rust/src/libstd/fmt/parse.rs, branch try

std: Extract format string parsing out of libstd

2014-05-08T16:35:59+00:00

This code does not belong in libstd, and rather belongs in a dedicated crate. In the future, the syntax::ext::format module should move to the fmt_macros crate (hence the name of the crate), but for now the fmt_macros crate will only contain the format string parser. The entire fmt_macros crate is marked #[experimental] because it is not meant for general consumption, only the format!() interface is officially supported, not the internals. This is a breaking change for anyone using the internals of std::fmt::parse. Some of the flags have moved to std::fmt::rt, while the actual parsing support has all moved to the fmt_macros library. [breaking-change]

librustc: Remove `~EXPR`, `~TYPE`, and `~PAT` from the language, except

2014-05-07T06:12:54+00:00

for `~str`/`~[]`. Note that `~self` still remains, since I forgot to add support for `Box` before the snapshot. How to update your code: * Instead of `~EXPR`, you should write `box EXPR`. * Instead of `~TYPE`, you should write `Box`. * Instead of `~PATTERN`, you should write `box PATTERN`. [breaking-change]

Replace most ~exprs with 'box'. #11779

2014-05-03T06:00:58+00:00

std,syntax: make std::fmt::parse use `Vec`s.

2014-04-10T22:21:58+00:00

std: Switch field privacy as necessary

2014-03-31T22:17:12+00:00

libstd: Document the following modules:

2014-03-25T17:12:49+00:00

* native::io * std::char * std::fmt * std::fmt::parse * std::io * std::io::extensions * std::io::net::ip * std::io::net::udp * std::io::net::unix * std::io::pipe * std::num * std::num::f32 * std::num::f64 * std::num::strconv * std::os

use TotalEq for HashMap

2014-03-23T05:59:11+00:00

Closes #5283

std: Change assert_eq!() to use {} instead of {:?}

2014-03-01T07:01:54+00:00

Formatting via reflection has been a little questionable for some time now, and it's a little unfortunate that one of the standard macros will silently use reflection when you weren't expecting it. This adds small bits of code bloat to libraries, as well as not always being necessary. In light of this information, this commit switches assert_eq!() to using {} in the error message instead of {:?}. In updating existing code, there were a few error cases that I encountered: * It's impossible to define Show for [T, ..N]. I think DST will alleviate this because we can define Show for [T]. * A few types here and there just needed a #[deriving(Show)] * Type parameters needed a Show bound, I often moved this to `assert!(a == b)` * `Path` doesn't implement `Show`, so assert_eq!() cannot be used on two paths. I don't think this is much of a regression though because {:?} on paths looks awful (it's a byte array). Concretely speaking, this shaved 10K off a 656K binary. Not a lot, but sometime significant for smaller binaries.

Transition to new `Hash`, removing IterBytes and std::to_bytes.

2014-02-23T20:44:10+00:00

Remove std::condition

2014-02-06T23:48:56+00:00

This has been a long time coming. Conditions in rust were initially envisioned as being a good alternative to error code return pattern. The idea is that all errors are fatal-by-default, and you can opt-in to handling the error by registering an error handler. While sounding nice, conditions ended up having some unforseen shortcomings: * Actually handling an error has some very awkward syntax: let mut result = None; let mut answer = None; io::io_error::cond.trap(|e| { result = Some(e) }).inside(|| { answer = Some(some_io_operation()); }); match result { Some(err) => { /* hit an I/O error */ } None => { let answer = answer.unwrap(); /* deal with the result of I/O */ } } This pattern can certainly use functions like io::result, but at its core actually handling conditions is fairly difficult * The "zero value" of a function is often confusing. One of the main ideas behind using conditions was to change the signature of I/O functions. Instead of read_be_u32() returning a result, it returned a u32. Errors were notified via a condition, and if you caught the condition you understood that the "zero value" returned is actually a garbage value. These zero values are often difficult to understand, however. One case of this is the read_bytes() function. The function takes an integer length of the amount of bytes to read, and returns an array of that size. The array may actually be shorter, however, if an error occurred. Another case is fs::stat(). The theoretical "zero value" is a blank stat struct, but it's a little awkward to create and return a zero'd out stat struct on a call to stat(). In general, the return value of functions that can raise error are much more natural when using a Result as opposed to an always-usable zero-value. * Conditions impose a necessary runtime requirement on *all* I/O. In theory I/O is as simple as calling read() and write(), but using conditions imposed the restriction that a rust local task was required if you wanted to catch errors with I/O. While certainly an surmountable difficulty, this was always a bit of a thorn in the side of conditions. * Functions raising conditions are not always clear that they are raising conditions. This suffers a similar problem to exceptions where you don't actually know whether a function raises a condition or not. The documentation likely explains, but if someone retroactively adds a condition to a function there's nothing forcing upstream users to acknowledge a new point of task failure. * Libaries using I/O are not guaranteed to correctly raise on conditions when an error occurs. In developing various I/O libraries, it's much easier to just return `None` from a read rather than raising an error. The silent contract of "don't raise on EOF" was a little difficult to understand and threw a wrench into the answer of the question "when do I raise a condition?" Many of these difficulties can be overcome through documentation, examples, and general practice. In the end, all of these difficulties added together ended up being too overwhelming and improving various aspects didn't end up helping that much. A result-based I/O error handling strategy also has shortcomings, but the cognitive burden is much smaller. The tooling necessary to make this strategy as usable as conditions were is much smaller than the tooling necessary for conditions. Perhaps conditions may manifest themselves as a future entity, but for now we're going to remove them from the standard library. Closes #9795 Closes #8968