zig/lib/std/fmt.zig
Andrew Kelley bf3ac66150
remove type coercion from array values to references
* Implements #3768. This is a sweeping breaking change that requires
   many (trivial) edits to Zig source code. Array values no longer
   coerced to slices; however one may use `&` to obtain a reference to
   an array value, which may then be coerced to a slice.

 * Adds `IrInstruction::dump`, for debugging purposes. It's useful to
   call to inspect the instruction when debugging Zig IR.

 * Fixes bugs with result location semantics. See the new behavior test
   cases, and compile error test cases.

 * Fixes bugs with `@typeInfo` not properly resolving const values.

 * Behavior tests are passing but std lib tests are not yet. There
   is more work to do before merging this branch.
2019-11-27 03:37:50 -05:00

1697 lines
59 KiB
Zig

const std = @import("std.zig");
const math = std.math;
const assert = std.debug.assert;
const mem = std.mem;
const builtin = @import("builtin");
const errol = @import("fmt/errol.zig");
const lossyCast = std.math.lossyCast;
pub const default_max_depth = 3;
pub const Alignment = enum {
Left,
Center,
Right,
};
pub const FormatOptions = struct {
precision: ?usize = null,
width: ?usize = null,
alignment: ?Alignment = null,
fill: u8 = ' ',
};
fn nextArg(comptime used_pos_args: *u32, comptime maybe_pos_arg: ?comptime_int, comptime next_arg: *comptime_int) comptime_int {
if (maybe_pos_arg) |pos_arg| {
used_pos_args.* |= 1 << pos_arg;
return pos_arg;
} else {
const arg = next_arg.*;
next_arg.* += 1;
return arg;
}
}
fn peekIsAlign(comptime fmt: []const u8) bool {
// Should only be called during a state transition to the format segment.
comptime assert(fmt[0] == ':');
inline for (([_]u8{ 1, 2 })[0..]) |i| {
if (fmt.len > i and (fmt[i] == '<' or fmt[i] == '^' or fmt[i] == '>')) {
return true;
}
}
return false;
}
/// Renders fmt string with args, calling output with slices of bytes.
/// If `output` returns an error, the error is returned from `format` and
/// `output` is not called again.
///
/// The format string must be comptime known and may contain placeholders following
/// this format:
/// `{[position][specifier]:[fill][alignment][width].[precision]}`
///
/// Each word between `[` and `]` is a parameter you have to replace with something:
///
/// - *position* is the index of the argument that should be inserted
/// - *specifier* is a type-dependent formatting option that determines how a type should formatted (see below)
/// - *fill* is a single character which is used to pad the formatted text
/// - *alignment* is one of the three characters `<`, `^` or `>`. they define if the text is *left*, *center*, or *right* aligned
/// - *width* is the total width of the field in characters
/// - *precision* specifies how many decimals a formatted number should have
///
/// Note that most of the parameters are optional and may be omitted. Also you can leave out separators like `:` and `.` when
/// all parameters after the separator are omitted.
/// Only exception is the *fill* parameter. If *fill* is required, one has to specify *alignment* as well, as otherwise
/// the digits after `:` is interpreted as *width*, not *fill*.
///
/// The *specifier* has several options for types:
/// - `x` and `X`:
/// - format the non-numeric value as a string of bytes in hexadecimal notation ("binary dump") in either lower case or upper case
/// - output numeric value in hexadecimal notation
/// - `s`: print a pointer-to-many as a c-string, use zero-termination
/// - `B` and `Bi`: output a memory size in either metric (1000) or power-of-two (1024) based notation. works for both float and integer values.
/// - `e`: output floating point value in scientific notation
/// - `d`: output numeric value in decimal notation
/// - `b`: output integer value in binary notation
/// - `c`: output integer as an ASCII character. Integer type must have 8 bits at max.
/// - `*`: output the address of the value instead of the value itself.
///
/// If a formatted user type contains a function of the type
/// ```
/// fn format(value: ?, comptime fmt: []const u8, options: std.fmt.FormatOptions, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void) Errors!void
/// ```
/// with `?` being the type formatted, this function will be called instead of the default implementation.
/// This allows user types to be formatted in a logical manner instead of dumping all fields of the type.
