`string->fp:`procedureConverts the given decimal string number to binary IEEE floating point representation. Optional argument

`ROUNDING`is a symbol that can be one of:`toward-zero`- indicates rounding-towards-zero mode (the default)
`nearest`- indicates rounding-towards-nearest mode
`toward+Inf`- indicates rounding-towards +Inf mode
`toward-Inf`- indicates rounding-towards -Inf mode