open Common;; open Token;; open Parser;; (* NB: pexps (parser-expressions) are only used transiently during * parsing, static-evaluation and syntax-expansion. They're desugared * into the general "item" AST and/or evaluated as part of the * outermost "cexp" expressions. Expressions that can show up in source * correspond to this loose grammar and have a wide-ish flexibility in * *theoretical* composition; only subsets of those compositions are * legal in various AST contexts. * * Desugaring on the fly is unfortunately complicated enough to require * -- or at least "make much more convenient" -- this two-pass * routine. *) type pexp' = PEXP_call of (pexp * pexp array) | PEXP_spawn of (Ast.domain * pexp) | PEXP_bind of (pexp * pexp option array) | PEXP_rec of ((Ast.ident * pexp) array * pexp option) | PEXP_tup of (pexp array) | PEXP_vec of (pexp array) | PEXP_port | PEXP_chan of (pexp option) | PEXP_binop of (Ast.binop * pexp * pexp) | PEXP_lazy_and of (pexp * pexp) | PEXP_lazy_or of (pexp * pexp) | PEXP_unop of (Ast.unop * pexp) | PEXP_lval of plval | PEXP_lit of Ast.lit | PEXP_str of string | PEXP_mutable of pexp | PEXP_exterior of pexp | PEXP_custom of Ast.name * (pexp array) * (string option) and plval = PLVAL_ident of Ast.ident | PLVAL_app of (Ast.ident * (Ast.ty array)) | PLVAL_ext_name of (pexp * Ast.name_component) | PLVAL_ext_pexp of (pexp * pexp) and pexp = pexp' Common.identified ;; (* Pexp grammar. Includes names, idents, types, constrs, binops and unops, etc. *) let parse_ident (ps:pstate) : Ast.ident = match peek ps with IDENT id -> (bump ps; id) (* Decay IDX tokens to identifiers if they occur ousdide name paths. *) | IDX i -> (bump ps; string_of_tok (IDX i)) | _ -> raise (unexpected ps) ;; (* Enforces the restricted pexp grammar when applicable (e.g. after "bind") *) let check_rstr_start (ps:pstate) : 'a = if (ps.pstate_rstr) then match peek ps with IDENT _ | LPAREN -> () | _ -> raise (unexpected ps) ;; let rec parse_name_component (ps:pstate) : Ast.name_component = match peek ps with IDENT id -> (bump ps; match peek ps with LBRACKET -> let tys = ctxt "name_component: apply" (bracketed_one_or_more LBRACKET RBRACKET (Some COMMA) parse_ty) ps in Ast.COMP_app (id, tys) | _ -> Ast.COMP_ident id) | IDX i -> bump ps; Ast.COMP_idx i | _ -> raise (unexpected ps) and parse_name_base (ps:pstate) : Ast.name_base = match peek ps with IDENT i -> (bump ps; match peek ps with LBRACKET -> let tys = ctxt "name_base: apply" (bracketed_one_or_more LBRACKET RBRACKET (Some COMMA) parse_ty) ps in Ast.BASE_app (i, tys) | _ -> Ast.BASE_ident i) | _ -> raise (unexpected ps) and parse_name_ext (ps:pstate) (base:Ast.name) : Ast.name = match peek ps with DOT -> bump ps; let comps = one_or_more DOT parse_name_component ps in Array.fold_left (fun x y -> Ast.NAME_ext (x, y)) base comps | _ -> base and parse_name (ps:pstate) : Ast.name = let base = Ast.NAME_base (parse_name_base ps) in let name = parse_name_ext ps base in if Ast.sane_name name then name else raise (err "malformed name" ps) and parse_carg_base (ps:pstate) : Ast.carg_base = match peek ps with STAR -> bump ps; Ast.BASE_formal | _ -> Ast.BASE_named (parse_name_base ps) and parse_carg (ps:pstate) : Ast.carg = match peek ps with IDENT _ -> begin let base = Ast.CARG_base (parse_carg_base ps) in let path = match peek ps with DOT -> bump ps; let comps = one_or_more DOT parse_name_component ps in Array.fold_left (fun x y -> Ast.CARG_ext (x, y)) base comps | _ -> base in Ast.CARG_path path end | _ -> Ast.CARG_lit (parse_lit ps) and parse_constraint (ps:pstate) : Ast.constr = match peek ps with (* * NB: A constraint *looks* a lot like an EXPR_call, but is restricted * syntactically: the constraint name needs to