c - Confusing language in specification of strtol, et al -



c - Confusing language in specification of strtol, et al -

the specification strtol conceptually divides input string "initial whitespace", "subject sequence", , "final string", , defines "subject sequence" as:

the longest initial subsequence of input string, starting first non-white-space character of expected form. subject sequence shall contain no characters if input string empty or consists exclusively of white-space characters, or if first non-white-space character other sign or permissible letter or digit.

at 1 time thought "longest initial subsequence" business akin way scanf works, "0x@" scan "0x", failed match, followed "@" next unread character. however, after discussion, i'm convinced strtol processes longest initial subsequence of expected form, not longest initial string initial subsequence of possible string of expected form.

what's still confusing me language in specification:

if subject sequence empty or not have expected form, no conversion performed; value of str stored in object pointed endptr, provided endptr not null pointer.

if take seems right definition of "subject sequence", there no such thing non-empty subject sequence not have expected form, , instead (to avoid redundancy , confusion) text should read:

if subject sequence empty, no conversion performed; value of str stored in object pointed endptr, provided endptr not null pointer.

can clarify these issues me? perhaps link past discussions or relevant defect reports useful.

i think c99 language quite clear:

the subject sequence defined longest initial subsequence of input string, starting first non-white-space character, of expected form.

given "0x@", "0x@" not of expected form; "0x" not of expected form; hence "0" longest initial subsequence of expected form.

i agree implies cannot have non-empty subject sequence isn't of expected form - unless interpret following:

in other "c" locale, additional locale-specific subject sequence forms may accepted.

...as allowing locale define other possible forms subject sequence might have, nonetheless not of "the expected form".

the wording in final paragraph seems "belt-and-braces".

c standards-compliance language-lawyer strtol

Comments

Post a Comment

Popular posts from this blog

iphone - Dismissing a UIAlertView -

iphone - Dismissing a UIAlertView - i set in app purchase app, , when user taps button, purchase started. basically, tap button, , depending on speed on net connection, waiting 10 seconds until new alert view comes asking if purchase product. user tap button multiple times since nil came up, , multiple purchase alert views come up. additionally, maybe seen user app bug. in end, problem. i want alert view come spinning wheel says "loading..." when users taps purchase button. problem is, how dismiss when new alert view comes asking user if want purchase product? if ([uialertview alloc] says: @"whatever apple's alert view says") { //dismiss "loading..." alert view here } i uncertainty work, input appreciated. thanks! you need have access alertview. can this. create alertview instance var in app delegate , when want show loading initialize instance var assign property , when want dismiss phone call [alertviewinstance d...
Read more

intellij idea - Update external libraries with intelij and java -

intellij idea - Update external libraries with intelij and java - simple plenty really. i'm using apache jars, i'll create changes jar's every often. these jars listed external libs in intelij (i.e classpath looking install dir of jar's). when create changes intelij doesn't seem know new implementation. have remove jar external library , re-ad it. does know have intelij picks changes automatically ? i've done clean , rebuild project had little effect. you can go preferences -> build, execution, deployment -> build tools -> maven -> importing , check box says import maven projects automatically . in mac, can command + shift + a , come in action reimport , click on reimport maven projects . intellij-idea
Read more

javascript - send data from a new window to previous window in php -

javascript - send data from a new window to previous window in php - i have image in main.php file : <img src="..\images\image.gif" class="cur" onclick="imgwin();"> when click on image below function has called : function imgwin() { imagewin=window.open("../pages/img.php","imagewin","toolbar=no,width=500,height=200,directories=no,menubar=no,scrollbars=yes"); } this function opens img.php in new window img.php file : <html> <head> <title>upload image</title> </head> <body> <form name="imgform" method="get" action="#"> address : <input type="file" name="imgurl" size="50"> description : <input type="text" name="description" size="50"> <input type="submit" value="sumbit...
Read more