============================================
Identifiers
============================================

foo
foo2
foo.bar
.foo.bar
foo_bar
`a "literal"`
`another
literal \` foo`
_foo


----

(program
 (identifier)
 (identifier)
 (identifier)
 (identifier)
 (identifier)
 (identifier)
 (identifier (escape_sequence))
 (ERROR (placeholder)) (identifier))

============================================
Unicode Identifiers
============================================

你好
.你.好.
.你_好.

----

(program
  (identifier)
  (identifier)
  (identifier))

============================================
Strings
============================================

"foo"
"foo\"bar"
'foo'
'foo\'bar'
"#"
'#'

----

(program
 (string)
 (string (escape_sequence))
 (string)
 (string (escape_sequence))
 (string)
 (string))

============================================
Raw Strings
============================================
r"(raw string)"
R"{another raw string}"
R"--[yet another ]- raw string]--"
r"not a raw string"
r"-(an unclosed raw string"

----

(program
  (string)
  (string)
  (string)
  (identifier) (string)
  (identifier) (string))

============================================
Comments
============================================

# a comment' 

'# not a comment'


'
# still not a comment'

---

(program
 (comment)
 (string)
 (string))

========
Constants
========

TRUE
FALSE
NULL
Inf
NaN
NA
NA_real_
NA_character_
NA_complex_

---

(program
  (true)
  (false)
  (null)
  (inf)
  (nan)
  (na)
  (na)
  (na)
  (na))

========
Integers
========

12332L
0L
12L
0xDEADL

---

(program
  (integer)
  (integer)
  (integer)
  (integer))

======
Floats
======

.66
.11
123.4123
.1234
0xDEAD
x <- -.66

---

(program
  (float)
  (float)
  (float)
  (float)
  (float)

(left_assignment (identifier) (unary (float))))

=====================================
Scientific Notation Floats
=====================================

1e322
1e-3
1e+3
1.8e10
1.e10
1e10

---

(program
  (float)
  (float)
  (float)
  (float)
  (float)
  (float))