sxp(x) is similar to .Internal(inspect(x)), recursing into the C data
structures underlying any R object. The main difference is the output is a
little more compact, it recurses fully, and avoids getting stuck in infinite
loops by using a depth-first search. It also returns a list that you can
compute with, and carefully uses colour to highlight the most important
details.
Usage
sxp(x, expand = character(), max_depth = 5L)Arguments
- x
Object to inspect
- expand
Optionally, expand components of the true that are usually suppressed. Use:
"character" to show underlying entries in the global string pool.
"environment" to show the underlying hashtables.
"altrep" to show the underlying data.
"call" to show the full AST (but
ast()is usually superior)"bytecode" to show generated bytecode.
- max_depth
Maximum depth to recurse. Use
max_depth = Inf(with care!) to recurse as deeply as possible. Skipped elements will be shown as....`
Details
The name sxp comes from SEXP, the name of the C data structure that
underlies all R objects.
Examples
x <- list(
TRUE,
1L,
runif(100),
"3"
)
sxp(x)
#> [1:0x561b6cbba428] <VECSXP[4]> (refs:2+)
#> [2:0x561b6abc37c8] <LGLSXP[1]> (refs:2+)
#> [3:0x561b6abc3608] <INTSXP[1]> (refs:2+)
#> [4:0x561b69da2af0] <REALSXP[100]> (refs:1)
#> [5:0x561b6abc2fb0] <STRSXP[1]> (refs:2+)
# Expand "character" to see underlying CHARSXP entries in the global
# string pool
x <- c("banana", "banana", "apple", "banana")
sxp(x)
#> [1:0x561b6a53b8a8] <STRSXP[4]> (refs:2+)
sxp(x, expand = "character")
#> [1:0x561b6a53b8a8] <STRSXP[4]> (refs:2+)
#> [2:0x561b6a4a0540] <CHARSXP> (refs:2+)
#> [2:0x561b6a4a0540]
#> [3:0x561b670af300] <CHARSXP> (refs:2+)
#> [2:0x561b6a4a0540]
# Expand altrep to see underlying data
x <- 1:10
sxp(x)
#> [1:0x561b6ae59408] <INTSXP[10]> (altrep refs:2+)
sxp(x, expand = "altrep")
#> [1:0x561b6ae59408] <INTSXP[10]> (altrep refs:2+)
#> _class [2:0x561b63da2c20] <RAWSXP[144]> (refs:2+)
#> _attrib [3:0x561b63dd8638] <LISTSXP> (refs:1)
#> [4:0x561b63dd8868] <SYMSXP: compact_intseq> (refs:2+)
#> [5:0x561b63da42c0] <SYMSXP: base> (refs:2+)
#> [6:0x561b63dd7128] <INTSXP[1]> (refs:2+)
#> _data1 [7:0x561b692bd668] <REALSXP[3]> (refs:1)
#> _data2 <NILSXP>
# Expand environmnets to see the underlying implementation details
e1 <- new.env(hash = FALSE, parent = emptyenv(), size = 3L)
e2 <- new.env(hash = TRUE, parent = emptyenv(), size = 3L)
e1$x <- e2$x <- 1:10
sxp(e1)
#> [1:0x561b6b0c0fa0] <ENVSXP> (refs:2+)
#> x [2:0x561b6b11a020] <INTSXP[10]> (altrep refs:2+)
#> _enclos [3:0x561b63da55c8] <ENVSXP: empty> (refs:2+)
sxp(e1, expand = "environment")
#> [1:0x561b6b0c0fa0] <ENVSXP> (refs:2+)
#> _frame [2:0x561b6b119a00] <LISTSXP> (refs:1)
#> x [3:0x561b6b11a020] <INTSXP[10]> (altrep refs:2+)
#> _hashtab <NILSXP>
#> _enclos [5:0x561b63da55c8] <ENVSXP: empty> (refs:2+)
sxp(e2, expand = "environment")
#> [1:0x561b6b0ec918] <ENVSXP> (refs:2+)
#> _frame <NILSXP>
#> _hashtab [3:0x561b6a1cbae8] <VECSXP[3]> (refs:1)
#> [4:0x561b6b119d10] <LISTSXP> (refs:1)
#> x [5:0x561b6b11a020] <INTSXP[10]> (altrep refs:2+)
#> <NILSXP>
#> <NILSXP>
#> _enclos [6:0x561b63da55c8] <ENVSXP: empty> (refs:2+)