Lexing.position * Stdlib.Lexing.position 
type ident = {
   loc : location;
   id : string;
} 
type unop =
| Uneg (*

-e

*)
| Unot (*

not e

*) 
type binop =
| Badd
| Bsub
| Bmul
| Bdiv
| Bmod (*

+ - * // %

*)
| Beq
| Bneq
| Blt
| Ble
| Bgt
| Bge (*

== != < <= > >=

*)
| Band
| Bor (*

and or

*) 
type constant =
| Cnone
| Cbool of bool
| Cstring of string
| Cint of int64 
type expr =
| Ecst of constant
| Eident of ident
| Ebinop of binop * expr * expr
| Eunop of unop * expr
| Ecall of ident * expr list
| Elist of expr list (*
 [e1,e2,...]
*)
| Eget of expr * expr (*
 e1[e2]
*) 
type stmt =
| Sif of expr * stmt * stmt
| Sreturn of expr
| Sassign of ident * expr
| Sprint of expr
| Sblock of stmt list
| Sfor of ident * expr * stmt
| Seval of expr
| Sset of expr * expr * expr (*
 e1[e2] = e3
*) 
type def = ident * ident list * stmt 
type file = def list * stmt

Typed trees

This is the output of the type checker and the input of the code generation.

type var = {
   v_name : string;
   mutable v_ofs : int; (*

position wrt %rbp

*)
}

In the typed trees, all the occurrences of the same variable point to a single record of the following type.

type fn = {
   fn_name : string;
   fn_params : var list;
}

Similarly, all the occurrences of a given function all point to a single record of the following type.

type texpr =
| TEcst of constant
| TEvar of var
| TEbinop of binop * texpr * texpr
| TEunop of unop * texpr
| TEcall of fn * texpr list
| TElist of texpr list
| TErange of texpr (*

list(range(e1))

*)
| TEget of texpr * texpr (*
 e1[e2]
*) 
type tstmt =
| TSif of texpr * tstmt * tstmt
| TSreturn of texpr
| TSassign of var * texpr
| TSprint of texpr
| TSblock of tstmt list
| TSfor of var * texpr * tstmt
| TSeval of texpr
| TSset of texpr * texpr * texpr (*
 e1[e2] = e3
*) 
type tdef = fn * tstmt 
type tfile = tdef list

the block of global statements is now a `main` function