///
/// A user type may be a `struct`, `union` or `enum` type.
pub fn format(
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
comptime fmt: []const u8,
args: ...,
) Errors!void {
const ArgSetType = @IntType(false, 32);
if (args.len > ArgSetType.bit_count) {
@compileError("32 arguments max are supported per format call");
}
const State = enum {
Start,
Positional,
CloseBrace,
Specifier,
FormatFillAndAlign,
FormatWidth,
FormatPrecision,
};
comptime var start_index = 0;
comptime var state = State.Start;
comptime var next_arg = 0;
comptime var maybe_pos_arg: ?comptime_int = null;
comptime var used_pos_args: ArgSetType = 0;
comptime var specifier_start = 0;
comptime var specifier_end = 0;
comptime var options = FormatOptions{};
inline for (fmt) |c, i| {
switch (state) {
.Start => switch (c) {
'{' => {
if (start_index < i) {
try output(context, fmt[start_index..i]);
}
start_index = i;
specifier_start = i + 1;
specifier_end = i + 1;
maybe_pos_arg = null;
state = .Positional;
options = FormatOptions{};
},
'}' => {
if (start_index < i) {
try output(context, fmt[start_index..i]);
}
state = .CloseBrace;
},
else => {},
},
.Positional => switch (c) {
'{' => {
state = .Start;
start_index = i;
},
':' => {
state = if (comptime peekIsAlign(fmt[i..])) State.FormatFillAndAlign else State.FormatWidth;
specifier_end = i;
},
'0'...'9' => {
if (maybe_pos_arg == null) {
maybe_pos_arg = 0;
}
maybe_pos_arg.? *= 10;
maybe_pos_arg.? += c - '0';
specifier_start = i + 1;
if (maybe_pos_arg.? >= args.len) {
@compileError("Positional value refers to non-existent argument");
}
},
'}' => {
const arg_to_print = comptime nextArg(&used_pos_args, maybe_pos_arg, &next_arg);
if (arg_to_print >= args.len) {
@compileError("Too few arguments");
}
try formatType(
args[arg_to_print],
fmt[0..0],
options,
context,
Errors,
output,
default_max_depth,
);
state = .Start;
start_index = i + 1;
},
else => {
state = .Specifier;
specifier_start = i;
},
},
.CloseBrace => switch (c) {
'}' => {
state = .Start;
start_index = i;
},
else => @compileError("Single '}' encountered in format string"),
},
.Specifier => switch (c) {
':' => {
specifier_end = i;
state = if (comptime peekIsAlign(fmt[i..])) State.FormatFillAndAlign else State.FormatWidth;
},
'}' => {
const arg_to_print = comptime nextArg(&used_pos_args, maybe_pos_arg, &next_arg);
try formatType(
args[arg_to_print],
fmt[specifier_start..i],
options,
context,
Errors,
output,
default_max_depth,
);
state = .Start;
start_index = i + 1;
},
else => {},
},
// Only entered if the format string contains a fill/align segment.
.FormatFillAndAlign => switch (c) {
'<' => {
options.alignment = Alignment.Left;
state = .FormatWidth;
},
'^' => {
options.alignment = Alignment.Center;
state = .FormatWidth;
},
'>' => {
options.alignment = Alignment.Right;
state = .FormatWidth;
},
else => {
options.fill = c;
},
},
.FormatWidth => switch (c) {
'0'...'9' => {
if (options.width == null) {
options.width = 0;
}
options.width.? *= 10;
options.width.? += c - '0';
},
'.' => {
state = .FormatPrecision;
},
'}' => {
const arg_to_print = comptime nextArg(&used_pos_args, maybe_pos_arg, &next_arg);
try formatType(
args[arg_to_print],
fmt[specifier_start..specifier_end],
options,
context,
Errors,
output,
default_max_depth,
);
state = .Start;
start_index = i + 1;
},
else => {
@compileError("Unexpected character in width value: " ++ [_]u8{c});
},
},
.FormatPrecision => switch (c) {
'0'...'9' => {
if (options.precision == null) {
options.precision = 0;
}
options.precision.? *= 10;
options.precision.? += c - '0';
},
'}' => {
const arg_to_print = comptime nextArg(&used_pos_args, maybe_pos_arg, &next_arg);
try formatType(
args[arg_to_print],
fmt[specifier_start..specifier_end],
options,
context,
Errors,
output,
default_max_depth,
);
state = .Start;
start_index = i + 1;
},
else => {
@compileError("Unexpected character in precision value: " ++ [_]u8{c});
},
},
}
}
comptime {
// All arguments must have been printed but we allow mixing positional and fixed to achieve this.
