@@ -20,16 +20,19 @@ # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE # SOFTWARE. -# A grammar for simple arithmetic. +# A grammar for an arithmetic calculator. +# Supports +,-,*,/, negation, parentheses and floating point numbers. -Calc <- Ws ?(Id :'=' Ws) Sum +calc <- ws sum -Id <- +[a-zA-Z] Ws +sum <- prod *([+-] ws prod) -Sum <= Prod *([+-] Ws Prod) +prod <- unary *([*/] ws unary) -Prod <= Num *([*/] Ws Num) +unary <= '-' ws unary + | :'(' ws sum :')' ws + | num -Num <- +[0-9] Ws +num <- +[0-9] ?('.' +[0-9]) ws -Ws <: *[ \t\n\r] +ws <: *[ \t\n\r] grammars/calc.waxeye 6c42615ce42e395f8742e0631d9a7213f500cabd Orlando D. A. R. Hill orlandodarhill http://github.com/orlandodarhill/waxeye/commit/5234db566c74ccea68337ef5cac1a4cff4720902 5234db566c74ccea68337ef5cac1a4cff4720902 2008-11-11T09:40:32-08:00 2008-11-11T09:40:32-08:00 Improved the calc grammar. ebd50b753c5c15a192a65efd4d5a637ff6d158e6 Orlando D. A. R. Hill orlandodarhill