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Diffstat (limited to 'contrib/llvm/examples/OCaml-Kaleidoscope/Chapter6/parser.ml')
| -rw-r--r-- | contrib/llvm/examples/OCaml-Kaleidoscope/Chapter6/parser.ml | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/contrib/llvm/examples/OCaml-Kaleidoscope/Chapter6/parser.ml b/contrib/llvm/examples/OCaml-Kaleidoscope/Chapter6/parser.ml deleted file mode 100644 index da443c5..0000000 --- a/contrib/llvm/examples/OCaml-Kaleidoscope/Chapter6/parser.ml +++ /dev/null @@ -1,195 +0,0 @@ -(*===---------------------------------------------------------------------=== - * Parser - *===---------------------------------------------------------------------===*) - -(* binop_precedence - This holds the precedence for each binary operator that is - * defined *) -let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10 - -(* precedence - Get the precedence of the pending binary operator token. *) -let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1 - -(* primary - * ::= identifier - * ::= numberexpr - * ::= parenexpr - * ::= ifexpr - * ::= forexpr *) -let rec parse_primary = parser - (* numberexpr ::= number *) - | [< 'Token.Number n >] -> Ast.Number n - - (* parenexpr ::= '(' expression ')' *) - | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e - - (* identifierexpr - * ::= identifier - * ::= identifier '(' argumentexpr ')' *) - | [< 'Token.Ident id; stream >] -> - let rec parse_args accumulator = parser - | [< e=parse_expr; stream >] -> - begin parser - | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e - | [< >] -> e :: accumulator - end stream - | [< >] -> accumulator - in - let rec parse_ident id = parser - (* Call. *) - | [< 'Token.Kwd '('; - args=parse_args []; - 'Token.Kwd ')' ?? "expected ')'">] -> - Ast.Call (id, Array.of_list (List.rev args)) - - (* Simple variable ref. *) - | [< >] -> Ast.Variable id - in - parse_ident id stream - - (* ifexpr ::= 'if' expr 'then' expr 'else' expr *) - | [< 'Token.If; c=parse_expr; - 'Token.Then ?? "expected 'then'"; t=parse_expr; - 'Token.Else ?? "expected 'else'"; e=parse_expr >] -> - Ast.If (c, t, e) - - (* forexpr - ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression *) - | [< 'Token.For; - 'Token.Ident id ?? "expected identifier after for"; - 'Token.Kwd '=' ?? "expected '=' after for"; - stream >] -> - begin parser - | [< - start=parse_expr; - 'Token.Kwd ',' ?? "expected ',' after for"; - end_=parse_expr; - stream >] -> - let step = - begin parser - | [< 'Token.Kwd ','; step=parse_expr >] -> Some step - | [< >] -> None - end stream - in - begin parser - | [< 'Token.In; body=parse_expr >] -> - Ast.For (id, start, end_, step, body) - | [< >] -> - raise (Stream.Error "expected 'in' after for") - end stream - | [< >] -> - raise (Stream.Error "expected '=' after for") - end stream - - | [< >] -> raise (Stream.Error "unknown token when expecting an expression.") - -(* unary - * ::= primary - * ::= '!' unary *) -and parse_unary = parser - (* If this is a unary operator, read it. *) - | [< 'Token.Kwd op when op != '(' && op != ')'; operand=parse_expr >] -> - Ast.Unary (op, operand) - - (* If the current token is not an operator, it must be a primary expr. *) - | [< stream >] -> parse_primary stream - -(* binoprhs - * ::= ('+' primary)* *) -and parse_bin_rhs expr_prec lhs stream = - match Stream.peek stream with - (* If this is a binop, find its precedence. *) - | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c -> - let token_prec = precedence c in - - (* If this is a binop that binds at least as tightly as the current binop, - * consume it, otherwise we are done. *) - if token_prec < expr_prec then lhs else begin - (* Eat the binop. *) - Stream.junk stream; - - (* Parse the unary expression after the binary operator. *) - let rhs = parse_unary stream in - - (* Okay, we know this is a binop. *) - let rhs = - match Stream.peek stream with - | Some (Token.Kwd c2) -> - (* If BinOp binds less tightly with rhs than the operator after - * rhs, let the pending operator take rhs as its lhs. *) - let next_prec = precedence c2 in - if token_prec < next_prec - then parse_bin_rhs (token_prec + 1) rhs stream - else rhs - | _ -> rhs - in - - (* Merge lhs/rhs. *) - let lhs = Ast.Binary (c, lhs, rhs) in - parse_bin_rhs expr_prec lhs stream - end - | _ -> lhs - -(* expression - * ::= primary binoprhs *) -and parse_expr = parser - | [< lhs=parse_unary; stream >] -> parse_bin_rhs 0 lhs stream - -(* prototype - * ::= id '(' id* ')' - * ::= binary LETTER number? (id, id) - * ::= unary LETTER number? (id) *) -let parse_prototype = - let rec parse_args accumulator = parser - | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e - | [< >] -> accumulator - in - let parse_operator = parser - | [< 'Token.Unary >] -> "unary", 1 - | [< 'Token.Binary >] -> "binary", 2 - in - let parse_binary_precedence = parser - | [< 'Token.Number n >] -> int_of_float n - | [< >] -> 30 - in - parser - | [< 'Token.Ident id; - 'Token.Kwd '(' ?? "expected '(' in prototype"; - args=parse_args []; - 'Token.Kwd ')' ?? "expected ')' in prototype" >] -> - (* success. *) - Ast.Prototype (id, Array.of_list (List.rev args)) - | [< (prefix, kind)=parse_operator; - 'Token.Kwd op ?? "expected an operator"; - (* Read the precedence if present. *) - binary_precedence=parse_binary_precedence; - 'Token.Kwd '(' ?? "expected '(' in prototype"; - args=parse_args []; - 'Token.Kwd ')' ?? "expected ')' in prototype" >] -> - let name = prefix ^ (String.make 1 op) in - let args = Array.of_list (List.rev args) in - - (* Verify right number of arguments for operator. *) - if Array.length args != kind - then raise (Stream.Error "invalid number of operands for operator") - else - if kind == 1 then - Ast.Prototype (name, args) - else - Ast.BinOpPrototype (name, args, binary_precedence) - | [< >] -> - raise (Stream.Error "expected function name in prototype") - -(* definition ::= 'def' prototype expression *) -let parse_definition = parser - | [< 'Token.Def; p=parse_prototype; e=parse_expr >] -> - Ast.Function (p, e) - -(* toplevelexpr ::= expression *) -let parse_toplevel = parser - | [< e=parse_expr >] -> - (* Make an anonymous proto. *) - Ast.Function (Ast.Prototype ("", [||]), e) - -(* external ::= 'extern' prototype *) -let parse_extern = parser - | [< 'Token.Extern; e=parse_prototype >] -> e |