be a name (not an lval) * and the constraint args all need to be cargs, which are similar to * names but can begin with the 'formal' base anchor '*'. *) IDENT _ -> let n = ctxt "constraint: name" parse_name ps in let args = ctxt "constraint: args" (bracketed_zero_or_more LPAREN RPAREN (Some COMMA) parse_carg) ps in { Ast.constr_name = n; Ast.constr_args = args } | _ -> raise (unexpected ps) and parse_constrs (ps:pstate) : Ast.constrs = ctxt "state: constraints" (one_or_more COMMA parse_constraint) ps and parse_optional_trailing_constrs (ps:pstate) : Ast.constrs = match peek ps with COLON -> (bump ps; parse_constrs ps) | _ -> [| |] and parse_effect (ps:pstate) : Ast.effect = match peek ps with IO -> bump ps; Ast.IO | STATE -> bump ps; Ast.STATE | UNSAFE -> bump ps; Ast.UNSAFE | _ -> Ast.PURE and parse_ty_fn (effect:Ast.effect) (ps:pstate) : (Ast.ty_fn * Ast.ident option) = match peek ps with FN | ITER -> let is_iter = (peek ps) = ITER in bump ps; let ident = match peek ps with IDENT i -> bump ps; Some i | _ -> None in let in_slots = match peek ps with _ -> bracketed_zero_or_more LPAREN RPAREN (Some COMMA) (parse_slot_and_optional_ignored_ident true) ps in let out_slot = match peek ps with RARROW -> (bump ps; parse_slot false ps) | _ -> slot_nil in let constrs = parse_optional_trailing_constrs ps in let tsig = { Ast.sig_input_slots = in_slots; Ast.sig_input_constrs = constrs; Ast.sig_output_slot = out_slot; } in let taux = { Ast.fn_effect = effect; Ast.fn_is_iter = is_iter; } in let tfn = (tsig, taux) in (tfn, ident) | _ -> raise (unexpected ps) and check_dup_rec_labels ps labels = arr_check_dups labels (fun l _ -> raise (err (Printf.sprintf "duplicate record label: %s" l) ps)); and parse_atomic_ty (ps:pstate) : Ast.ty = match peek ps with BOOL -> bump ps; Ast.TY_bool | INT -> bump ps; Ast.TY_int | UINT -> bump ps; Ast.TY_uint | CHAR -> bump ps; Ast.TY_char | STR -> bump ps; Ast.TY_str | ANY -> bump ps; Ast.TY_any | TASK -> bump ps; Ast.TY_task | CHAN -> bump ps; Ast.TY_chan (bracketed LBRACKET RBRACKET parse_ty ps) | PORT -> bump ps; Ast.TY_port (bracketed LBRACKET RBRACKET parse_ty ps) | VEC -> bump ps; Ast.TY_vec (bracketed LBRACKET RBRACKET parse_ty ps) | IDENT _ -> Ast.TY_named (parse_name ps) | TAG -> bump ps; let htab = Hashtbl.create 4 in let parse_tag_entry ps = let ident = parse_ident ps in let tup = match peek ps with LPAREN -> paren_comma_list parse_ty ps | _ -> raise (err "tag variant missing argument list" ps) in htab_put htab (Ast.NAME_base (Ast.BASE_ident ident)) tup in let _ = bracketed_one_or_more LPAREN RPAREN (Some COMMA) (ctxt "tag: variant" parse_tag_entry) ps in Ast.TY_tag htab | REC -> bump ps; let parse_rec_entry ps = let (ty, ident) = parse_ty_and_ident ps in (ident, ty) in let entries = paren_comma_list parse_rec_entry ps in let labels = Array.map (fun (l, _) -> l) entries in begin check_dup_rec_labels ps labels; Ast.TY_rec entries end | TUP -> bump ps; let tys = paren_comma_list parse_ty ps in Ast.TY_tup tys | MACH m -> bump ps; Ast.TY_mach m | IO | STATE | UNSAFE | OBJ | FN | ITER -> let effect = parse_effect ps in begin match peek ps with OBJ -> bump ps; let methods = Hashtbl.create 0 in let parse_method ps = let effect = parse_effect ps in let (tfn, ident) = parse_ty_fn effect ps in expect ps SEMI; match ident with None -> raise (err (Printf.sprintf "missing method identifier") ps) | Some i -> htab_put methods i tfn in ignore (bracketed_zero_or_more LBRACE RBRACE None parse_method ps); Ast.TY_obj (effect, methods) | FN | ITER -> Ast.TY_fn (fst (parse_ty_fn effect ps)) | _ -> raise (unexpected ps) end | AT -> bump ps; Ast.TY_exterior (parse_ty ps) | MUTABLE -> bump ps; Ast.TY_mutable (parse_ty ps) | LPAREN -> begin bump