These functions output a printed representation of a CPS term (expression or definition). One problem of the CPS representation is that it is difficult to read, especially because of the deep level of nesting. We tried to simplify this representation by not showing the nesting explicitely to the user; instead a parent always has the same level of indentation than its children in the tree. The syntax looks a lot like assembly language, or SSA representation.
Still, this representation could be readily parsed back into a CPS
data structure if needed.
open Format
let rec var ppf v = fprintf ppf "%s" (Var.Var.to_string v)
and occur ppf v = fprintf ppf "%s" (Var.Occur.to_string v)
and cont_var ppf v = fprintf ppf "%s" (Cont_var.Var.to_string v)
and cont_occur ppf v = fprintf ppf "%s" (Cont_var.Occur.to_string v)
and var_list ppf vl = (Make_printer.list ~sep:", " var) ppf vl
and occur_list ppf vl = (Make_printer.list ~sep:", " occur) ppf vl
and expression ppf t = match Expression.get t with
∣ Halt v →
fprintf ppf "halt %a" occur v
∣ Apply(_,callerv,k,callees) →
fprintf ppf "%a( %a, %a)"
occur callerv cont_occur k occur_list callees
∣ Apply_cont(k,v) →
fprintf ppf "%a( %a)"
cont_occur k occur v
∣ Let_cont(k,v,loccont,incont) →
fprintf ppf "decl %a" cont_var k;
let rec loop accu e = match Expression.get e with
∣ Let_cont(k,v,loccont,incont) →
fprintf ppf ", %a" cont_var k;
loop ((k,v,loccont)::accu) incont
∣ final_incont →
fprintf ppf "@\n@[<v>%a@]" expression e;
List.iter (fun (k,v,cont) →
fprintf ppf "@\n@\n%a( %a) = {@\n @[<v>%a@]@\n}"
cont_var k var v expression cont)
accu
in loop [k,v,loccont] incont
∣ Let_prim(v,p,body) →
fprintf ppf "@[<v>let %a = %a in@ %a@]"
var v prim p expression body
∣ Case(v,l,d) →
let case ppf (i,k) = fprintf ppf "%d -> %a" i cont_occur k in
let case_list ppf l = Make_printer.list ~sep:"@\n" case ppf l in
let default ppf d =
(match d with
∣ None → ()
∣ Some(k) → fprintf ppf "@\n_ -> %a" cont_occur k) in
fprintf ppf "case(%a){@\n @[<v>%a%a@]@\n}"
occur v case_list (CaseMap.bindings l) default d
and prim ppf = function
∣ Value v → value ppf v
∣ Projection(i,x) →
fprintf ppf "#%d( %a)"
i occur x
∣ Integer_binary_operation(op,v1,v2) →
fprintf ppf "%s( %a, %a)"
(Constant.integer_binary_operation_to_string op) occur v1 occur v2
∣ Integer_binary_predicate(pred,v1,v2) →
fprintf ppf "%s( %a, %a)"
(Constant.integer_binary_predicate_to_string pred) occur v1 occur v2
and value ppf = function
∣ Constant(c) →
fprintf ppf "%s" (Constant.to_string c)
∣ Tuple(l) →
fprintf ppf "( %a)" occur_list l
∣ Injection(i,j,x) → fprintf ppf "inj_{%d/%d}( %a)" i j occur x
∣ Lambda(_,k,vl,expression_) →
fprintf ppf "@,@[<v>{ @[<v>%a -> (%a) ->@\n@[<v>%a@]@]@\n}@]"
cont_var k var_list vl expression expression_
∣ External(str) → fprintf ppf "external( \"%s\")" str
let rec definition ppf (Definition(v,dt)) =
fprintf ppf "%a = @[%a@]" visibility v definition_type dt
and visibility ppf = function
∣ Public(v) → fprintf ppf "def %a" var v
∣ Private(v) → fprintf ppf "let %a" var v
∣ Unused → fprintf ppf "let _"
and definition_type ppf = function
∣ Static_value(_) → failwith "Not yet implemented"
∣ Dynamic_value(t) → expression ppf t
let definitions ppf l =
List.iter (fun def → definition ppf def; fprintf ppf "@.") l
let debug_expression t =
Format.eprintf "----------------------------------------\n";
Format.eprintf "%a\n" expression t;
Format.eprintf "----------------------------------------\n@?"