26 lines
533 B
FSharp
26 lines
533 B
FSharp
%{
|
|
open AbstractSyntaxTree
|
|
%}
|
|
|
|
%start Expr
|
|
|
|
// terminal tokens
|
|
%token <int> INT
|
|
%token PLUS MINUS TIMES DIVIDE LPAREN RPAREN
|
|
%token EOF
|
|
|
|
// associativity and precedences
|
|
%left PLUS MINUS
|
|
%left TIMES DIVIDE
|
|
|
|
// return type of Expr
|
|
%type <Expression> Expr
|
|
|
|
%%
|
|
|
|
Expr: INT { Int $1 }
|
|
| Expr PLUS Expr { Plus ($1, $3) }
|
|
| Expr MINUS Expr { Minus ($1, $3) }
|
|
| Expr TIMES Expr { Times ($1, $3) }
|
|
| Expr DIVIDE Expr { Divide ($1, $3) }
|
|
| LPAREN Expr RPAREN { $2 }
|