ps; match peek ps with RPAREN -> bump ps; Ast.TY_nil | _ -> let t = parse_ty ps in expect ps RPAREN; t end | _ -> raise (unexpected ps) and flag (ps:pstate) (tok:token) : bool = if peek ps = tok then (bump ps; true) else false and parse_mutability (ps:pstate) : bool = flag ps MUTABLE and parse_slot (aliases_ok:bool) (ps:pstate) : Ast.slot = let mode = match (peek ps, aliases_ok) with (AND, true) -> bump ps; Ast.MODE_alias | (AND, false) -> raise (err "alias slot in prohibited context" ps) | _ -> Ast.MODE_interior in let ty = parse_ty ps in { Ast.slot_mode = mode; Ast.slot_ty = Some ty } and parse_slot_and_ident (aliases_ok:bool) (ps:pstate) : (Ast.slot * Ast.ident) = let slot = ctxt "slot and ident: slot" (parse_slot aliases_ok) ps in let ident = ctxt "slot and ident: ident" parse_ident ps in (slot, ident) and parse_ty_and_ident (ps:pstate) : (Ast.ty * Ast.ident) = let ty = ctxt "ty and ident: ty" parse_ty ps in let ident = ctxt "ty and ident: ident" parse_ident ps in (ty, ident) and parse_slot_and_optional_ignored_ident (aliases_ok:bool) (ps:pstate) : Ast.slot = let slot = parse_slot aliases_ok ps in begin match peek ps with IDENT _ -> bump ps | _ -> () end; slot and parse_identified_slot (aliases_ok:bool) (ps:pstate) : Ast.slot identified = let apos = lexpos ps in let slot = parse_slot aliases_ok ps in let bpos = lexpos ps in span ps apos bpos slot and parse_constrained_ty (ps:pstate) : Ast.ty = let base = ctxt "ty: base" parse_atomic_ty ps in match peek ps with COLON -> bump ps; let constrs = ctxt "ty: constrs" parse_constrs ps in Ast.TY_constrained (base, constrs) | _ -> base and parse_ty (ps:pstate) : Ast.ty = parse_constrained_ty ps and parse_rec_input (ps:pstate) : (Ast.ident * pexp) = let lab = (ctxt "rec input: label" parse_ident ps) in match peek ps with EQ -> bump ps; let pexp = ctxt "rec input: expr" parse_pexp ps in (lab, pexp) | _ -> raise (unexpected ps) and parse_rec_body (ps:pstate) : pexp' = (*((Ast.ident * pexp) array) =*) begin expect ps LPAREN; match peek ps with RPAREN -> PEXP_rec ([||], None) | WITH -> raise (err "empty record extension" ps) | _ -> let inputs = one_or_more COMMA parse_rec_input ps in let labels = Array.map (fun (l, _) -> l) inputs in begin check_dup_rec_labels ps labels; match peek ps with RPAREN -> (bump ps; PEXP_rec (inputs, None)) | WITH -> begin bump ps; let base = ctxt "rec input: extension base" parse_pexp ps in expect ps RPAREN; PEXP_rec (inputs, Some base) end | _ -> raise (err "expected 'with' or ')'" ps) end end and parse_lit (ps:pstate) : Ast.lit = match peek ps with LIT_INT (n,s) -> (bump ps; Ast.LIT_int (n,s)) | LIT_CHAR c -> (bump ps; Ast.LIT_char c) | LIT_BOOL b -> (bump ps; Ast.LIT_bool b) | _ -> raise (unexpected ps) and parse_bottom_pexp (ps:pstate) : pexp = check_rstr_start ps; let apos = lexpos ps in match peek ps with MUTABLE -> bump ps; let inner = parse_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_mutable inner) | AT -> bump ps; let inner = parse_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_exterior inner) | TUP -> bump ps; let pexps = ctxt "paren pexps(s)" (rstr false parse_pexp_list) ps in let bpos = lexpos ps in span ps apos bpos (PEXP_tup pexps) | REC -> bump ps; let body = ctxt "rec pexp: rec body" parse_rec_body ps in let bpos = lexpos ps in span ps apos bpos body | VEC -> bump ps; begin let pexps = ctxt "vec pexp: exprs" parse_pexp_list ps in let bpos = lexpos ps in span ps apos bpos (PEXP_vec pexps) end | LIT_STR s -> bump ps; let bpos = lexpos ps in span ps apos bpos (PEXP_str s) | PORT -> begin bump ps; expect ps LPAREN; expect ps RPAREN; let bpos = lexpos ps in span ps apos bpos (PEXP_port) end | CHAN -> begin bump ps; let port = match peek ps with LPAREN -> begin bump ps; match peek ps with RPAREN -> (bump ps; None) | _ -> let lv = parse_pexp ps in expect ps RPAREN; Some lv end | _ -> raise (unexpected ps) in let bpos = lexpos ps in span ps apos bpos (PEXP_chan port) end | SPAWN -> bump ps; let domain = match peek ps with THREAD -> bump ps; Ast.DOMAIN_thread | _ -> Ast.DOMAIN_local in let pexp = ctxt "spawn [domain] pexp: init call" parse_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_spawn (domain, pexp)) | BIND -> let apos = lexpos ps in begin bump ps; let pexp = ctxt "bind pexp: function" (rstr true parse_pexp) ps in let args = ctxt "bind args" (paren_comma_list parse_bind_arg) ps in let bpos = lexpos ps in span ps apos bpos (PEXP_bind (pexp, args)) end | IDENT i -> begin bump ps; match peek ps with LBRACKET -> begin let tys = ctxt "apply-type expr" (bracketed_one_or_more LBRACKET RBRACKET (Some COMMA) parse_ty) ps in let bpos = lexpos ps in span ps apos bpos (PEXP_lval (PLVAL_app (i, tys))) end | _ -> begin let bpos = lexpos ps in span ps apos bpos (PEXP_lval (PLVAL_ident i)) end end | (INT | UINT | CHAR | BOOL) as tok -> begin bump ps; expect ps LPAREN; match peek ps with (LIT_INT _ | LIT_CHAR _ | LIT_BOOL _) as tok2 -> bump ps; expect ps RPAREN; let i = match tok2 with LIT_INT i -> i | LIT_CHAR c -> (Int64.of_int c, Common.escaped_char c) | LIT_BOOL b -> if b then (1L, "1") else (0L, "0") | _ -> bug () "expected int/char literal" in let bpos = lexpos ps in span ps apos bpos (PEXP_lit (match tok with INT -> Ast.LIT_int i | UINT -> Ast.LIT_uint i | CHAR -> Ast.LIT_char (Int64.to_int (fst i)) | BOOL -> Ast.LIT_bool (fst i <> 0L) | _ -> bug () "expected int/uint/char/bool token")) | _ -> let pexp = parse_pexp ps in expect ps RPAREN; let bpos = lexpos ps in let t = match tok with INT -> Ast.TY_int | UINT -> Ast.TY_uint | CHAR -> Ast.TY_char | BOOL -> Ast.TY_bool | _ -> bug () "expected int/uint/char/bool token" in let t = span ps apos bpos t in span ps apos bpos (PEXP_unop ((Ast.UNOP_cast t), pexp)) end | MACH m -> let literal (num, str) = let _ = bump ps in let _ = expect ps RPAREN in let bpos = lexpos ps in let check_range (lo:int64) (hi:int64) : unit = if (num < lo) or (num > hi) then raise (err (Printf.sprintf "integral literal %Ld out of range [%Ld,%Ld]" num lo hi) ps) else () in begin match m with TY_u8 -> check_range 0L 0xffL | TY_u16 -> check_range 0L 0xffffL | TY_u32 -> check_range 0L 0xffffffffL (* | TY_u64 -> ... *) | TY_i8 -> check_range (-128L) 127L | TY_i16 -> check_range (-32768L) 32767L | TY_i32 -> check_range (-2147483648L) 2147483647L (* | TY_i64 -> ... | TY_f32 -> ... | TY_f64 -> ... *) | _ -> () end; span ps apos bpos (PEXP_lit (Ast.LIT_mach (m, num, str))) in begin bump ps; expect ps LPAREN; match peek ps with LIT_INT (n,s) -> literal (n,s) | MINUS -> begin bump ps; match peek ps with LIT_INT (n,s) -> literal (Int64.neg n, "-" ^ s) | _ -> raise (unexpected ps) end | _ -> let pexp = parse_pexp ps in expect ps RPAREN; let bpos = lexpos ps in let t = span ps apos bpos (Ast.TY_mach m) in span ps apos bpos (PEXP_unop ((Ast.UNOP_cast t), pexp)) end | POUND -> bump ps; let name = parse_name ps in let args = match peek ps with LPAREN -> parse_pexp_list ps | _ -> [| |] in let str = match peek ps with LBRACE -> begin bump_bracequote ps; match peek ps with BRACEQUOTE s -> bump ps; Some s | _ -> raise (unexpected ps) end | _ -> None in let bpos = lexpos ps in span ps apos bpos (PEXP_custom (name, args, str)) | LPAREN -> begin bump ps; match peek ps with RPAREN -> bump ps; let bpos = lexpos ps in span ps apos bpos (PEXP_lit Ast.LIT_nil) | _ -> let pexp = parse_pexp ps in expect ps RPAREN; pexp end | _ -> let lit = parse_lit ps in let bpos = lexpos ps in span ps apos bpos (PEXP_lit lit) and