1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
#!/usr/bin/env Rscript
### Example R script for syntax highlighting
# This is also a comment
## Valid names
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUV0123456789._a <- NULL
f2_bar <- NULL
F2_BAR <- NULL
.foo_ <- NULL
._foo <- NULL
. <- NULL
.. <- NULL
... <- NULL
c <- NULL
c(T, F)
## Invalid names
0abc <- NULL
.0abc <- NULL
abc+cde <- NULL
_ <- NULL
_x <- NULL
## Reserved Words
NA
NA_integer_
NA_real_
NA_character_
NA_complex_
NULL
NaN
Inf
## Not reserved
NULLa <- NULL
NULL1 <- NULL
NULL. <- NULL
NA_foo_ <- NULL
## Numbers
12345678901
123456.78901
123e3
123E3
1.23e-3
1.23e3
1.23e-3
.25
## integer constants
123L
1.23L
## imaginary numbers
123i
-123i
123e4i
123e-4i
## Hex numbers
0xabcdefABCDEF01234
0xabcp123
0xabcP123
## Not hex
0xg
## Special operators %xyz%
## %xyz%
1 %% 2
diag(2) %*% diag(2)
1 %/% 2
1 %in% 1:10
diag(2) %o% diag(2)
diag(2) %x% diag(2)
`%foo bar%` <- function(x, y) x + y
1 %foo bar% 2
## Control Structures (3.2) and Function
## if, else
if (TRUE) print("foo") else print("bar")
## For, in
for(i in 1:5) {
print(i)
}
## While, break
i <- 1
while (TRUE) {
i <- i + 1
if (i > 3) break
}
## Repeat
repeat {1+1}
## Switch
x <- 3
switch(x, 2+2, mean(1:10), rnorm(5))
## Function, dot-dot-dot, return
foo <- function(...) {
return(sum(...))
}
# Not keywords
functiona <- 2 + 2
function. <- 2 + 2
function1 <- 2 + 2
## Grouping Tokens 10.3.7
## Parentheses
1 + (2 + 3)
## brackets
foo <- function(a) {
a + 1
}
## Indexing 10.3.8
## []
bar <- 1:10
bar[3]
## [[]]
foo <- list(a=1, b=2, c=3)
foo[["a"]]
## $
foo$a
foo$"a"
## Operators
2 - 2
2 + 2
2 ~ 2
! TRUE
?"help"
1:2
2 * 2
2 / 2
2^2
2 < 2
2 > 2
2 == 2
2 >= 2
2 <= 2
2 != 2
TRUE & FALSE
TRUE && FALSE
TRUE | FALSE
TRUE || FALSE
foo <- 2 + 2
foo = 2 + 2
2 + 2 -> foo
foo <<- 2 + 2
2 + 2 ->> foo
base:::sum
base::sum
## Strings
foo <- "hello, world!"
foo <- 'hello, world!'
foo <- "Hello, 'world!"
foo <- 'Hello, "world!'
foo <- 'Hello, \'world!\''
foo <- "Hello, \"world!\""
foo <- "Hello,
world!"
foo <- 'Hello,
world!'
## Backtick strings
`foo123 +!"bar'baz` <- 2 + 2
x = ` ` % % 2
## Builtin names
LETTERS
letters
month.abb
month.name
pi
## Roxygen
#' A description
#'
#' Long description
#' @param x the object
#' @return A logical indicating whether \code{x == 0}
is_zero = function (x) x == 0
|
