Parse scalar expressions with source spans

src/parser.mly

@@ -0,0 +1,85 @@
+%{
+open Syntax
+
+let here () = Location.span_of_lexing (Parsing.symbol_start_pos ()) (Parsing.symbol_end_pos ())
+%}
+
+%token <int> INT
+%token <bool> BOOL
+%token <string> STRING
+%token <string> IDENT
+%token LET IN FUN IF THEN ELSE
+%token ARROW PIPE AND OR
+%token EQ NE LT LE GT GE
+%token PLUS MINUS STAR SLASH
+%token LPAREN RPAREN COMMA DOT LBRACE RBRACE COLON SEMI
+%token EOF
+
+%start expr
+%type <Syntax.expr> expr
+
+%%
+
+expr:
+  | pipeline { $1 }
+
+pipeline:
+  | disjunction { $1 }
+  | pipeline PIPE disjunction { make (EApp ($3, $1)) (here ()) }
+
+disjunction:
+  | conjunction { $1 }
+  | disjunction OR conjunction { make (EBinop (Or, $1, $3)) (here ()) }
+
+conjunction:
+  | comparison { $1 }
+  | conjunction AND comparison { make (EBinop (And, $1, $3)) (here ()) }
+
+comparison:
+  | sum { $1 }
+  | sum EQ sum { make (EBinop (Eq, $1, $3)) (here ()) }
+  | sum NE sum { make (EBinop (Ne, $1, $3)) (here ()) }
+  | sum LT sum { make (EBinop (Lt, $1, $3)) (here ()) }
+  | sum LE sum { make (EBinop (Le, $1, $3)) (here ()) }
+  | sum GT sum { make (EBinop (Gt, $1, $3)) (here ()) }
+  | sum GE sum { make (EBinop (Ge, $1, $3)) (here ()) }
+
+sum:
+  | product { $1 }
+  | sum PLUS product { make (EBinop (Add, $1, $3)) (here ()) }
+  | sum MINUS product { make (EBinop (Sub, $1, $3)) (here ()) }
+
+product:
+  | unary { $1 }
+  | product STAR unary { make (EBinop (Mul, $1, $3)) (here ()) }
+  | product SLASH unary { make (EBinop (Div, $1, $3)) (here ()) }
+
+unary:
+  | application { $1 }
+  | MINUS unary { make (ENeg $2) (here ()) }
+
+application:
+  | atom { $1 }
+  | application atom { make (EApp ($1, $2)) (here ()) }
+
+atom:
+  | INT { make (EInt $1) (here ()) }
+  | BOOL { make (EBool $1) (here ()) }
+  | STRING { make (EString $1) (here ()) }
+  | IDENT { make (EVar $1) (here ()) }
+  | LPAREN RPAREN { make EUnit (here ()) }
+  | LPAREN expr RPAREN { $2 }
+  | LPAREN expr COMMA expr_list RPAREN { make (ETuple ($2 :: $4)) (here ()) }
+  | LBRACE record_fields RBRACE { make (ERecord $2) (here ()) }
+  | atom DOT IDENT { make (EField ($1, $3)) (here ()) }
+  | LET IDENT EQ expr IN expr { make (ELet ($2, $4, $6)) (here ()) }
+  | FUN IDENT ARROW expr { make (ELambda ($2, $4)) (here ()) }
+  | IF expr THEN expr ELSE expr { make (EIf ($2, $4, $6)) (here ()) }
+
+expr_list:
+  | expr { [ $1 ] }
+  | expr COMMA expr_list { $1 :: $3 }
+
+record_fields:
+  | IDENT EQ expr { [ ($1, $3) ] }
+  | IDENT EQ expr SEMI record_fields { ($1, $3) :: $5 }