diff options
| author |  rustanleino <unknown> | 2010-11-06 19:47:03 +0000 |
|---|---|---|
| committer | rustanleino <unknown> | 2010-11-06 19:47:03 +0000 |
| commit | ea1898f88e2edcecf3a58923fcd1a5d2b87219a8 (patch) | |
| tree | 82944147dd136bf68b4cb2f8e40d440c6705d42e /Source/Forro/Printer.fs | |
| parent | 8d1dd0f01a78bf29aa98832317d8fc951ed15075 (diff) | |
Introducing Forr?! Forr? is a tiny language that translates to Boogie. The purpose of the language and verifier is to serve as a tutorial example for how to build a verifier on top of Boogie.
Diffstat (limited to 'Source/Forro/Printer.fs')
| -rw-r--r-- | Source/Forro/Printer.fs | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/Source/Forro/Printer.fs b/Source/Forro/Printer.fs new file mode 100644 index 00000000..65d515f8 --- /dev/null +++ b/Source/Forro/Printer.fs @@ -0,0 +1,110 @@ +module ForroPrinter
+
+open System
+open Forro
+
+let rec PrintVars xs =
+ match xs with
+ | [] -> ()
+ | Var(x)::rest -> printf " %s" x ; PrintVars rest
+
+let PrintField f =
+ printf "."
+ match f with
+ | Head -> printf "head"
+ | Tail -> printf "tail"
+ | Valid -> printf "valid"
+
+let PrintOp op =
+ printf " "
+ match op with
+ | Eq -> printf "=="
+ | Neq -> printf "!="
+ | Plus -> printf "+"
+ | Minus -> printf "-"
+ | Times -> printf "*"
+ | Less -> printf "<"
+ | AtMost -> printf "<="
+ | And -> printf "and"
+ | Or -> printf "or"
+ printf " "
+
+let rec PrintExpr e outermost =
+ match e with
+ | Constant(x) -> printf "%i" x
+ | Null -> printf "null"
+ | Identifier(Var(x)) -> printf "%s" x
+ | Not(e) -> printf "not(" ; PrintExpr e true ; printf ")"
+ | Binary(op,a,b) ->
+ if outermost then () else printf "("
+ PrintExpr a false ; PrintOp op ; PrintExpr b false
+ if outermost then () else printf ")"
+ | Select(e,f) -> PrintExpr e false ; PrintField f
+ | Old(e) -> printf "old(" ; PrintExpr e true ; printf ")"
+
+let rec Indent n =
+ if n = 0 then () else printf " " ; Indent (n-1)
+
+let rec PrintStmt indent s =
+ Indent indent
+ let ind = indent + 2
+ match s with
+ | Assign(Var(x), e) -> printf "%s" x ; printf " := " ; PrintExpr e true
+ | Update(obj,f,rhs) -> PrintExpr obj false ; PrintField f ; printf " := " ; PrintExpr rhs true
+ | Alloc(Var(x),hd,tl) -> printf "%s" x ; printf " := new " ; PrintExpr hd false ; printf " " ; PrintExpr tl false
+ | IfStmt(guard,thn,els) ->
+ printf "if " ; PrintExpr guard true ; printfn " then"
+ PrintStmtList ind thn
+ Indent indent ; printfn "else"
+ PrintStmtList ind els
+ Indent indent ; printf "end"
+ | WhileStmt(guard,invs,body) ->
+ printf "while " ; PrintExpr guard true ; printfn ""
+ List.iter (fun inv -> Indent ind ; printf "invariant " ; PrintExpr inv true ; printfn "") invs
+ Indent indent ; printfn "do"
+ PrintStmtList ind body
+ Indent indent ; printf "end"
+ | CallStmt(outs,id,ins) ->
+ printf "call"
+ if outs.IsEmpty then () else PrintVars outs ; printf " :="
+ printf " %s" id
+ printf "("
+ ignore (List.fold (fun sep e -> printf "%s" sep ; PrintExpr e false ; " ") "" ins)
+ printf ");"
+ | Assert(e) ->
+ printf "assert " ; PrintExpr e ; printfn ";"
+ printfn ";"
+
+and PrintStmtList indent slist =
+ match slist with
+ | Block(ss) -> List.iter (fun s -> PrintStmt indent s) ss
+
+let PrintProc p =
+ match p with
+ | Proc(name, ins, outs, req, ens, body) ->
+ // signature
+ printf "procedure"
+ if outs.IsEmpty then () else PrintVars outs ; printf " :="
+ printf " %s" name
+ PrintVars ins
+ printfn ""
+ // specification
+ printf " requires "
+ PrintExpr req true
+ printfn ""
+ printf " ensures "
+ PrintExpr ens true
+ printfn ""
+ // body
+ printfn "do"
+ PrintStmtList 2 body
+ printfn "end;"
+
+let rec PrintProcs ps =
+ match ps with
+ | [] -> ()
+ | p::rest -> PrintProc p ; PrintProcs rest
+
+let Print prog =
+ match prog with
+ | Prog(procs) -> PrintProcs procs
|