[BACK]Return to gforth.ds CVS log [TXT] [DIR] Up to [gforth] / gforth / doc

Diff for /gforth/doc/gforth.ds between versions 1.170 and 1.171

version 1.170, 2007/01/21 17:29:54 version 1.171, 2007/02/08 14:07:33
Line 1251  the command line history with cursor key Line 1251  the command line history with cursor key
 @section Syntax  @section Syntax
 @cindex syntax tutorial  @cindex syntax tutorial
   
 A @dfn{word} is a sequence of arbitrary characters (expcept white  A @dfn{word} is a sequence of arbitrary characters (except white
 space).  Words are separated by white space.  E.g., each of the  space).  Words are separated by white space.  E.g., each of the
 following lines contains exactly one word:  following lines contains exactly one word:
   
Line 1597  see + Line 1597  see +
 @cindex stack-effect comments, tutorial  @cindex stack-effect comments, tutorial
 @cindex --, tutorial  @cindex --, tutorial
 By convention the comment after the name of a definition describes the  By convention the comment after the name of a definition describes the
 stack effect: The part in from of the @samp{--} describes the state of  stack effect: The part in front of the @samp{--} describes the state of
 the stack before the execution of the definition, i.e., the parameters  the stack before the execution of the definition, i.e., the parameters
 that are passed into the colon definition; the part behind the @samp{--}  that are passed into the colon definition; the part behind the @samp{--}
 is the state of the stack after the execution of the definition, i.e.,  is the state of the stack after the execution of the definition, i.e.,
Line 1787  If one parameter usually requires only a Line 1787  If one parameter usually requires only a
 a constant), pass it on the top of the stack.  Conversely, parameters  a constant), pass it on the top of the stack.  Conversely, parameters
 that usually require a long sequence of code to compute should be passed  that usually require a long sequence of code to compute should be passed
 as the bottom (i.e., first) parameter.  This makes the code easier to  as the bottom (i.e., first) parameter.  This makes the code easier to
 read, because reader does not need to keep track of the bottom item  read, because the reader does not need to keep track of the bottom item
 through a long sequence of code (or, alternatively, through stack  through a long sequence of code (or, alternatively, through stack
 manipulations). E.g., @code{!} (store, @pxref{Memory}) expects the  manipulations). E.g., @code{!} (store, @pxref{Memory}) expects the
 address on top of the stack because it is usually simpler to compute  address on top of the stack because it is usually simpler to compute
Line 1879  An @code{if}-structure looks like this: Line 1879  An @code{if}-structure looks like this:
 @code{if} takes a flag from the stack.  If the flag is non-zero (true),  @code{if} takes a flag from the stack.  If the flag is non-zero (true),
 the following code is performed, otherwise execution continues after the  the following code is performed, otherwise execution continues after the
 @code{endif} (or @code{else}).  @code{<} compares the top two stack  @code{endif} (or @code{else}).  @code{<} compares the top two stack
 elements and prioduces a flag:  elements and produces a flag:
   
 @example  @example
 1 2 < .  1 2 < .
Line 1950  Gforth supports all combinations of the Line 1950  Gforth supports all combinations of the
 these combinations are standard (for details see the standard,  these combinations are standard (for details see the standard,
 @ref{Numeric comparison}, @ref{Floating Point} or @ref{Word Index}).  @ref{Numeric comparison}, @ref{Floating Point} or @ref{Word Index}).
   
 You can use @code{and or xor invert} can be used as operations on  You can use @code{and or xor invert} as operations on canonical flags.
 canonical flags.  Actually they are bitwise operations:  Actually they are bitwise operations:
   
 @example  @example
 1 2 and .  1 2 and .
Line 2078  Reference: @ref{Simple Loops}. Line 2078  Reference: @ref{Simple Loops}.
   
 @example  @example
 : ^ ( n1 u -- n )  : ^ ( n1 u -- n )
 \ n = the uth power of u1  \ n = the uth power of n1
   1 swap 0 u+do    1 swap 0 u+do
     over *      over *
   loop    loop
Removed from v.1.170  
changed lines
  Added in v.1.171

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>