--- gforth/extend.fs 1999/03/23 20:24:18 1.33 +++ gforth/extend.fs 2000/02/04 14:52:30 1.37 @@ -26,7 +26,7 @@ decimal \ .( 12may93jaw : .( ( "ccc" -- ) \ core-ext dot-paren - \G Parse a string @var{ccc} delimited by a @code{)} (right + \G Parse a string @i{ccc} delimited by a @code{)} (right \G parenthesis). Display the string. This is often used to display \G progress information during compilation; see examples below. [char] ) parse type ; immediate @@ -36,7 +36,7 @@ decimal \ !! 2value : 2Literal ( compilation w1 w2 -- ; run-time -- w1 w2 ) \ double two-literal - \G Compile appropriate code such that, at run-time, cell pair @var{w1, w2} are + \G Compile appropriate code such that, at run-time, cell pair @i{w1, w2} are \G placed on the stack. Interpretation semantics are undefined. swap postpone Literal postpone Literal ; immediate restrict @@ -76,43 +76,48 @@ decimal postpone (c") here over char+ allot place align ; immediate restrict : C" ( compilation "ccc" -- ; run-time -- c-addr ) \ core-ext c-quote - \G Compilation: parse a string @var{ccc} delimited by a @code{"} - \G (double quote). At run-time, return @var{c-addr} which - \G specifies the counted string @var{ccc}. Interpretation + \G Compilation: parse a string @i{ccc} delimited by a @code{"} + \G (double quote). At run-time, return @i{c-addr} which + \G specifies the counted string @i{ccc}. Interpretation \G semantics are undefined. [char] " parse postpone CLiteral ; immediate restrict \ [COMPILE] 17may93jaw : [compile] ( compilation "name" -- ; run-time ? -- ? ) \ core-ext bracket-compile - comp' drop compile, ; immediate + comp' drop + dup [ comp' exit drop ] literal = if + execute \ EXIT has default compilation semantics, perform them + else + compile, + then ; immediate \ CONVERT 17may93jaw : convert ( ud1 c-addr1 -- ud2 c-addr2 ) \ core-ext - \G OBSOLESCENT; superseded by @code{>number}. + \G OBSOLESCENT: superseded by @code{>number}. char+ true >number drop ; \ ERASE 17may93jaw : erase ( addr len -- ) \ core-ext - \G If @var{len}>0, clear all bits in each location of a memory region - \G of @var{len} address units starting at address @var{addr}. + \G If @i{len}>0, clear all bits in each location of a memory region + \G of @i{len} address units starting at address @i{addr}. \ !! dependence on "1 chars 1 =" ( 0 1 chars um/mod nip ) 0 fill ; -: blank ( addr len -- ) \ string - \G If @var{len}>0, store the character value for a space in each +: blank ( c-addr u -- ) \ string + \G If @i{u}>0, store the character value for a space in each \G location of a memory region - \G of @var{len} character units starting at address @var{addr}. + \G of @i{u} character units starting at address @i{c-addr}. bl fill ; \ SEARCH 02sep94py : search ( c-addr1 u1 c-addr2 u2 -- c-addr3 u3 flag ) \ string - \G Search the string specified by @var{c-addr1, u1} for the string - \G specified by @var{c-addr2, u2}. If @var{flag} is true: match was found - \G at @var{c-addr3} with @var{u3} characters remaining. If @var{flag} is false: - \G no match was found; @var{c-addr3, u3} are equal to @var{c-addr1, u1}. + \G Search the string specified by @i{c-addr1, u1} for the string + \G specified by @i{c-addr2, u2}. If @i{flag} is true: match was found + \G at @i{c-addr3} with @i{u3} characters remaining. If @i{flag} is false: + \G no match was found; @i{c-addr3, u3} are equal to @i{c-addr1, u1}. \ not very efficient; but if we want efficiency, we'll do it as primitive 2>r 2dup begin @@ -128,9 +133,16 @@ decimal \ SOURCE-ID SAVE-INPUT RESTORE-INPUT 11jun93jaw : source-id ( -- 0 | -1 | fileid ) \ core-ext,file source-i-d - loadfile @ dup 0= IF drop sourceline# 0 min THEN ; - -: save-input ( -- x1 .. xn n ) \ core-ext + \G Return 0 (the input source is the user input device), -1 (the + \G input source is a string being processed by @code{evaluate}) or + \G a @i{fileid} (the input source is the file specified by + \G @i{fileid}). + loadfile @ dup 0= IF drop sourceline# 0 min THEN ; + +: save-input ( -- xn .. x1 n ) \ core-ext + \G The @i{n} entries @i{xn - x1} describe the current state of the + \G input source specification, in some platform-dependent way that can + \G be used by @code{restore-input}. >in @ loadfile @ if @@ -144,7 +156,11 @@ decimal source-id 6 ; -: restore-input ( x1 .. xn n -- flag ) \ core-ext +: restore-input ( xn .. x1 n -- flag ) \ core-ext + \G Attempt to restore the input source specification to the state + \G described by the @i{n} entries @i{xn - x1}. @i{flag} is + \G true if the restore fails. In Gforth it fails pretty often + \G (and sometimes with a @code{throw}). 6 <> -12 and throw source-id <> -12 and throw >tib ! @@ -168,11 +184,18 @@ decimal \ EXPECT SPAN 17may93jaw -variable span ( -- a-addr ) \ core-ext -\ obsolescent - -: expect ( c-addr +len -- ) \ core-ext - \ obsolescent; use accept +variable span ( -- c-addr ) \ core-ext +\G @code{Variable} -- @i{c-addr} is the address of a cell that stores the +\G length of the last string received by @code{expect}. OBSOLESCENT. + +: expect ( c-addr +n -- ) \ core-ext + \G Receive a string of at most @i{+n} characters, and store it + \G in memory starting at @i{c-addr}. The string is + \G displayed. Input terminates when the key is pressed or + \G @i{+n} characters have been received. The normal Gforth line + \G editing capabilites are available. The length of the string is + \G stored in @code{span}; it does not include the + \G character. OBSOLESCENT: superceeded by @code{accept}. 0 rot over BEGIN ( maxlen span c-addr pos1 ) key decode ( maxlen span c-addr pos2 flag ) @@ -255,7 +278,7 @@ variable span ( -- a-addr ) \ core-ext THEN ; : marker ( " name" -- ) \ core-ext - \G Create a definition, @var{name} (called a @var{mark}) whose + \G Create a definition, @i{name} (called a @i{mark}) whose \G execution semantics are to remove itself and everything \G defined after it. marker, Create A,