var i: usize = 0;
inline while (i < next_arg) : (i += 1) {
used_pos_args |= 1 << i;
}
if (@popCount(ArgSetType, used_pos_args) != args.len) {
@compileError("Unused arguments");
}
if (state != State.Start) {
@compileError("Incomplete format string: " ++ fmt);
}
}
if (start_index < fmt.len) {
try output(context, fmt[start_index..]);
}
}
pub fn formatType(
value: var,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
max_depth: usize,
) Errors!void {
if (comptime std.mem.eql(u8, fmt, "*")) {
try output(context, @typeName(@typeOf(value).Child));
try output(context, "@");
try formatInt(@ptrToInt(value), 16, false, FormatOptions{}, context, Errors, output);
return;
}
const T = @typeOf(value);
switch (@typeInfo(T)) {
.ComptimeInt, .Int, .Float => {
return formatValue(value, fmt, options, context, Errors, output);
},
.Void => {
return output(context, "void");
},
.Bool => {
return output(context, if (value) "true" else "false");
},
.Optional => {
if (value) |payload| {
return formatType(payload, fmt, options, context, Errors, output, max_depth);
} else {
return output(context, "null");
}
},
.ErrorUnion => {
if (value) |payload| {
return formatType(payload, fmt, options, context, Errors, output, max_depth);
} else |err| {
return formatType(err, fmt, options, context, Errors, output, max_depth);
}
},
.ErrorSet => {
try output(context, "error.");
return output(context, @errorName(value));
},
.Enum => {
if (comptime std.meta.trait.hasFn("format")(T)) {
return value.format(fmt, options, context, Errors, output);
}
try output(context, @typeName(T));
try output(context, ".");
return formatType(@tagName(value), "", options, context, Errors, output, max_depth);
},
.Union => {
if (comptime std.meta.trait.hasFn("format")(T)) {
return value.format(fmt, options, context, Errors, output);
}
try output(context, @typeName(T));
if (max_depth == 0) {
return output(context, "{ ... }");
}
const info = @typeInfo(T).Union;
if (info.tag_type) |UnionTagType| {
try output(context, "{ .");
try output(context, @tagName(@as(UnionTagType, value)));
try output(context, " = ");
inline for (info.fields) |u_field| {
if (@enumToInt(@as(UnionTagType, value)) == u_field.enum_field.?.value) {
try formatType(@field(value, u_field.name), "", options, context, Errors, output, max_depth - 1);
}
}
try output(context, " }");
} else {
try format(context, Errors, output, "@{x}", @ptrToInt(&value));
}
},
.Struct => {
if (comptime std.meta.trait.hasFn("format")(T)) {
return value.format(fmt, options, context, Errors, output);
}
try output(context, @typeName(T));
if (max_depth == 0) {
return output(context, "{ ... }");
}
comptime var field_i = 0;
try output(context, "{");
inline while (field_i < @memberCount(T)) : (field_i += 1) {
if (field_i == 0) {
try output(context, " .");
} else {
try output(context, ", .");
}
try output(context, @memberName(T, field_i));
try output(context, " = ");
try formatType(@field(value, @memberName(T, field_i)), "", options, context, Errors, output, max_depth - 1);
}
try output(context, " }");
},
.Pointer => |ptr_info| switch (ptr_info.size) {
.One => switch (@typeInfo(ptr_info.child)) {
builtin.TypeId.Array => |info| {
if (info.child == u8) {
return formatText(value, fmt, options, context, Errors, output);
}
return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value));
},
builtin.TypeId.Enum, builtin.TypeId.Union, builtin.TypeId.Struct => {
return formatType(value.*, fmt, options, context, Errors, output, max_depth);
},
else => return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value)),
},
.Many => {
if (ptr_info.child == u8) {
if (fmt.len > 0 and fmt[0] == 's') {
const len = mem.len(u8, value);
return formatText(value[0..len], fmt, options, context, Errors, output);
}
}
return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value));
},
.Slice => {
if (fmt.len > 0 and ((fmt[0] == 'x') or (fmt[0] == 'X'))) {
return formatText(value, fmt, options, context, Errors, output);
