metadata = [ `(` commasep( ident [ `:` single\_value ] ) `)` ]
-scalar = integer\_constant | float\_constant
+scalar = boolean\_constant | integer\_constant | float\_constant
-object = { commasep( ident `:` value ) }
+object = `{` commasep( ident `:` value ) `}`
single\_value = scalar | string\_constant
special\_float\_constant = `[-+]?(nan|inf|infinity)`
-float\_constant = decimal\_float\_constant | hexadecimal\_float\_constant | special\_float\_constant
+float\_constant = dec\_integer\_constant | hex\_integer\_constant | special\_float\_constant
-boolean\_constant = `(true|false)` | (integer\_constant ? `true` : `false`)
+boolean\_constant = `true` | `false`