diff options
author | 2011-12-03 09:44:07 -0500 | |
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committer | 2011-12-03 09:44:07 -0500 | |
commit | 0f14aa67e5446391904c6a4d2ee7b4f00b803158 (patch) | |
tree | 55e7ce9758b2233896d59392e6b86614abab533a | |
parent | fa906ca9e2e31d809221badd35ba1e93eaf3a8e5 (diff) |
Catching integer divisions by zero
-rw-r--r-- | lib/js/urweb.js | 4 | ||||
-rw-r--r-- | src/cjr_print.sml | 42 | ||||
-rw-r--r-- | src/jscomp.sml | 2 | ||||
-rw-r--r-- | src/monoize.sml | 2 | ||||
-rw-r--r-- | tests/div.ur | 43 |
5 files changed, 88 insertions, 5 deletions
diff --git a/lib/js/urweb.js b/lib/js/urweb.js index d7bb7b6f..f05957a0 100644 --- a/lib/js/urweb.js +++ b/lib/js/urweb.js @@ -19,9 +19,9 @@ function plus(x, y) { return x + y; } function minus(x, y) { return x - y; } function times(x, y) { return x * y; } function div(x, y) { return x / y; } -function divInt(x, y) { var n = x / y; return n < 0 ? Math.ceil(n) : Math.floor(n); } +function divInt(x, y) { if (y == 0) er("Division by zero"); var n = x / y; return n < 0 ? Math.ceil(n) : Math.floor(n); } function mod(x, y) { return x % y; } -function modInt(x, y) { var n = x % y; return n < 0 ? Math.ceil(n) : Math.floor(n); } +function modInt(x, y) { if (y == 0) er("Division by zero"); var n = x % y; return n < 0 ? Math.ceil(n) : Math.floor(n); } function lt(x, y) { return x < y; } function le(x, y) { return x <= y; } diff --git a/src/cjr_print.sml b/src/cjr_print.sml index ddeb8ea5..2c4f7b36 100644 --- a/src/cjr_print.sml +++ b/src/cjr_print.sml @@ -1655,7 +1655,7 @@ fun p_exp' par tail env (e, loc) = p_exp' true false env e1]) | EBinop (s, e1, e2) => - if Char.isAlpha (String.sub (s, size s - 1)) then + if s <> "fdiv" andalso Char.isAlpha (String.sub (s, size s - 1)) then box [string s, string "(", p_exp' false false env e1, @@ -1663,10 +1663,48 @@ fun p_exp' par tail env (e, loc) = space, p_exp' false false env e2, string ")"] + else if s = "/" orelse s = "%" then + box [string "({", + newline, + string "uw_Basis_int", + space, + string "dividend", + space, + string "=", + space, + p_exp env e1, + string ",", + space, + string "divisor", + space, + string "=", + space, + p_exp env e2, + string ";", + newline, + string "if", + space, + string "(divisor", + space, + string "==", + space, + string "0)", + newline, + box [string "uw_error(ctx, FATAL, \"", + string (ErrorMsg.spanToString loc), + string ": division by zero\");", + newline], + string "dividend", + space, + string s, + space, + string "divisor;", + newline, + string "})"] else parenIf par (box [p_exp' true false env e1, space, - string s, + string (if s = "fdiv" then "/" else s), space, p_exp' true false env e2]) diff --git a/src/jscomp.sml b/src/jscomp.sml index 43c16cc3..3e475899 100644 --- a/src/jscomp.sml +++ b/src/jscomp.sml @@ -706,6 +706,8 @@ fun process file = | "*" => "times" | "/" => (case bi of Int => "divInt" | NotInt => "div") | "%" => (case bi of Int => "modInt" | NotInt => "mod") + | "fdiv" => "div" + | "fmod" => "mod" | "<" => "lt" | "<=" => "le" | "strcmp" => "strcmp" diff --git a/src/monoize.sml b/src/monoize.sml index 4a70c012..e4ed6562 100644 --- a/src/monoize.sml +++ b/src/monoize.sml @@ -1031,7 +1031,7 @@ fun monoExp (env, st, fm) (all as (e, loc)) = floatBin "+", floatBin "-", floatBin "*", - floatBin "/", + floatBin "fdiv", floatBin "fmod") end diff --git a/tests/div.ur b/tests/div.ur new file mode 100644 index 00000000..69a09275 --- /dev/null +++ b/tests/div.ur @@ -0,0 +1,43 @@ +functor Make(M : sig + type t + val read_t : read t + val show_t : show t + val num_t : num t + end) = struct + fun calculate (n1, n2) = return <xml><body> + {[readError n1 / readError n2 : M.t]}<br/> + {[readError n1 % readError n2 : M.t]}<br/> + </body></xml> + + fun main () = + s1 <- source ""; + s2 <- source ""; + s3 <- source ""; + s4 <- source ""; + return <xml><body> + <h1>Client-side</h1> + + <ctextbox source={s1}/> / <ctextbox source={s2}/> + <button value="=" onclick={n1 <- get s1; + n2 <- get s2; + set s3 (show (readError n1 / readError n2 : M.t)); + set s4 (show (readError n1 % readError n2 : M.t))}/> + <dyn signal={n <- signal s3; return (txt n)}/>, + <dyn signal={n <- signal s4; return (txt n)}/> + + <h1>Server-side</h1> + + <form> + <textbox{#1}/> / <textbox{#2}/> + <submit value="=" action={calculate}/> + </form> + </body></xml> +end + +structure Int = Make(struct type t = int end) +structure Float = Make(struct type t = float end) + +fun main () : transaction page = return <xml><body> + <li><a link={Int.main ()}>Int</a></li> + <li><a link={Float.main ()}>Float</a></li> +</body></xml> |