}
if (ptr_info.child == u8) {
return formatText(value, fmt, options, context, Errors, output);
}
return format(context, Errors, output, "{}@{x}", @typeName(ptr_info.child), @ptrToInt(value.ptr));
},
.C => {
return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value));
},
},
.Array => |info| {
const Slice = @Type(builtin.TypeInfo{
.Pointer = .{
.size = .Slice,
.is_const = true,
.is_volatile = false,
.is_allowzero = false,
.alignment = @alignOf(info.child),
.child = info.child,
.sentinel = null,
},
});
return formatType(@as(Slice, &value), fmt, options, context, Errors, output, max_depth);
},
.Fn => {
return format(context, Errors, output, "{}@{x}", @typeName(T), @ptrToInt(value));
},
else => @compileError("Unable to format type '" ++ @typeName(T) ++ "'"),
}
}
fn formatValue(
value: var,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (comptime std.mem.eql(u8, fmt, "B")) {
return formatBytes(value, options, 1000, context, Errors, output);
} else if (comptime std.mem.eql(u8, fmt, "Bi")) {
return formatBytes(value, options, 1024, context, Errors, output);
}
const T = @typeOf(value);
switch (@typeId(T)) {
.Float => return formatFloatValue(value, fmt, options, context, Errors, output),
.Int, .ComptimeInt => return formatIntValue(value, fmt, options, context, Errors, output),
else => comptime unreachable,
}
}
pub fn formatIntValue(
value: var,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
comptime var radix = 10;
comptime var uppercase = false;
const int_value = if (@typeOf(value) == comptime_int) blk: {
const Int = math.IntFittingRange(value, value);
break :blk @as(Int, value);
} else
value;
if (fmt.len == 0 or comptime std.mem.eql(u8, fmt, "d")) {
radix = 10;
uppercase = false;
} else if (comptime std.mem.eql(u8, fmt, "c")) {
if (@typeOf(int_value).bit_count <= 8) {
return formatAsciiChar(@as(u8, int_value), options, context, Errors, output);
} else {
@compileError("Cannot print integer that is larger than 8 bits as a ascii");
}
} else if (comptime std.mem.eql(u8, fmt, "b")) {
radix = 2;
uppercase = false;
} else if (comptime std.mem.eql(u8, fmt, "x")) {
radix = 16;
uppercase = false;
} else if (comptime std.mem.eql(u8, fmt, "X")) {
radix = 16;
uppercase = true;
} else {
@compileError("Unknown format string: '" ++ fmt ++ "'");
}
return formatInt(int_value, radix, uppercase, options, context, Errors, output);
}
fn formatFloatValue(
value: var,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (fmt.len == 0 or comptime std.mem.eql(u8, fmt, "e")) {
return formatFloatScientific(value, options, context, Errors, output);
} else if (comptime std.mem.eql(u8, fmt, "d")) {
return formatFloatDecimal(value, options, context, Errors, output);
} else {
@compileError("Unknown format string: '" ++ fmt ++ "'");
}
}
pub fn formatText(
bytes: []const u8,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (fmt.len == 0) {
return output(context, bytes);
} else if (comptime std.mem.eql(u8, fmt, "s")) {
return formatBuf(bytes, options, context, Errors, output);
} else if (comptime (std.mem.eql(u8, fmt, "x") or std.mem.eql(u8, fmt, "X"))) {
for (bytes) |c| {
try formatInt(c, 16, fmt[0] == 'X', FormatOptions{ .width = 2, .fill = '0' }, context, Errors, output);
}
return;
} else {
@compileError("Unknown format string: '" ++ fmt ++ "'");
}
}
pub fn formatAsciiChar(
c: u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
return output(context, @as(*const [1]u8, &c)[0..]);
}
pub fn formatBuf(
buf: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
try output(context, buf);
const width = options.width orelse 0;
var leftover_padding = if (width > buf.len) (width - buf.len) else return;
const pad_byte: u8 = options.fill;
while (leftover_padding > 0) : (leftover_padding -= 1) {
try output(context, @as(*const [1]u8, &pad_byte)[0..1]);
}
}
// Print a float in scientific notation to the specified precision. Null uses full precision.
