func Eval(expression string) (*Result, error) {
var status C.ParseStatus
cmd := C.CString(expression)
defer C.free(unsafe.Pointer(cmd))
cmdRChar := C.mkChar(cmd)
protector := Protect(cmdRChar)
defer protector.Unprotect()
cmdSexp := C.allocVector(C.STRSXP, 1)
protector.Protect(cmdSexp)
C.SET_STRING_ELT(cmdSexp, 0, cmdRChar)
parsedCmd := C.R_ParseVector(cmdSexp, -1, (*C.ParseStatus)(unsafe.Pointer(&status)), C.R_NilValue)
if status != C.PARSE_OK {
return nil, fmt.Errorf("Invalid command: %s", C.GoString(cmd))
}
protector.Protect(parsedCmd)
var result C.SEXP
errorOccured := 0
/* Loop is needed here as EXPSEXP will be of length > 1 */
for i := 0; i < int(C.Rf_length(parsedCmd)); i++ {
result = C.R_tryEval(C.VECTOR_ELT(parsedCmd, C.R_xlen_t(i)), C.R_GlobalEnv, (*C.int)(unsafe.Pointer(&errorOccured))) //R 3.0
if errorOccured != 0 {
return nil, fmt.Errorf("R error occured executing: %s", C.GoString(cmd))
}
}
return NewResult(result), nil
}
func toIface(s C.SEXP) interface{} {
// generate a go map or slice or scalar value, then encode it
n := int(C.Rf_xlength(s))
if n == 0 {
return nil // drops type info. Meh.
}
switch C.TYPEOF(s) {
case C.VECSXP:
// an R generic vector; e.g list()
VPrintf("encodeRIntoMsgpack sees VECSXP\n")
// could be a map or a slice. Check out the names.
rnames := C.Rf_getAttrib(s, C.R_NamesSymbol)
rnamesLen := int(C.Rf_xlength(rnames))
VPrintf("namesLen = %d\n", rnamesLen)
if rnamesLen > 0 {
myMap := map[string]interface{}{}
for i := 0; i < rnamesLen; i++ {
myMap[C.GoString(C.get_string_elt(rnames, C.int(i)))] = toIface(C.VECTOR_ELT(s, C.R_xlen_t(i)))
}
VPrintf("VECSXP myMap = '%#v'\n", myMap)
return myMap
} else {
// else: no names, so we treat it as an array instead of as a map
mySlice := make([]interface{}, n)
for i := 0; i < n; i++ {
mySlice[i] = toIface(C.VECTOR_ELT(s, C.R_xlen_t(i)))
}
VPrintf("VECSXP mySlice = '%#v'\n", mySlice)
return mySlice
}
case C.REALSXP:
// a vector of float64 (numeric)
VPrintf("encodeRIntoMsgpack sees REALSXP\n")
mySlice := make([]float64, n)
for i := 0; i < n; i++ {
mySlice[i] = float64(C.get_real_elt(s, C.int(i)))
}
VPrintf("VECSXP mySlice = '%#v'\n", mySlice)
return mySlice
case C.INTSXP:
// a vector of int32
VPrintf("encodeRIntoMsgpack sees INTSXP\n")
mySlice := make([]int, n)
for i := 0; i < n; i++ {
mySlice[i] = int(C.get_int_elt(s, C.int(i)))
}
VPrintf("INTSXP mySlice = '%#v'\n", mySlice)
return mySlice
case C.RAWSXP:
VPrintf("encodeRIntoMsgpack sees RAWSXP\n")
mySlice := make([]byte, n)
C.memcpy(unsafe.Pointer(&mySlice[0]), unsafe.Pointer(C.RAW(s)), C.size_t(n))
VPrintf("RAWSXP mySlice = '%#v'\n", mySlice)
return mySlice
case C.STRSXP:
// a vector of string (pointers to charsxp that are interned)
VPrintf("encodeRIntoMsgpack sees STRSXP\n")
mySlice := make([]string, n)
for i := 0; i < n; i++ {
mySlice[i] = C.GoString(C.get_string_elt(s, C.int(i)))
}
VPrintf("STRSXP mySlice = '%#v'\n", mySlice)
return mySlice
case C.NILSXP:
// c(); an empty vector
VPrintf("encodeRIntoMsgpack sees NILSXP\n")
return nil
case C.CHARSXP:
// a single string, interned in a global pool for reuse by STRSXP.
VPrintf("encodeRIntoMsgpack sees CHARSXP\n")
case C.SYMSXP:
VPrintf("encodeRIntoMsgpack sees SYMSXP\n")
case C.LISTSXP:
VPrintf("encodeRIntoMsgpack sees LISTSXP\n")
case C.CLOSXP:
VPrintf("encodeRIntoMsgpack sees CLOSXP\n")
case C.ENVSXP:
VPrintf("encodeRIntoMsgpack sees ENVSXP\n")
case C.PROMSXP:
VPrintf("encodeRIntoMsgpack sees PROMSXP\n")
case C.LANGSXP:
VPrintf("encodeRIntoMsgpack sees LANGSXP\n")
case C.SPECIALSXP:
VPrintf("encodeRIntoMsgpack sees SPECIALSXP\n")
case C.BUILTINSXP:
VPrintf("encodeRIntoMsgpack sees BUILTINSXP\n")
case C.LGLSXP:
VPrintf("encodeRIntoMsgpack sees LGLSXP\n")
case C.CPLXSXP:
VPrintf("encodeRIntoMsgpack sees CPLXSXP\n")
case C.DOTSXP:
VPrintf("encodeRIntoMsgpack sees DOTSXP\n")
case C.ANYSXP:
VPrintf("encodeRIntoMsgpack sees ANYSXP\n")
case C.EXPRSXP:
VPrintf("encodeRIntoMsgpack sees EXPRSXP\n")
case C.BCODESXP:
VPrintf("encodeRIntoMsgpack sees BCODESXP\n")
case C.EXTPTRSXP:
VPrintf("encodeRIntoMsgpack sees EXTPTRSXP\n")
case C.WEAKREFSXP:
VPrintf("encodeRIntoMsgpack sees WEAKREFSXP\n")
case C.S4SXP:
VPrintf("encodeRIntoMsgpack sees S4SXP\n")
default:
VPrintf("encodeRIntoMsgpack sees <unknown>\n")
}
VPrintf("... warning: encodeRIntoMsgpack() ignoring this input.\n")
return nil
}