The "Unknown:"s below indicate that an entry is incomplete.

• either the entry exist in the language, and please tell.
• either the entry doesn't exist in the language, and please tell so. The entry will be marked as such and won't appear as missing anymore.

• Category: Dynamically typed

• Various

  { ... }	block (grouping statements, especially when statements are not expressions)
  ( ... )(1)	block (grouping statements, especially when statements are not expressions)
  \	breaking lines (useful when end-of-line and/or indentation has a special meaning)
  #	commenting (until end of line)
  -lt -gt -le -ge	comparison
  = !=	equality / inequality (shallow)
  eval	runtime evaluation
  case-sensitive	tokens (case-sensitivity (keywords, variable identifiers...))
  [_a-zA-Z0-9]+	tokens (variable identifier regexp)
  UPPER_CASE	tokens (what is the standard way for scrunching together multiple words)
  =	variable assignment or declaration (assignment)

  Unknown:

  documentation comment
  information about the current line and file
  grouping expressions
  comparison (returns 3 values (i.e. inferior, equal or superior))
  comparison (min / max (binary or more))
  force garbage collection

• Functions

  f a b ...	function call
  f	function call (with no parameter)
  f() { ... }	function definition
  f() { ... $@ }	function definition (variable number of arguments)
  return(2)	function return value (breaks the control flow)

  Unknown:

  function called when a function is not defined (in dynamic languages)
  runtime inspecting the caller information

• Control Flow

  return(2)	breaking control flow (returning a value)
  if c; then ... fi	if_then
  if c; then b1; elif c2; then b2; else b3; fi	if_then_else
  for ((x = 0; x < 10; x++)); do ...; done	loop (for "a la C" (while + initialisation))
  for i in `seq 10 -1 1`; do ...; done	loop (for each value in a numeric range, 1 decrement)
  while c; do ...; done	loop (while condition do something)
  case val in v1) statement1 ;; v2|v3) statement23 ;; *) statement_else ;; esac	multiple selection (switch)
  ;	sequence
  end-of-line	sequence

  Unknown:

  loop (forever loop)
  loop (do something until condition)
  loop (for each value in a numeric range, 1 increment (see also the entries about ranges))
  loop (for each value in a numeric range, free increment)
  breaking control flow (goto (unconditional jump))
  breaking control flow (continue / break)
  exception (throwing)
  exception (catching)

• Package, Module

  . p	import (everything into current namespace)
  source p	import (everything into current namespace)

  Unknown:

  package scope
  declare

• Strings

  "z"	character "z"
  all strings allow multi-line strings	multi-line
  echo(3)	simple print (on strings)
  $a$b	string concatenation
  = !=	string equality & inequality
  ${#v}	string size
  "... $v ..."	strings (with interpolation of variables)
  <<MARK ... $v ... MARK	strings (with interpolation of variables)
  '...'	strings (with no interpolation of variables)
  <<'MARK' ... MARK	strings (with no interpolation of variables)

  Unknown:

  strings (end-of-line (without writing the real CR or LF character))
  serialize (marshalling)
  unserialize (un-marshalling)
  sprintf-like
  duplicate n times
  upper / lower case character
  uppercase / lowercase / capitalized string
  ascii to character
  character to ascii
  accessing n-th character
  extract a substring
  locate a substring
  locate a substring (starting at the end)

• Booleans

  false	false value
  exit status different from 0	false value
  true	true value
  exit status 0	true value

  Unknown:

  logical not
  logical or / and

• Bags and Lists

  for v in l; do ...; done	for each element do something
  a[i]	list/array indexing

• Various Data Types

  seq a b / jot - a b(4)

  range (inclusive .. inclusive)

  Unknown:

  tuple constructor
  computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (empty tuple)
  computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (1-uple)
  computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (using a tuple for a function call)
  reference (pointer) (creation)
  reference (pointer) (dereference)
  optional value (null value)
  optional value (value)
  optional value (null coalescing)
  record (selector)
  dictionary (constructor)
  dictionary (access)
  dictionary (has the key ?)
  dictionary (remove by key)
  dictionary (list of keys)
  dictionary (list of values)
  dictionary (merge)

• Mathematics

  + / - / * / /	addition / subtraction / multiplication / division
  -	negation
  1000	numbers syntax (integers)
  mathematical	operator priorities and associativities (addition vs multiplication)

  Unknown:

  numbers syntax (integers in base 2, octal and hexadecimal)
  exponentiation (power)
  random (random number)
  random (seed the pseudo random generator)
  square root / e-exponential / absolute value
  trigonometry (basic)
  trigonometry (inverse)
  logarithm (base e)
  logarithm (base 10)
  modulo
  truncate / round / floor / ceil
  bitwise operators

Remarks

• (1) introduce scope
• (2) in Lua, "return xxx" can only appear before a block end. in Matlab, only in inline('...')
• (3) in BourneShell, adding an end-of-line
• (4) jot on BSD