std.fmt: breaking API changes

added adapter to AnyWriter and GenericWriter to help bridge the gap
between old and new API

make std.testing.expectFmt work at compile-time

std.fmt no longer has a dependency on std.unicode. Formatted printing
was never properly unicode-aware. Now it no longer pretends to be.

Breakage/deprecations:
* std.fs.File.reader -> std.fs.File.deprecatedReader
* std.fs.File.writer -> std.fs.File.deprecatedWriter
* std.io.GenericReader -> std.io.Reader
* std.io.GenericWriter -> std.io.Writer
* std.io.AnyReader -> std.io.Reader
* std.io.AnyWriter -> std.io.Writer
* std.fmt.format -> std.fmt.deprecatedFormat
* std.fmt.fmtSliceEscapeLower -> std.ascii.hexEscape
* std.fmt.fmtSliceEscapeUpper -> std.ascii.hexEscape
* std.fmt.fmtSliceHexLower -> {x}
* std.fmt.fmtSliceHexUpper -> {X}
* std.fmt.fmtIntSizeDec -> {B}
* std.fmt.fmtIntSizeBin -> {Bi}
* std.fmt.fmtDuration -> {D}
* std.fmt.fmtDurationSigned -> {D}
* {} -> {f} when there is a format method
* format method signature
  - anytype -> *std.io.Writer
  - inferred error set -> error{WriteFailed}
  - options -> (deleted)
* std.fmt.Formatted
  - now takes context type explicitly
  - no fmt string

1 files changed, 7 insertions, 13 deletions

diff --git a/lib/std/SemanticVersion.zig b/lib/std/SemanticVersion.zig
index 7cb3888e54..50b146d74f 100644
--- a/lib/std/SemanticVersion.zig
+++ b/lib/std/SemanticVersion.zig
@@ -150,17 +150,11 @@ fn parseNum(text: []const u8) error{ InvalidVersion, Overflow }!usize {
     };
 }
 
-pub fn format(
-    self: Version,
-    comptime fmt: []const u8,
-    options: std.fmt.FormatOptions,
-    out_stream: anytype,
-) !void {
-    _ = options;
+pub fn format(self: Version, w: *std.io.Writer, comptime fmt: []const u8) std.io.Writer.Error!void {
     if (fmt.len != 0) std.fmt.invalidFmtError(fmt, self);
-    try std.fmt.format(out_stream, "{d}.{d}.{d}", .{ self.major, self.minor, self.patch });
-    if (self.pre) |pre| try std.fmt.format(out_stream, "-{s}", .{pre});
-    if (self.build) |build| try std.fmt.format(out_stream, "+{s}", .{build});
+    try w.print("{d}.{d}.{d}", .{ self.major, self.minor, self.patch });
+    if (self.pre) |pre| try w.print("-{s}", .{pre});
+    if (self.build) |build| try w.print("+{s}", .{build});
 }
 
 const expect = std.testing.expect;
@@ -202,7 +196,7 @@ test format {
         "1.0.0+0.build.1-rc.10000aaa-kk-0.1",
         "5.4.0-1018-raspi",
         "5.7.123",
-    }) |valid| try std.testing.expectFmt(valid, "{}", .{try parse(valid)});
+    }) |valid| try std.testing.expectFmt(valid, "{f}", .{try parse(valid)});
 
     // Invalid version strings should be rejected.
     for ([_][]const u8{
@@ -269,12 +263,12 @@ test format {
     // Valid version string that may overflow.
     const big_valid = "99999999999999999999999.999999999999999999.99999999999999999";
     if (parse(big_valid)) |ver| {
-        try std.testing.expectFmt(big_valid, "{}", .{ver});
+        try std.testing.expectFmt(big_valid, "{f}", .{ver});
     } else |err| try expect(err == error.Overflow);
 
     // Invalid version string that may overflow.
     const big_invalid = "99999999999999999999999.999999999999999999.99999999999999999----RC-SNAPSHOT.12.09.1--------------------------------..12";
-    if (parse(big_invalid)) |ver| std.debug.panic("expected error, found {}", .{ver}) else |_| {}
+    if (parse(big_invalid)) |ver| std.debug.panic("expected error, found {f}", .{ver}) else |_| {}
 }
 
 test "precedence" {