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.

• Various

  { ... }(1)	block (grouping statements, especially when statements are not expressions)
  nothing needed	breaking lines (useful when end-of-line and/or indentation has a special meaning)
  /* ... */	commenting (non nestable)
  < > <= >=	comparison
  == !=	equality / inequality (shallow)
  ( ... )	grouping expressions
  case-sensitive	tokens (case-sensitivity (keywords, variable identifiers...))
  [_a-zA-Z][_a-zA-Z0-9]*	tokens (variable identifier regexp)
  =	variable assignment or declaration (assignment)
  auto v1, v2; extrn v3, v4;	variable assignment or declaration (declaration)

• Functions

  f(a,b,...)	function call
  return(2)	function return value (breaks the control flow)

• Control Flow

  goto	breaking control flow (goto (unconditional jump))
  return(2)	breaking control flow (returning a value)
  if (c) ...	if_then
  if (c) b1 else b2	if_then_else
  c ? b1 : b2	if_then_else
  while (c) ...	loop (while condition do something)
  switch val { case v1: ...; goto done; case v2: case v3: ...; goto done; } ...; done:	multiple selection (switch)
  ;	sequence

• Strings

  char(s, i)	accessing n-th character
  'z'	character "z"
  "*n"	strings (end-of-line (without writing the real CR or LF character))

• Booleans

  0(3)	false value
  !	logical not
  | / &	logical or / and (short circuit)
  anything not false	true value

• Bags and Lists

  a[i]	list/array indexing

• Various Data Types

  &	reference (pointer) (creation)
  *(4)	reference (pointer) (dereference)

• Mathematics

  %	modulo (modulo of -3 / 2 is -1)
  -	negation
  07	numbers syntax (integers in base 2, octal and hexadecimal)
  1000	numbers syntax (integers)

Remarks

• (1) introduce scope
• (2) in Lua, "return xxx" can only appear before a block end. in Matlab, only in inline('...')
• (3) beware of 0.0 which is true in Pike!
• (4) prefix