parse_bind_arg (ps:pstate) : pexp option = match peek ps with UNDERSCORE -> (bump ps; None) | _ -> Some (parse_pexp ps) and parse_ext_pexp (ps:pstate) (pexp:pexp) : pexp = let apos = lexpos ps in match peek ps with LPAREN -> if ps.pstate_rstr then pexp else let args = parse_pexp_list ps in let bpos = lexpos ps in let ext = span ps apos bpos (PEXP_call (pexp, args)) in parse_ext_pexp ps ext | DOT -> begin bump ps; let ext = match peek ps with LPAREN -> bump ps; let rhs = rstr false parse_pexp ps in expect ps RPAREN; let bpos = lexpos ps in span ps apos bpos (PEXP_lval (PLVAL_ext_pexp (pexp, rhs))) | _ -> let rhs = parse_name_component ps in let bpos = lexpos ps in span ps apos bpos (PEXP_lval (PLVAL_ext_name (pexp, rhs))) in parse_ext_pexp ps ext end | _ -> pexp and parse_negation_pexp (ps:pstate) : pexp = let apos = lexpos ps in match peek ps with NOT -> bump ps; let rhs = ctxt "negation pexp" parse_negation_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_unop (Ast.UNOP_not, rhs)) | TILDE -> bump ps; let rhs = ctxt "negation pexp" parse_negation_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_unop (Ast.UNOP_bitnot, rhs)) | MINUS -> bump ps; let rhs = ctxt "negation pexp" parse_negation_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_unop (Ast.UNOP_neg, rhs)) | _ -> let lhs = parse_bottom_pexp ps in parse_ext_pexp ps lhs (* Binops are all left-associative, *) (* so we factor out some of the parsing code here. *) and binop_rhs (ps:pstate) (name:string) (apos:pos) (lhs:pexp) (rhs_parse_fn:pstate -> pexp) (op:Ast.binop) : pexp = bump ps; let rhs = (ctxt (name ^ " rhs") rhs_parse_fn ps) in let bpos = lexpos ps in span ps apos bpos (PEXP_binop (op, lhs, rhs)) and parse_factor_pexp (ps:pstate) : pexp = let name = "factor pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_negation_pexp ps in match peek ps with STAR -> binop_rhs ps name apos lhs parse_factor_pexp Ast.BINOP_mul | SLASH -> binop_rhs ps name apos lhs parse_factor_pexp Ast.BINOP_div | PERCENT -> binop_rhs ps name apos lhs parse_factor_pexp Ast.BINOP_mod | _ -> lhs and parse_term_pexp (ps:pstate) : pexp = let name = "term pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_factor_pexp ps in match peek ps with PLUS -> binop_rhs ps name apos lhs parse_term_pexp Ast.BINOP_add | MINUS -> binop_rhs ps name apos lhs parse_term_pexp Ast.BINOP_sub | _ -> lhs and parse_shift_pexp (ps:pstate) : pexp = let name = "shift pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_term_pexp ps in match peek ps with LSL -> binop_rhs ps name apos lhs parse_shift_pexp Ast.BINOP_lsl | LSR -> binop_rhs ps name apos lhs parse_shift_pexp Ast.BINOP_lsr | ASR -> binop_rhs ps name apos lhs parse_shift_pexp Ast.BINOP_asr | _ -> lhs and parse_and_pexp (ps:pstate) : pexp = let name = "and pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_shift_pexp ps in match peek ps with AND -> binop_rhs ps name apos lhs parse_and_pexp Ast.BINOP_and | _ -> lhs and parse_xor_pexp (ps:pstate) : pexp = let name = "xor pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_and_pexp ps in match peek ps with CARET -> binop_rhs ps name apos lhs parse_xor_pexp Ast.BINOP_xor | _ -> lhs and parse_or_pexp (ps:pstate) : pexp = let name = "or pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_xor_pexp ps in match peek ps with OR -> binop_rhs ps name apos lhs parse_or_pexp Ast.BINOP_or | _ -> lhs and parse_relational_pexp (ps:pstate) : pexp = let name = "relational pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_or_pexp ps in match peek ps with LT -> binop_rhs ps name apos lhs parse_relational_pexp Ast.BINOP_lt | LE -> binop_rhs ps name apos lhs parse_relational_pexp Ast.BINOP_le | GE -> binop_rhs ps name apos