============================================
Functions
============================================
function() 1
function() {}
function(arg1, arg2) {
  arg2
}

function(x, y) return(y)

function(x, ...) f(...)

function(arg1, arg2 = 2) {}

----

(program
  (function_definition (formal_parameters) (float))
  (function_definition (formal_parameters) (brace_list))
  (function_definition
    (formal_parameters (identifier) (identifier))
    (brace_list (identifier)))
  (function_definition
    (formal_parameters (identifier) (identifier))
    (call
     function: (identifier)
     arguments: (arguments (identifier))))
  (function_definition
    (formal_parameters (identifier) (dots))
    (call 
      function: (identifier)
      arguments: (arguments
        (dots))))
  (function_definition
    (formal_parameters
      (identifier)
      (default_parameter
        name: (identifier)
        value: (float)))
    (brace_list)))

=======================
Lambda Function
=======================

a <- \(arg) arg
b <- \(arg1, arg2) paste0(arg1, arg2)
c <- \(fun, ...) fun(...)
1:3 |> {\(x, y = 1) x + y}() |> {\(x) sum(x)}()
{\(a = 1) a + 1}()
\() 1 + 2
---
(program

  (left_assignment
    name: (identifier)
    value: (lambda_function
      (formal_parameters (identifier))
      (identifier)))

  (left_assignment
    name: (identifier)
    value: (lambda_function
      (formal_parameters
        (identifier)
        (identifier))
      (call
        function: (identifier)
        arguments: (arguments
          (identifier)
          (identifier)))))

  (left_assignment
   name: (identifier)
   value: (lambda_function
     (formal_parameters
       (identifier)
       (dots))
     (call
       function: (identifier)
       arguments: (arguments (dots)))))

  (pipe
    left: (pipe
      left: (binary
        left: (float)
        right: (float))
      right: (call
        function: (brace_list
          (lambda_function
            (formal_parameters
              (identifier)
              (default_parameter
                name: (identifier)
                value: (float)))
            (binary
             left: (identifier)
             right: (identifier))))))
    right: (call
      function: (brace_list
        (lambda_function
         (formal_parameters
          (identifier))
         (call
           function: (identifier)
           arguments: (arguments
             (identifier)))))))

    (call
      function: (brace_list
        (lambda_function
         (formal_parameters
          (default_parameter
            name: (identifier)
            value: (float)))
         (binary
          left: (identifier)
          right: (float)))))

    (lambda_function
     (formal_parameters)
     (binary
      left: (float)
      right: (float))))

==========
Relational
==========

a == b

---
(program
  (binary
    left: (identifier) right: (identifier)))

========
Additive
========

a + b

---

(program
  (binary
    left: (identifier) right: (identifier)))

========
Multiplicative
========

a * b

---

(program
  (binary
    left: (identifier) right: (identifier)))

==============
Binary operations
==============

2+2*2

---

(program
  (binary
    left: (float)
    right: (binary
      left: (float)
      right: (float))))

===========
Unary minus
===========

-a
foo(-a, bar)

---

(program
  (unary operand: (identifier))
  (call
    function: (identifier)
    arguments: (arguments
      (unary operand: (identifier))
      (identifier))))

===========
Binary minus
===========

foo-a

---

(program
  (binary left: (identifier) right: (identifier)))


===================
Operator precedence
===================

a <= b && c >= d
a[1] <- foo || bar
a && b(c) && d
val <- foo %>% bar(1) %>% baz()

---

(program

  (binary
    left: (binary left: (identifier) right: (identifier))
    right: (binary left: (identifier) right: (identifier)))

  (left_assignment
    name: (subset (identifier) (arguments (float)))
    value: (binary left: (identifier) right: (identifier)))

  (binary
    left: (binary
      left: (identifier)
      right: (call
        function: (identifier)
        arguments: (arguments
          (identifier))))
    right: (identifier))

  (left_assignment
    name: (identifier)
    value: (binary
      left: (binary
        left: (identifier)
        operator: (special)
        right: (call
          function: (identifier)
          arguments: (arguments
            (float))))
      operator: (special)
      right: (call
        function: (identifier)))))

========
Specials
========

x %% y

x %+% y

x %>% y

x %some text% y

x %some \% escaped text% y

---

(program
  (binary left: (identifier) operator: (special) right: (identifier))
  (binary left: (identifier) operator: (special) right: (identifier))
  (binary left: (identifier) operator: (special) right: (identifier))
  (binary left: (identifier) operator: (special) right: (identifier))
  (binary left: (identifier) operator: (special (escape_sequence)) right: (identifier)))

========
Pipe
========

x |> print()

x |> foo() |> bar() + baz()

x |> {function(x) x}()