// It should be the case that every full precision, printed value can be re-parsed back to the
// same type unambiguously.
pub fn formatFloatScientific(
value: var,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
var x = @floatCast(f64, value);
// Errol doesn't handle these special cases.
if (math.signbit(x)) {
try output(context, "-");
x = -x;
}
if (math.isNan(x)) {
return output(context, "nan");
}
if (math.isPositiveInf(x)) {
return output(context, "inf");
}
if (x == 0.0) {
try output(context, "0");
if (options.precision) |precision| {
if (precision != 0) {
try output(context, ".");
var i: usize = 0;
while (i < precision) : (i += 1) {
try output(context, "0");
}
}
} else {
try output(context, ".0");
}
try output(context, "e+00");
return;
}
var buffer: [32]u8 = undefined;
var float_decimal = errol.errol3(x, buffer[0..]);
if (options.precision) |precision| {
errol.roundToPrecision(&float_decimal, precision, errol.RoundMode.Scientific);
try output(context, float_decimal.digits[0..1]);
// {e0} case prints no `.`
if (precision != 0) {
try output(context, ".");
var printed: usize = 0;
if (float_decimal.digits.len > 1) {
const num_digits = math.min(float_decimal.digits.len, precision + 1);
try output(context, float_decimal.digits[1..num_digits]);
printed += num_digits - 1;
}
while (printed < precision) : (printed += 1) {
try output(context, "0");
}
}
} else {
try output(context, float_decimal.digits[0..1]);
try output(context, ".");
if (float_decimal.digits.len > 1) {
const num_digits = if (@typeOf(value) == f32) math.min(@as(usize, 9), float_decimal.digits.len) else float_decimal.digits.len;
try output(context, float_decimal.digits[1..num_digits]);
} else {
try output(context, "0");
}
}
try output(context, "e");
const exp = float_decimal.exp - 1;
if (exp >= 0) {
try output(context, "+");
if (exp > -10 and exp < 10) {
try output(context, "0");
}
try formatInt(exp, 10, false, FormatOptions{ .width = 0 }, context, Errors, output);
} else {
try output(context, "-");
if (exp > -10 and exp < 10) {
try output(context, "0");
}
try formatInt(-exp, 10, false, FormatOptions{ .width = 0 }, context, Errors, output);
}
}
// Print a float of the format x.yyyyy where the number of y is specified by the precision argument.
// By default floats are printed at full precision (no rounding).
pub fn formatFloatDecimal(
value: var,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
var x = @as(f64, value);
// Errol doesn't handle these special cases.
if (math.signbit(x)) {
try output(context, "-");
x = -x;
}
if (math.isNan(x)) {
return output(context, "nan");
}
if (math.isPositiveInf(x)) {
return output(context, "inf");
}
if (x == 0.0) {
try output(context, "0");
if (options.precision) |precision| {
if (precision != 0) {
try output(context, ".");
var i: usize = 0;
while (i < precision) : (i += 1) {
try output(context, "0");
}
} else {
try output(context, ".0");
}
} else {
try output(context, "0");
}
return;
}
// non-special case, use errol3
var buffer: [32]u8 = undefined;
var float_decimal = errol.errol3(x, buffer[0..]);
if (options.precision) |precision| {
errol.roundToPrecision(&float_decimal, precision, errol.RoundMode.Decimal);
// exp < 0 means the leading is always 0 as errol result is normalized.
var num_digits_whole = if (float_decimal.exp > 0) @intCast(usize, float_decimal.exp) else 0;
// the actual slice into the buffer, we may need to zero-pad between num_digits_whole and this.
var num_digits_whole_no_pad = math.min(num_digits_whole, float_decimal.digits.len);
if (num_digits_whole > 0) {
// We may have to zero pad, for instance 1e4 requires zero padding.
try output(context, float_decimal.digits[0..num_digits_whole_no_pad]);
var i = num_digits_whole_no_pad;
while (i < num_digits_whole) : (i += 1) {
try output(context, "0");
}
} else {
try output(context, "0");
}
// {.0} special case doesn't want a trailing '.'
if (precision == 0) {
return;
}
try output(context, ".");
// Keep track of fractional count printed for case where we pre-pad then post-pad with 0's.
var printed: usize = 0;
// Zero-fill until we reach significant digits or run out of precision.