lhs parse_relational_pexp Ast.BINOP_ge | GT -> binop_rhs ps name apos lhs parse_relational_pexp Ast.BINOP_gt | _ -> lhs and parse_equality_pexp (ps:pstate) : pexp = let name = "equality pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_relational_pexp ps in match peek ps with EQEQ -> binop_rhs ps name apos lhs parse_equality_pexp Ast.BINOP_eq | NE -> binop_rhs ps name apos lhs parse_equality_pexp Ast.BINOP_ne | _ -> lhs and parse_andand_pexp (ps:pstate) : pexp = let name = "andand pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_equality_pexp ps in match peek ps with ANDAND -> bump ps; let rhs = parse_andand_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_lazy_and (lhs, rhs)) | _ -> lhs and parse_oror_pexp (ps:pstate) : pexp = let name = "oror pexp" in let apos = lexpos ps in let lhs = ctxt (name ^ " lhs") parse_andand_pexp ps in match peek ps with OROR -> bump ps; let rhs = parse_oror_pexp ps in let bpos = lexpos ps in span ps apos bpos (PEXP_lazy_or (lhs, rhs)) | _ -> lhs and parse_as_pexp (ps:pstate) : pexp = let apos = lexpos ps in let pexp = ctxt "as pexp" parse_oror_pexp ps in match peek ps with AS -> bump ps; let tapos = lexpos ps in let t = parse_ty ps in let bpos = lexpos ps in let t = span ps tapos bpos t in span ps apos bpos (PEXP_unop ((Ast.UNOP_cast t), pexp)) | _ -> pexp and parse_pexp (ps:pstate) : pexp = parse_as_pexp ps and parse_pexp_list (ps:pstate) : pexp array = match peek ps with LPAREN -> bracketed_zero_or_more LPAREN RPAREN (Some COMMA) (ctxt "pexp list" parse_pexp) ps | _ -> raise (unexpected ps) ;; (* * FIXME: This is a crude approximation of the syntax-extension system, * for purposes of prototyping and/or hard-wiring any extensions we * wish to use in the bootstrap compiler. The eventual aim is to permit * loading rust crates to process extensions, but this will likely * require a rust-based frontend, or an ocaml-FFI-based connection to * rust crates. At the moment we have neither. *) let expand_pexp_custom (ps:pstate) (dst_lval:Ast.lval) (name:Ast.name) (args:Ast.atom array) (body:string option) (spanner:'a -> 'a identified) : (Ast.stmt array) = let nstr = Fmt.fmt_to_str Ast.fmt_name name in match (nstr, (Array.length args), body) with ("shell", 0, Some cmd) -> let c = Unix.open_process_in cmd in let b = Buffer.create 32 in let rec r _ = try Buffer.add_char b (input_char c); r () with End_of_file -> ignore (Unix.close_process_in c); Buffer.contents b in [| spanner (Ast.STMT_init_str (dst_lval, r())) |] | _ -> raise (err ("unsupported syntax extension: " ^ nstr) ps) ;; (* * Desugarings depend on context: * * - If a pexp is used on the RHS of an assignment, it's turned into * an initialization statement such as STMT_init_rec or such. This * removes the possibility of initializing into a temp only to * copy out. If the topmost pexp in such a desugaring is an atom, * unop or binop, of course, it will still just emit a STMT_copy * on a primitive expression. * * - If a pexp is used in the context where an atom is required, a * statement declaring a temporary and initializing it with the * result of the pexp is prepended, and the temporary atom is used. *) let rec desugar_lval (ps:pstate) (pexp:pexp) : (Ast.stmt array * Ast.lval) = let s = Hashtbl.find ps.pstate_sess.Session.sess_spans pexp.id in let (apos, bpos) = (s.lo, s.hi) in match pexp.node with PEXP_lval (PLVAL_ident ident) -> let nb = span ps apos bpos (Ast.BASE_ident ident) in ([||], Ast.LVAL_base nb) | PEXP_lval (PLVAL_app (ident, tys)) -> let nb = span ps apos bpos (Ast.BASE_app (ident, tys)) in ([||], Ast.LVAL_base nb) | PEXP_lval (PLVAL_ext_name (base_pexp, comp)) -> let (base_stmts, base_atom) = desugar_expr_atom ps base_pexp in let base_lval = atom_lval ps base_atom in (base_stmts, Ast.LVAL_ext (base_lval, Ast.COMP_named comp)) | PEXP_lval (PLVAL_ext_pexp (base_pexp, ext_pexp)) -> let (base_stmts, base_atom) = desugar_expr_atom ps base_pexp in let (ext_stmts, ext_atom) = desugar_expr_atom ps ext_pexp in let base_lval = atom_lval ps base_atom in (Array.append base_stmts ext_stmts, Ast.LVAL_ext (base_lval, Ast.COMP_atom (clone_atom ps ext_atom))) | _ -> let (stmts, atom) = desugar_expr_atom ps pexp in (stmts, atom_lval ps atom) and desugar_expr (ps:pstate) (pexp:pexp) : (Ast.stmt array * Ast.expr) = match pexp.node with PEXP_unop (op, pe) -> let (stmts, at) = desugar_expr_atom ps pe in (stmts, Ast.EXPR_unary (op, at)) | PEXP_binop (op, lhs, rhs) -> let (lhs_stmts, lhs_atom) = desugar_expr_atom ps lhs in let (rhs_stmts, rhs_atom) = desugar_expr_atom ps rhs in (Array.append lhs_stmts rhs_stmts, Ast.EXPR_binary (op, lhs_atom, rhs_atom)) | _ -> let (stmts, at) = desugar_expr_atom ps pexp in (stmts, Ast.EXPR_atom at) and desugar_opt_expr_atom (ps:pstate) (po:pexp option) : (Ast.stmt array * Ast.atom option) = match po with None -> ([| |], None) | Some pexp -> let (stmts, atom) = desugar_expr_atom ps pexp in (stmts, Some atom) and desugar_expr_atom (ps:pstate) (pexp:pexp) : (Ast.stmt array * Ast.atom) = let s = Hashtbl.find ps.pstate_sess.Session.sess_spans pexp.id in let (apos, bpos) = (s.lo, s.hi) in match pexp.node with PEXP_unop _ | PEXP_binop _ | PEXP_lazy_or _ | PEXP_lazy_and _ | PEXP_rec _ | PEXP_tup _ | PEXP_str _ | PEXP_vec _ | PEXP_port | PEXP_chan _ | PEXP_call _ | PEXP_bind _ | PEXP_spawn _ | PEXP_custom _ | PEXP_exterior _ | PEXP_mutable _ -> let (_, tmp, decl_stmt) = build_tmp ps slot_auto apos bpos in let stmts = desugar_expr_init ps tmp pexp in (Array.append [| decl_stmt |] stmts, Ast.ATOM_lval (clone_lval ps tmp)) | PEXP_lit lit -> ([||], Ast.ATOM_literal (span ps apos bpos lit)) | PEXP_lval _ -> let (stmts, lval) = desugar_lval ps pexp in (stmts, Ast.ATOM_lval lval) and desugar_expr_atoms (ps:pstate) (pexps:pexp array) : (Ast.stmt array * Ast.atom array) = arj1st (Array.map (desugar_expr_atom ps) pexps) and desugar_opt_expr_atoms (ps:pstate) (pexps:pexp option array) : (Ast.stmt array * Ast.atom option array) = arj1st (Array.map (desugar_opt_expr_atom ps) pexps) and desugar_expr_init (ps:pstate) (dst_lval:Ast.lval) (pexp:pexp) : (Ast.stmt array) = let s = Hashtbl.find ps.pstate_sess.Session.sess_spans pexp.id in let (apos, bpos) = (s.lo, s.hi) in (* Helpers. *) let ss x = span ps apos bpos x in let cp v = Ast.STMT_copy (clone_lval ps dst_lval, v) in let aa x y = Array.append x y in let ac xs = Array.concat xs in match pexp.node with PEXP_lit _ | PEXP_lval _ -> let (stmts, atom) = desugar_expr_atom ps pexp in aa stmts [| ss (cp (Ast.EXPR_atom atom)) |] | PEXP_binop (op, lhs, rhs) -> let (lhs_stmts, lhs_atom) = desugar_expr_atom ps lhs in let (rhs_stmts, rhs_atom) = desugar_expr_atom ps rhs in let copy_stmt = ss (cp (Ast.EXPR_binary (op, lhs_atom, rhs_atom))) in ac [ lhs_stmts; rhs_stmts; [| copy_stmt |] ] (* x = a && b ==> if (a) { x = b; } else { x = false; } *) | PEXP_lazy_and (lhs, rhs) -> let (lhs_stmts, lhs_atom) = desugar_expr_atom ps lhs in let (rhs_stmts, rhs_atom) = desugar_expr_atom ps rhs in let sthen = ss (aa rhs_stmts [| ss (cp (Ast.EXPR_atom rhs_atom)) |]) in let selse = ss [| ss (cp (Ast.EXPR_atom (Ast.ATOM_literal (ss (Ast.LIT_bool false))))) |] in let sif = ss (Ast.STMT_if { Ast.if_test = Ast.EXPR_atom lhs_atom; Ast.if_then = sthen; Ast.if_else = Some selse }) in aa lhs_stmts [| sif |] (* x = a || b ==> if (a) { x = true; } else { x = b; } *) | PEXP_lazy_or (lhs, rhs) -> let (lhs_stmts, lhs_atom) = desugar_expr_atom ps lhs in let (rhs_stmts, rhs_atom) = desugar_expr_atom