=============================
Literal words
=============================

echo a
echo a b

---

(program
  (command (command_name (word)) (word))
  (command (command_name (word)) (word) (word)))

=============================
Words with special characters
=============================

echo {o[k]}
echo }}}
echo ]]] ===

---

(program
  (command (command_name (word)) (concatenation (word) (word)))
  (command (command_name (word)) (word))
  (command (command_name (word)) (word) (word)))

=============================
Simple variable expansions
=============================

echo $abc

---

(program
  (command (command_name (word)) (simple_expansion (variable_name))))

=============================
Special variable expansions
=============================

echo $# $* $@

---

(program
  (command
    (command_name (word))
    (simple_expansion (special_variable_name))
    (simple_expansion (special_variable_name))
    (simple_expansion (special_variable_name))))

=============================
Variable expansions
=============================

echo ${var1#*#}
echo ${!abc}
echo ${abc}
echo ${abc:-def}
echo ${abc:- }
echo ${abc:
}

---

(program
  (command (command_name (word)) (expansion (variable_name) (word)))
  (command (command_name (word)) (expansion (variable_name)))
  (command (command_name (word)) (expansion (variable_name)))
  (command (command_name (word)) (expansion (variable_name) (word)))
  (command (command_name (word)) (expansion (variable_name)))
  (command (command_name (word)) (expansion (variable_name))))

===================================
Variable expansions with operators
===================================

A="${B[0]# }"
C="${D/#* -E /}"
F="${G%% *}"

---

(program
  (variable_assignment
    (variable_name)
    (string (expansion (subscript (variable_name) (word)))))
  (variable_assignment
    (variable_name)
    (string (expansion (variable_name) (regex))))
  (variable_assignment
    (variable_name)
    (string (expansion (variable_name) (word) (word)))))

===================================
Variable expansions in strings
===================================

A="${A:-$B/c}"
A="${b=$c/$d}"

---

(program
  (variable_assignment
    (variable_name)
    (string
      (expansion
        (variable_name)
        (concatenation (simple_expansion (variable_name)) (word)))))
  (variable_assignment
    (variable_name)
    (string
      (expansion
        (variable_name)
        (concatenation
          (simple_expansion (variable_name))
          (word)
          (simple_expansion (variable_name)))))))

===================================
Variable expansions with regexes
===================================

A=${B//:;;/$'\n'}

# escaped space
C=${D/;\ *;|}

---

(program
  (variable_assignment (variable_name) (expansion (variable_name) (regex)))
  (comment)
  (variable_assignment (variable_name) (expansion (variable_name) (regex))))

===================================
Other variable expansion operators
===================================

cat ${BAR} ${ABC=def} ${GHI:?jkl}

---

(program
  (command
    (command_name (word))
    (expansion (variable_name))
    (expansion (variable_name) (word))
    (expansion (variable_name) (word))))

=============================
Command substitutions
=============================

echo `echo hi`
echo `echo hi; echo there`
echo $(echo $(echo hi))

---

(program
  (command
    (command_name (word))
    (command_substitution (command (command_name (word)) (word))))
  (command
    (command_name (word))
    (command_substitution (command (command_name (word)) (word)) (command (command_name (word)) (word))))
  (command
    (command_name (word))
    (command_substitution (command
      (command_name (word))
      (command_substitution (command
        (command_name (word))
        (word)))))))

=============================
Process substitutions
=============================

wc -c <(echo abc && echo def)
wc -c <(echo abc; echo def)
echo abc > >(wc -c)

---

(program
  (command
    (command_name (word))
    (word)
    (process_substitution (list
      (command (command_name (word)) (word))
      (command (command_name (word)) (word)))))
  (command
    (command_name (word))
    (word)
    (process_substitution
      (command (command_name (word)) (word))
      (command (command_name (word)) (word))))
  (redirected_statement
    (command
      (command_name (word))
      (word))
    (file_redirect (process_substitution
      (command (command_name (word)) (word))))))

=============================
Single quoted strings
=============================

echo 'a b' 'c d'

---

(program
  (command (command_name (word)) (raw_string) (raw_string)))

=============================
Double quoted strings
=============================

echo "a" "b"
echo "a ${b} c" "d $e"

---

(program
  (command (command_name (word))
    (string)
    (string))
  (command (command_name (word))
    (string (expansion (variable_name)))
    (string (simple_expansion (variable_name)))))

=========================================
Strings containing command substitutions
=========================================

find "`dirname $file`" -name "$base"'*'

---

(program
  (command
    (command_name (word))
    (string (command_substitution (command (command_name (word)) (simple_expansion (variable_name)))))
    (word)
    (concatenation
      (string (simple_expansion (variable_name)))
      (raw_string))))

=========================================
Strings containing escape sequence
=========================================

echo "\"The great escape\`\${var}"

---

(program (command (command_name (word)) (string)))

======================================
Strings containing special characters
======================================

echo "s/$/'/"
echo "#"
echo "s$"

---

(program
  (command (command_name (word)) (string))
  (command (command_name (word)) (string))
  (command (command_name (word)) (string)))

=========================================
Arrays and array expansions
=========================================

a=()
b=(1 2 3)

echo ${a[@]}
echo ${#b[@]}

a[$i]=50
a+=(foo "bar" $(baz))

---

(program
  (variable_assignment (variable_name) (array))
  (variable_assignment (variable_name) (array (word) (word) (word)))
  (command (command_name (word)) (expansion (subscript (variable_name) (word))))
  (command (command_name (word)) (expansion (subscript (variable_name) (word))))
  (variable_assignment
    (subscript (variable_name) (simple_expansion (variable_name)))
    (word))
  (variable_assignment
    (variable_name)
    (array
      (word)
      (string)
      (command_substitution (command (command_name (word)))))))