if (float_decimal.exp <= 0) {
const zero_digit_count = @intCast(usize, -float_decimal.exp);
const zeros_to_print = math.min(zero_digit_count, precision);
var i: usize = 0;
while (i < zeros_to_print) : (i += 1) {
try output(context, "0");
printed += 1;
}
if (printed >= precision) {
return;
}
}
// Remaining fractional portion, zero-padding if insufficient.
assert(precision >= printed);
if (num_digits_whole_no_pad + precision - printed < float_decimal.digits.len) {
try output(context, float_decimal.digits[num_digits_whole_no_pad .. num_digits_whole_no_pad + precision - printed]);
return;
} else {
try output(context, float_decimal.digits[num_digits_whole_no_pad..]);
printed += float_decimal.digits.len - num_digits_whole_no_pad;
while (printed < precision) : (printed += 1) {
try output(context, "0");
}
}
} else {
// exp < 0 means the leading is always 0 as errol result is normalized.
var num_digits_whole = if (float_decimal.exp > 0) @intCast(usize, float_decimal.exp) else 0;
// the actual slice into the buffer, we may need to zero-pad between num_digits_whole and this.
var num_digits_whole_no_pad = math.min(num_digits_whole, float_decimal.digits.len);
if (num_digits_whole > 0) {
// We may have to zero pad, for instance 1e4 requires zero padding.
try output(context, float_decimal.digits[0..num_digits_whole_no_pad]);
var i = num_digits_whole_no_pad;
while (i < num_digits_whole) : (i += 1) {
try output(context, "0");
}
} else {
try output(context, "0");
}
// Omit `.` if no fractional portion
if (float_decimal.exp >= 0 and num_digits_whole_no_pad == float_decimal.digits.len) {
return;
}
try output(context, ".");
// Zero-fill until we reach significant digits or run out of precision.
if (float_decimal.exp < 0) {
const zero_digit_count = @intCast(usize, -float_decimal.exp);
var i: usize = 0;
while (i < zero_digit_count) : (i += 1) {
try output(context, "0");
}
}
try output(context, float_decimal.digits[num_digits_whole_no_pad..]);
}
}
pub fn formatBytes(
value: var,
options: FormatOptions,
comptime radix: usize,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (value == 0) {
return output(context, "0B");
}
const mags_si = " kMGTPEZY";
const mags_iec = " KMGTPEZY";
const magnitude = switch (radix) {
1000 => math.min(math.log2(value) / comptime math.log2(1000), mags_si.len - 1),
1024 => math.min(math.log2(value) / 10, mags_iec.len - 1),
else => unreachable,
};
const new_value = lossyCast(f64, value) / math.pow(f64, lossyCast(f64, radix), lossyCast(f64, magnitude));
const suffix = switch (radix) {
1000 => mags_si[magnitude],
1024 => mags_iec[magnitude],
else => unreachable,
};
try formatFloatDecimal(new_value, options, context, Errors, output);
if (suffix == ' ') {
return output(context, "B");
}
const buf = switch (radix) {
1000 => &[_]u8{ suffix, 'B' },
1024 => &[_]u8{ suffix, 'i', 'B' },
else => unreachable,
};
return output(context, buf);
}
pub fn formatInt(
value: var,
base: u8,
uppercase: bool,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
const int_value = if (@typeOf(value) == comptime_int) blk: {
const Int = math.IntFittingRange(value, value);
break :blk @as(Int, value);
} else
value;
if (@typeOf(int_value).is_signed) {
return formatIntSigned(int_value, base, uppercase, options, context, Errors, output);
} else {
return formatIntUnsigned(int_value, base, uppercase, options, context, Errors, output);
}
}
fn formatIntSigned(
value: var,
base: u8,
uppercase: bool,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
const new_options = FormatOptions{
.width = if (options.width) |w| (if (w == 0) 0 else w - 1) else null,
.precision = options.precision,
.fill = options.fill,
};
const uint = @IntType(false, @typeOf(value).bit_count);
if (value < 0) {
const minus_sign: u8 = '-';
try output(context, @as(*const [1]u8, &minus_sign)[0..]);
