C02/doc/small-c.txt

Types
  char — 8 bit data element
  int  — 16 bit data element

Declarations
  type name — declares name to be element
  type *name — declares name to be pointer to element of specified type
  type name[] — syntactically identical to above pointer declaration
  type name[constant] — declares an array of "constant” size where 
                        each array element is of specified type
                        
Constants
  Decimal number.
  Single or pair of ASCII characters enclosed in single quotes, 
    such as ‘a’ or ‘T X ’.
  String enclosed in double quotes, such as “this is a string”.
    The value such a constant yields is a pointer to the first character 
    of the string which the compiler stores in memory.
  
Function Calls
  Defined as any expression followed by an open paren. Thus, a function 
  can be to a named routine, such as “print()” , or to the results of some
  expression, such as “1000()” (which calls location 1000 decimal), or
  “array[i]()” which calls the location whose value is found in array[i] .
  
Subscripted elements. 
  Either an array name or a pointer may be subscripted to refer to the 
  appropriate element. Subscripts are assumed to start from zero. Therefore, 
  legal expressions are:
    array [0] - the first element in array,
    array [x+31] — the element at the address given by adding x to 31 
                   and then to array,
    pointer [i] — the elemen t at the address given by adding i to the 
                  contents of pointer.
  Only single dimensions are allowed. Subscripting either an integer array 
  or a pointer to an integer will cause the subscript expression to be 
  doubled. Therefore, if you declare “int *ptr”, the expression “ptr[3]” 
  refers to the element at ptr+6.
  
Unary Expression Operators
  "-"  — forms the two’s complement of the expression (minus).
  “*”  — refers to the element pointed to by the expression
         (providing the expression is a pointer).
  “&”  — evaluates the address of the given expression, providing 
         it hasone. Hence, &count yields the address of the element 
         “count”. &1000 is an error.
  “&”  — increments the expression by one. If this appears before the 
         expression, it increments before using it. If it appears after 
         it, it will increment it after.  Only values (expressions which 
         can appear on the left-hand side of an equal sign) are allowed.
         Hence, assuming “count” contains a 5, ++count would evaluate to
         a 6, and “count” would contain a 6. Likewise, count++ would 
         evaluate to a 5, and count would contain a 6. 1000++ is illegal.
         If this operator is applied to an integer pointer, it will
         increment by 2.
  "--" — decrements the expression by one. This works just like ++ but 
         subtracts one rather than adding.
  
Binary Operators
  “+” — adds the two expressions (i.e. count + total)
  "-" — subtracts the two expressions.
  “*” — multiplies the two expressions.
  “/” — divides the first expression by the second.
  "%" — yields the remainder after dividing the first expression
        by the second (modulo).
  “|” — yields the logical inclusive “or” of the two expressions.
  "^" — yields the logical exclusive “or” of the two expressions.
  "&" — yields the logical “and”  of the two expressions.
  “=” — assigns the value of the expression on the right to the one 
        on the left. Since evaluation is done right to left in this 
        case, syntaxes like "x = y = z" are legal.
        
Comparison Operators
  “==” — tests for equality.
  “==” — tests for inequality.
  “<”  — tests for less than.
  “>”  — tests for greater than.
  “<=” — tests for less than or equal to
  “>=”  — tests for greater than or equal to
  Comparisons involving a pointer (which is an address) are done 
  as unsigned compares. All other compares are signed.
  
Statements
  expression; An expression, no matter how complex, is considered
    a simple statement.
  if (expression); If the expression is non-zero, the statement 
    is executed , otherwise it isn’t.
  if (expression) statement; else statement; This form of the “if” 
    statement allows the “else” clause. As is the case with most 
    “dangling else” ambiguities, all “else" statements pair with 
    the nearest unmatched “if".
  while (expression) statement; The statement is performed until  
    the expression becomes zero. Since the test is made before the 
    statement is executed the first time, it need not be executed 
    at all.
  break; This statement will cause control to be transferred out 
    of the inner-most “while” loop.
  continue; This statement, used within a “while” loop, will transfer 
    control back to the top of the loop.
  return; This statement does an immediate return from the current 
    function . If a function does not end with this statement, one 
    is performed regardless.
  return expression; This statement allows a function to return a 
    value explicitly.
  ; A semicolon by itself is considered a null statement which does 
    nothing but take the place of a statement. You see this in forms 
    such as: “while (*iptr++ = *jptr++);” where the test itself 
    contains all the necessary parts of the statement.
  {statement; statement;. . . ; statement;} The use of curly brackets 
  (“{ }”) around any group of simple statements is considered a 
  compound statement. A compound statement can be used anywhere a 
  simple statement can. For example: 
    while (1) {x = 3; y = 10; funct(33);}
    or
    if (x< y)
    { print(x);
      total (x);
      --x;
    }
    else
    { type(“all done”);
      x = y;
    }
    
Pseudo-ops
  #include filename — Anywhere this statement appears in the program, 
    the indicated filename will be opened and inserted. The “included” 
    file may not contain an “#include” statement.
  #define name string  — This statement will cause the given name to 
    be replaced by the string throughout the entire program . Normally, 
    it is used to define constants, such as:
      #define tablesize 1000
      #define maxlength 8
    But it can also be used for any sort of text:
      #define jprint 3crs print(12); print(12); print(l2);
    The replacem ent is purely on a text level, and error checking will 
    be performed only after the replacement.
  #asm . . . #endasm  — This structure is not supported by standard C, 
  but it was a feature I felt I needed. It may appear anywhere a statement 
  would, but it passes everything between the word “#asm” and the word 
  “#endasm” right through the parser without intervention. It is intended
  to be used to pass assembly language code through the parsing mechanism. 
  Since it counts as a single statement, allowable (and expected) forms are:
    if (x < y)
      #asm
      LHLD TOTAL
      CALL ADD
      CNC ERROR
      #end asm
    else return;
  This pseudo-op conceivably allows an entire assembly language program to 
  be passed through the compiler. Its intent is to allow machine dependent 
  features (like the 8080’s “IN” and “OUT” instructions to be used without
  writing separate programs).