Я начинаю играть с Fslex / Fsyacc.При попытке сгенерировать парсер с помощью этого ввода
Parser.fsy:
%{
open Ast
%}
// The start token becomes a parser function in the compiled code:
%start start
// These are the terminal tokens of the grammar along with the types of
// the data carried by each token:
%token <System.Int32> INT
%token <System.String> STRING
%token <System.String> ID
%token PLUS MINUS ASTER SLASH LT LT EQ GTE GT
%token LPAREN RPAREN LCURLY RCURLY LBRACKET RBRACKET COMMA
%token ARRAY IF THEN ELSE WHILE FOR TO DO LET IN END OF BREAK NIL FUNCTION VAR TYPE IMPORT PRIMITIVE
%token EOF
// This is the type of the data produced by a successful reduction of the 'start'
// symbol:
%type <Ast.Program> start
%%
// These are the rules of the grammar along with the F# code of the
// actions executed as rules are reduced. In this case the actions
// produce data using F# data construction terms.
start: Prog { Program($1) }
Prog:
| Expr EOF { $1 }
Expr:
// literals
| NIL { Ast.Nil ($1) }
| INT { Ast.Integer($1) }
| STRING { Ast.Str($1) }
// arrays and records
| ID LBRACKET Expr RBRACKET OF Expr { Ast.Array ($1, $3, $6) }
| ID LCURLY AssignmentList RCURLY { Ast.Record ($1, $3) }
AssignmentList:
| Assignment { [$1] }
| Assignment COMMA AssignmentList {$1 :: $3 }
Assignment:
| ID EQ Expr { Ast.Assignment ($1,$3) }
Ast.fs
namespace Ast
open System
type Integer =
| Integer of Int32
and Str =
| Str of string
and Nil =
| None
and Id =
| Id of string
and Array =
| Array of Id * Expr * Expr
and Record =
| Record of Id * (Assignment list)
and Assignment =
| Assignment of Id * Expr
and Expr =
| Nil
| Integer
| Str
| Array
| Record
and Program =
| Program of Expr
Fsyacc сообщает о следующей ошибке: «FSYACC: ошибка FSY000: элемент с тем же ключом уже добавлен».
Я считаю, что проблема находится в производстве для AssignmentList
, но не могу найтиспособ обойти ...
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