The rules of C++ as encountered so far.


LEXICAL RULES, spaces not allowed
---------------------------------


number

  optional + or -
    then
  any number of digits, including none, A
    then
  optional .
    then
  any number of digits, including none, B, num digits in A and B must be > 0
    then
  optional
  ( e or E
      then
    optional + or -
      then
    any number of digits, but at least one )


string

  "
    then
  any number of characters except ", zero chars is allowed
    then
  "


char

  '
    then
  one character but not '
    then
  '

name

  letter or underline
    then
  any number of letters, digits, and underlines


SYNTACTICAL RULES, spaces allowed
---------------------------------


simple-expression

  number
    or
  string
    or
  true or false
    or
  char
    or
  name


dyadic-op

  + or - or * or % or <= or .....


prefix-op

  + or - or ! or .....


postfix-op

  ++ or -- or ....


type

  int or double or string or ...


param-def

  optional const
    then
  type
    then
  name


param-defs

  param-def
    then
  optional any number of
  ( ,
      then
    param-def )


function-call

  name
    then
  (
    then
  optional
    expression
      then
    any number including zero of
      ,
        then
      expression
    then
  )


expression

  simple-expression
    or
  expression then dyadic-op then expression
    or
  prefix-op then expression
    or
  expression then postfix-op
    or
  expression then ? then expression then : then expression
    or
  function-call
    or
  ( then expression then )


if-statement

  if
    then
  (
    then
  expression
    then
  )
    then
  statement
    then
  optional 
    else 
      then 
    statement


return-statement

  return
    then
  optional expression
    then
  ; 


compound-statement

  {
    any number of, including none
      statement
  }
    

statements

  expression then ;
    or
  if-statement
    or
  return-statement
    or
  compound-statement


const-def

  const
    then
  type
    then
  name
    then
  =
    then
  expression
    then
  ;


func-def

  type
    then
  name
    then
  (
    then
  optional param-defs
    then
  )
    compound-statement


definition

  const-def
    or
  func-def


directive

  #include
    then 
      string
    or
      <
        then
      name
        then
      >

    
program

  any number of, but at least one
    definition
      or
    directive