---

(program

  (pipe
    left: (identifier)
    right: (call
      function: (identifier)))

  (binary
    left: (pipe
      left: (pipe
        left: (identifier)
        right: (call
          function: (identifier)))
      right: (call
        function: (identifier)))
    right: (call
      function: (identifier)))

  (pipe
    left: (identifier)
    right: (call
      function: (brace_list
        (function_definition
          (formal_parameters
           (identifier))
          (identifier))))))

===========
Pipe Placeholder
===========

foo |> bar(x, y = _)
foo |> bar() |> baz(data = _)

---

(program
  (pipe
    left: (identifier)
    right: (call
      function: (identifier)
      arguments: (arguments
        (identifier)
        (default_argument
          name: (identifier)
          value: (placeholder)))))
  (pipe
    left: (pipe
      left: (identifier)
      right: (call
        function: (identifier)))
    right: (call
      function: (identifier)
      arguments: (arguments
        (default_argument
          name: (identifier)
          value: (placeholder))))))

===========
Subset
===========

foo[bar]
foo[1, 2]
foo[1, ]
foo[]

---

(program
  (subset
    (identifier)
    (arguments
     (identifier)))
  (subset
    (identifier)
    (arguments
      (float)
      (float)))
  (subset
    (identifier)
    (arguments
      (float)))
  (subset
    (identifier)))

===========
Subset2
===========

foo[[x]]
foo[[x, y]]
foo[[]]

---

(program
  (subset2 (identifier)
  (arguments (identifier)))

  (subset2 (identifier)
  (arguments (identifier) (identifier)))

  (subset2
    (identifier)))

============================================
If
============================================

if (x)
  log(y)

if (a.b) {
  log(c)
  d
}

---

(program
  (if
    condition: (identifier)
    consequence: (call function: (identifier) arguments: (arguments (identifier))))
  (if
    condition: (identifier)
    consequence: (brace_list
      (call
       function: (identifier)
       arguments: (arguments (identifier)))
      (identifier))))

============================================
If-else
============================================

if (x)
  y else if (a)
  b

if (a) {
  c
  d
} else {
  e
}

---

(program
  (if
   condition: (identifier)
   consequence: (identifier)
   alternative: (if
     condition: (identifier)
     consequence: (identifier)))

  (if
   condition: (identifier)
   consequence: (brace_list (identifier) (identifier))
   alternative: (brace_list (identifier))))


===
for
===

for (x in y)
  f

---

(program
  (for
    name: (identifier)
    vector: (identifier)
    body: (identifier)))

=====
While
=====
while(TRUE)
  bar

while(x > 0)
  x <- x - 1

while(TRUE)
  break

while(TRUE)
  next

---

(program
  (while
    condition: (true)
    body: (identifier))

  (while
    condition: (binary
      left: (identifier)
      right: (float))
    body: (left_assignment
      name: (identifier)
      value: (binary
        left: (identifier)
        right: (float))))

  (while
    condition: (true)
    body: (break))

  (while
    condition: (true)
    body: (next)))

=====
Repeat
=====

repeat 1

---

(program
  (repeat
    body: (float)))

======
Switch
======

switch(foo,
  x = 1,
  "y" = 2,
  z = ,
  3
)

---

(program
  (switch
   value: (identifier)
   body: (arguments
    (default_argument
      name: (identifier)
      value: (float))
    (default_argument
      name: (string)
      value: (float))
    (default_argument
      name: (identifier))
    (float))))

======
Dollar
======

foo$bar

foo$"bar"

---

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

======
Slot
======

foo@bar

---

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

============================================
Namespace get
============================================

foo::bar
foo::bar(1)

---

(program
  (namespace_get
    namespace: (identifier)
    function: (identifier))
  (call
    function: (namespace_get
     namespace: (identifier)
     function: (identifier))
    arguments: (arguments (float))))

============================================
Namespace get internal
============================================

foo:::bar
foo:::bar(1)

---

(program
  (namespace_get_internal
    namespace: (identifier)
    function: (identifier))
  (call
    function: (namespace_get_internal
     namespace: (identifier)
     function: (identifier))
    arguments: (arguments (float))))

==========
Assignment
==========

x <- 1
x = 1
x := 1
x <<- 1
1 ->> x
1 -> x
x <- y(1)
y(1) -> x

---

(program
  (left_assignment
    name: (identifier)
    value: (float))

  (equals_assignment
    name: (identifier)
    value: (float))

  (left_assignment2
    name: (identifier)
    value: (float))

  (super_assignment
   name: (identifier)
   value: (float))

  (super_right_assignment
   value: (float)
   name: (identifier))

  (right_assignment
   value: (float)
   name: (identifier))

