Adding infix and parsing example.

examples/infix/parsing.fs

@@ -0,0 +1,21 @@
+: kind ( "name" -- )
+   create 0 ,
+   does> @ begin dup while
+             state @ >r   here >r   >in @ >r
+             dup >r @ catch 0= if rdrop rdrop rdrop rdrop exit then
+             r> cell+ @
+             r> >in !   r> here - allot    r> state !
+         repeat
+         -1 throw ;
+: :{{   >body :noname ;
+: {{   latestxt :{{ ;
+: }}   postpone ; here >r , dup @ , r> swap ! ; immediate
+: @token ( -- ch ) >in @ tib + c@ ;
+: +token   1 >in +! ;
+: =token ( ch -- ) @token <> throw +token ;
+: within ( ch a b ) >r over <= swap r> <= and ;
+: []token ( a b -- ch ) @token -rot within 0= throw @token +token ;
+: t'   postpone [char] postpone =token ; immediate
+: stoken ( a n -- ) 0 ?do dup c@ =token 1+ loop drop ;
+: t"   postpone s" postpone stoken ; immediate
+