diff options
Diffstat (limited to 'lib/operators.nom')
| -rw-r--r-- | lib/operators.nom | 109 |
1 files changed, 38 insertions, 71 deletions
diff --git a/lib/operators.nom b/lib/operators.nom index cdf41fe..8ea7aad 100644 --- a/lib/operators.nom +++ b/lib/operators.nom @@ -57,84 +57,51 @@ compile [%var or= %val] to code: "\(%var as lua) = \(%var as lua) or \(%val as l compile [%var join= %val] to code: "\(%var as lua) = \(%var as lua) .. \(%val as lua);" compile [%var mod= %val] to code: "\(%var as lua) = \(%var as lua) % \(%val as lua);" -# Binary Operators -lua do> ".." - local binops = {"-","/","<","<=",">",">=","^",{"===","=="},{"!==","~="},{"mod","%"}}; - for _,op in ipairs(binops) do - local nomsu_alias = op; - if type(op) == 'table' then; - nomsu_alias, op = unpack(op); - end - nomsu:defmacro("%a "..nomsu_alias.." %b", (function(nomsu, vars) - return "("..nomsu:tree_to_lua(\%a).." "..op.." "..nomsu:tree_to_lua(\%b)..")"; - end), [["(\\%a ]]..op..[[ \\%b)"]]); - end +# Math Operators +compile [%x + %y] to: "(\(%x as lua) + \(%y as lua))" +compile [%x - %y] to: "(\(%x as lua) - \(%y as lua))" +compile [%x * %y] to: "(\(%x as lua) * \(%y as lua))" +compile [%x / %y] to: "(\(%x as lua) / \(%y as lua))" +compile [%x ^ %y] to: "(\(%x as lua) ^ \(%y as lua))" +compile [%x mod %y] to: "(\(%x as lua) % \(%y as lua))" + +# Comparison Operators +compile [%x < %y] to: "(\(%x as lua) < \(%y as lua))" +compile [%x > %y] to: "(\(%x as lua) > \(%y as lua))" +compile [%x <= %y] to: "(\(%x as lua) <= \(%y as lua))" +compile [%x >= %y] to: "(\(%x as lua) >= \(%y as lua))" +# == and != do equivalence checking, rather than identity checking +compile [%a == %b] to: "nomsu.utils.equivalent(\(%a as lua), \(%b as lua))" +compile [%a != %b] to: "(not nomsu.utils.equivalent(\(%a as lua), \(%b as lua)))" +# For strict identity checking: +compile [%x === %y] to: "(\(%x as lua) == \(%y as lua))" +compile [%x !== %y] to: "(\(%x as lua) ~= \(%y as lua))" + +# 3-part chained comparisons +# (uses a lambda to avoid re-evaluating middle value, while still being an expression) +parse [%x < %y < %z] as: =lua "(function(x,y,z) return x < y and y < z; end)(\%x,\%y,\%z)" +parse [%x <= %y < %z] as: =lua "(function(x,y,z) return x <= y and y < z; end)(\%x,\%y,\%z)" +parse [%x < %y <= %z] as: =lua "(function(x,y,z) return x < y and y <= z; end)(\%x,\%y,\%z)" +parse [%x <= %y <= %z] as: =lua "(function(x,y,z) return x <= y and y <= z; end)(\%x,\%y,\%z)" +parse [%x > %y > %z] as: =lua "(function(x,y,z) return x > y and y > z; end)(\%x,\%y,\%z)" +parse [%x >= %y > %z] as: =lua "(function(x,y,z) return x >= y and y > z; end)(\%x,\%y,\%z)" +parse [%x > %y >= %z] as: =lua "(function(x,y,z) return x > y and y >= z; end)(\%x,\%y,\%z)" +parse [%x >= %y >= %z] as: =lua "(function(x,y,z) return x >= y and y >= z; end)(\%x,\%y,\%z)" +# TODO: optimize for common case where x,y,z are all either variables or number literals + +# Boolean Operators +compile [%x and %y] to: "(\(%x as lua) and \(%y as lua))" +compile [%x or %y] to: "(\(%x as lua) or \(%y as lua))" -# TODO: implement OR, XOR, AND for multiple operands +# Bitwise Operators compile [%a OR %b, %a | %b] to: "bit32.bor(\(%a as lua), \(%b as lua))" compile [%a XOR %b] to: "bit32.bxor(\(%a as lua), \(%b as lua))" compile [%a AND %b, %a & %b] to: "bit32.band(\(%a as lua), \(%b as lua))" compile [NOT %, ~ %] to: "bit32.bnot(\(% as lua))" compile [%x LSHIFT %shift, %x << %shift] to: "bit32.lshift(\(%x as lua), \(%shift as lua))" -compile [%x RSHIFT %shift] to: "bit32.rshift(\(%x as lua), \(%shift as lua))" +compile [%x RSHIFT %shift, %x >>> %shift] to: "bit32.rshift(\(%x as lua), \(%shift as lua))" compile [%x ARSHIFT %shift, %x >> %shift] to: "bit32.arshift(\(%x as lua), \(%shift as lua))" -# == and != do equivalence checking, rather than identity checking -compile [%a == %b] to: "nomsu.utils.equivalent(\(%a as lua), \(%b as lua))" -compile [%a != %b] to: "(not nomsu.utils.equivalent(\(%a as lua), \(%b as lua)))" - -# Commutative Operators defined for up to 8 operands -# TODO: work out solution for commutative operators using more clever macros -lua do> ".." - local max_operands = 8; - local comops = {"+","*","and","or"}; - for _,_op in ipairs(comops) do - local op = _op; - local spec = "%1 "; - for n=2,max_operands do - spec = spec .." "..op.." %"..tostring(n); - nomsu:defmacro(spec, (function(nomsu, vars) - local bits = {}; - for i=1,n do - table.insert(bits, (nomsu:tree_to_lua(vars[tostring(i)]))); - end - return "("..table.concat(bits, " "..op.." ")..")"; - end)); - end - end - -# Chained compairsions (e.g. x < y <= z) are defined up to 3 operands -lua do> ".." - local max_operands = 3; - for _,chainers in ipairs({{"<","<="},{">",">="}}) do - local function recurse(chainers, chain) - -- The 1-op versions are already more efficiently defined, and a 0-op version doesnt make sense - if #chain >= 2 then; - local spec = "%1"; - for i,op in ipairs(chain) do - spec = spec .. " "..op.." %"..tostring(i+1); - end - -- Chained comparisons need to be functions to avoid re-evaluating their arguments : - nomsu:def(spec, function(nomsu, vars) - for i,op in ipairs(chain) do - local a, b, result = vars[tostring(i)], vars[tostring(i+1)]; - if op == "<" then; result = a < b; - elseif op == "<=" then; result = a <= b; - elseif op == ">" then; result = a > b; - elseif op == ">=" then; result = a >= b; end - -- Short circuit - if not result then; return false; end - end - end); - end - if #chain + 1 >= max_operands then; return; end - for _,c in ipairs(chainers) do - table.insert(chain, c); - recurse(chainers, chain); - table.remove(chain); - end - end - recurse(chainers, {}); - end +# TODO: implement OR, XOR, AND for multiple operands? # Unary operators compile [- %] to: "-(\(% as lua))" |