  (left_assignment
   name: (identifier)
   value: (call function: (identifier) arguments: (arguments (float))))

  (right_assignment
   value: (call function: (identifier) arguments: (arguments (float)))
   name: (identifier)))

=====
Calls
=====

f()
f(x)
f(1+1)
f(1 ~ 1)
f(x, )
f(x, y)
f(x, y = 2)
f(x = 1 + 1)
f(x, y =)
f(f2(x, y))
f(,)
f(x,)
f(,y)
f(x=,)
f("x"=,)
f(... = ,)
f(,y=)

---

(program

  (call function: (identifier))

  (call
    function: (identifier)
    arguments: (arguments (identifier)))

  (call
   function: (identifier)
   arguments: (arguments
     (binary
       left: (float)
       right: (float))))

  (call
   function: (identifier)
   arguments: (arguments
     (binary
       left: (float)
       right: (float))))

  (call
    function: (identifier)
    arguments: (arguments (identifier)))

  (call
    function: (identifier)
    arguments: (arguments (identifier) (identifier)))

  (call
    function: (identifier)
    arguments: (arguments 
      (identifier)
      (default_argument
        name: (identifier)
        value: (float))))

  (call
    function: (identifier)
    arguments: (arguments
      (default_argument
        name: (identifier)
        value: (binary left: (float) right: (float)))))

  (call
    function: (identifier)
    arguments: (arguments 
      (identifier)
      (default_argument
        name: (identifier))))

  (call
    function: (identifier)
    arguments: (arguments
      (call
       function: (identifier)
       arguments: (arguments (identifier) (identifier)))))

  (call
    function: (identifier)
    arguments: (arguments))

  (call
    function: (identifier)
    arguments: (arguments (identifier)))

  (call
    function: (identifier)
    arguments: (arguments (identifier)))

  (call
    function: (identifier)
    arguments: (arguments
      (default_argument
        name: (identifier))))

  (call
    function: (identifier)
    arguments: (arguments
      (default_argument
        name: (string))))

  (call
    function: (identifier)
    arguments: (arguments
      (default_argument
        name: (dots))))

  (call
    function: (identifier)
    arguments: (arguments
      (default_argument
        name: (identifier)))))

======
Braces
======

{}

{1}

{1; 2}

{1;
2}

{1
2
}

{
1
2
}

---

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

=====
Colon
=====

1:2
(1 + 1):-5

---

(program
  (binary left: (float) right: (float))

  (binary
    left: (paren_list
      (binary
        left: (float)
        right: (float)))
    right: (unary
      operand: (float))))

=====
Formulas
=====

~x
y~x

---

(program

  (unary operand: (identifier))

  (binary left: (identifier) right: (identifier)))

============================================
Help Operator
============================================
a ? b
a ? b <- 1

---

(program
  (help
    (identifier)
    (identifier))
  (help
    (identifier)
    (left_assignment
      (identifier)
      (float))))

============================================
Complex Expressions
============================================
repeat if (1) TRUE else repeat 42
if (TRUE) if (FALSE) 2 else NULL
a::b$c[[d]] <- e
TRUE ~ FALSE ~ NULL ? NA ? NaN
if (TRUE) FALSE
else NA
(if (TRUE) FALSE
else NA)
a = TRUE ? FALSE
TRUE <- FALSE = NA
TRUE <- FALSE ? NA
TRUE = FALSE ? NA
TRUE ? FALSE = NA

---

(program
  (repeat
    (if
      (float)
      (true)
      (repeat
        (float))))
  (if
    (true)
    (if
      (false)
      (float)
      (null)))
  (left_assignment
    (subset2
      (dollar
        (namespace_get
          (identifier)
          (identifier))
       (identifier))
       (arguments
        (identifier)))
    (identifier))
  (help
    (help
      (binary
        (binary
          (true)
          (false))
        (null))
      (na))
    (nan))
  (if
    (true)
    (false))
  (identifier)
  (na)
  (paren_list
    (if
      (true)
      (false)
      (na)))
  (help
    (equals_assignment
      (identifier)
      (true))
    (false))
  (equals_assignment
    (left_assignment
      (true)
      (false))
    (na))
  (help
    (left_assignment
      (true)
      (false))
    (na))
  (help
    (equals_assignment
      (true)
      (false))
    (na))
  (help
    (true)
    (equals_assignment
      (false)
      (na))))

============================================
Precedence Tests
============================================
A$"B"^NA
a::b$c
a$b?c

----
(program
  (binary
    (dollar
      (identifier)
      (string))
    (na))
  (dollar
    (namespace_get
      (identifier)
      (identifier))
    (identifier))
  (help
    (dollar
      (identifier)
      (identifier))
    (identifier)))