ps rhs in let sthen = ss [| ss (cp (Ast.EXPR_atom (Ast.ATOM_literal (ss (Ast.LIT_bool true))))) |] in let selse = ss (aa rhs_stmts [| ss (cp (Ast.EXPR_atom rhs_atom)) |]) in let sif = ss (Ast.STMT_if { Ast.if_test = Ast.EXPR_atom lhs_atom; Ast.if_then = sthen; Ast.if_else = Some selse }) in aa lhs_stmts [| sif |] | PEXP_unop (op, rhs) -> let (rhs_stmts, rhs_atom) = desugar_expr_atom ps rhs in let expr = Ast.EXPR_unary (op, rhs_atom) in let copy_stmt = ss (cp expr) in aa rhs_stmts [| copy_stmt |] | PEXP_call (fn, args) -> let (fn_stmts, fn_atom) = desugar_expr_atom ps fn in let (arg_stmts, arg_atoms) = desugar_expr_atoms ps args in let fn_lval = atom_lval ps fn_atom in let call_stmt = ss (Ast.STMT_call (dst_lval, fn_lval, arg_atoms)) in ac [ fn_stmts; arg_stmts; [| call_stmt |] ] | PEXP_bind (fn, args) -> let (fn_stmts, fn_atom) = desugar_expr_atom ps fn in let (arg_stmts, arg_atoms) = desugar_opt_expr_atoms ps args in let fn_lval = atom_lval ps fn_atom in let bind_stmt = ss (Ast.STMT_bind (dst_lval, fn_lval, arg_atoms)) in ac [ fn_stmts; arg_stmts; [| bind_stmt |] ] | PEXP_spawn (domain, sub) -> begin match sub.node with PEXP_call (fn, args) -> let (fn_stmts, fn_atom) = desugar_expr_atom ps fn in let (arg_stmts, arg_atoms) = desugar_expr_atoms ps args in let fn_lval = atom_lval ps fn_atom in let spawn_stmt = ss (Ast.STMT_spawn (dst_lval, domain, fn_lval, arg_atoms)) in ac [ fn_stmts; arg_stmts; [| spawn_stmt |] ] | _ -> raise (err "non-call spawn" ps) end | PEXP_rec (args, base) -> let (arg_stmts, entries) = arj1st begin Array.map begin fun (ident, pexp) -> let (stmts, atom) = desugar_expr_atom ps pexp in (stmts, (ident, atom)) end args end in begin match base with Some base -> let (base_stmts, base_lval) = desugar_lval ps base in let rec_stmt = ss (Ast.STMT_init_rec (dst_lval, entries, Some base_lval)) in ac [ arg_stmts; base_stmts; [| rec_stmt |] ] | None -> let rec_stmt = ss (Ast.STMT_init_rec (dst_lval, entries, None)) in aa arg_stmts [| rec_stmt |] end | PEXP_tup args -> let (arg_stmts, arg_atoms) = desugar_expr_atoms ps args in let stmt = ss (Ast.STMT_init_tup (dst_lval, arg_atoms)) in aa arg_stmts [| stmt |] | PEXP_str s -> let stmt = ss (Ast.STMT_init_str (dst_lval, s)) in [| stmt |] | PEXP_vec args -> let (arg_stmts, arg_atoms) = desugar_expr_atoms ps args in let stmt = ss (Ast.STMT_init_vec (dst_lval, arg_atoms)) in aa arg_stmts [| stmt |] | PEXP_port -> [| ss (Ast.STMT_init_port dst_lval) |] | PEXP_chan pexp_opt -> let (port_stmts, port_opt) = match pexp_opt with None -> ([||], None) | Some port_pexp -> begin let (port_stmts, port_atom) = desugar_expr_atom ps port_pexp in let port_lval = atom_lval ps port_atom in (port_stmts, Some port_lval) end in let chan_stmt = ss (Ast.STMT_init_chan (dst_lval, port_opt)) in aa port_stmts [| chan_stmt |] | PEXP_exterior arg -> let (arg_stmts, arg_mode_atom) = desugar_expr_atom ps arg in let stmt = ss (Ast.STMT_init_exterior (dst_lval, arg_mode_atom)) in aa arg_stmts [| stmt |] | PEXP_mutable arg -> (* Initializing a local from a "mutable" atom is the same as * initializing it from an immutable one; all locals are mutable * anyways. So this is just a fall-through. *) desugar_expr_init ps dst_lval arg | PEXP_custom (n, a, b) -> let (arg_stmts, args) = desugar_expr_atoms ps a in let stmts = expand_pexp_custom ps dst_lval n args b ss in aa arg_stmts stmts and atom_lval (ps:pstate) (at:Ast.atom) : Ast.lval = match at with Ast.ATOM_lval lv -> lv | Ast.ATOM_literal _ -> raise (err "literal where lval expected" ps) ;; (* * Local Variables: * fill-column: 78; * indent-tabs-mode: nil * buffer-file-coding-system: utf-8-unix * compile-command: "make -k -C ../.. 2>&1 | sed -e 's/\\/x\\//x:\\//g'"; * End: *)