const new_value = @intCast(uint, -(value + 1)) + 1;
return formatIntUnsigned(new_value, base, uppercase, new_options, context, Errors, output);
} else if (options.width == null or options.width.? == 0) {
return formatIntUnsigned(@intCast(uint, value), base, uppercase, options, context, Errors, output);
} else {
const plus_sign: u8 = '+';
try output(context, @as(*const [1]u8, &plus_sign)[0..]);
const new_value = @intCast(uint, value);
return formatIntUnsigned(new_value, base, uppercase, new_options, context, Errors, output);
}
}
fn formatIntUnsigned(
value: var,
base: u8,
uppercase: bool,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
assert(base >= 2);
var buf: [math.max(@typeOf(value).bit_count, 1)]u8 = undefined;
const min_int_bits = comptime math.max(@typeOf(value).bit_count, @typeOf(base).bit_count);
const MinInt = @IntType(@typeOf(value).is_signed, min_int_bits);
var a: MinInt = value;
var index: usize = buf.len;
while (true) {
const digit = a % base;
index -= 1;
buf[index] = digitToChar(@intCast(u8, digit), uppercase);
a /= base;
if (a == 0) break;
}
const digits_buf = buf[index..];
const width = options.width orelse 0;
const padding = if (width > digits_buf.len) (width - digits_buf.len) else 0;
if (padding > index) {
const zero_byte: u8 = options.fill;
var leftover_padding = padding - index;
while (true) {
try output(context, @as(*const [1]u8, &zero_byte)[0..]);
leftover_padding -= 1;
if (leftover_padding == 0) break;
}
mem.set(u8, buf[0..index], options.fill);
return output(context, &buf);
} else {
const padded_buf = buf[index - padding ..];
mem.set(u8, padded_buf[0..padding], options.fill);
return output(context, padded_buf);
}
}
pub fn formatIntBuf(out_buf: []u8, value: var, base: u8, uppercase: bool, options: FormatOptions) usize {
var context = FormatIntBuf{
.out_buf = out_buf,
.index = 0,
};
formatInt(value, base, uppercase, options, &context, error{}, formatIntCallback) catch unreachable;
return context.index;
}
const FormatIntBuf = struct {
out_buf: []u8,
index: usize,
};
fn formatIntCallback(context: *FormatIntBuf, bytes: []const u8) (error{}!void) {
mem.copy(u8, context.out_buf[context.index..], bytes);
context.index += bytes.len;
}
pub fn parseInt(comptime T: type, buf: []const u8, radix: u8) !T {
if (!T.is_signed) return parseUnsigned(T, buf, radix);
if (buf.len == 0) return @as(T, 0);
if (buf[0] == '-') {
return math.negate(try parseUnsigned(T, buf[1..], radix));
} else if (buf[0] == '+') {
return parseUnsigned(T, buf[1..], radix);
} else {
return parseUnsigned(T, buf, radix);
}
}
test "parseInt" {
std.testing.expect((parseInt(i32, "-10", 10) catch unreachable) == -10);
std.testing.expect((parseInt(i32, "+10", 10) catch unreachable) == 10);
std.testing.expect(if (parseInt(i32, " 10", 10)) |_| false else |err| err == error.InvalidCharacter);
std.testing.expect(if (parseInt(i32, "10 ", 10)) |_| false else |err| err == error.InvalidCharacter);
std.testing.expect(if (parseInt(u32, "-10", 10)) |_| false else |err| err == error.InvalidCharacter);
std.testing.expect((parseInt(u8, "255", 10) catch unreachable) == 255);
std.testing.expect(if (parseInt(u8, "256", 10)) |_| false else |err| err == error.Overflow);
}
const ParseUnsignedError = error{
/// The result cannot fit in the type specified
Overflow,
/// The input had a byte that was not a digit
InvalidCharacter,
};
pub fn parseUnsigned(comptime T: type, buf: []const u8, radix: u8) ParseUnsignedError!T {
var x: T = 0;
for (buf) |c| {
const digit = try charToDigit(c, radix);
if (x != 0) x = try math.mul(T, x, try math.cast(T, radix));
x = try math.add(T, x, try math.cast(T, digit));
}
return x;
}
test "parseUnsigned" {
std.testing.expect((try parseUnsigned(u16, "050124", 10)) == 50124);
std.testing.expect((try parseUnsigned(u16, "65535", 10)) == 65535);
std.testing.expectError(error.Overflow, parseUnsigned(u16, "65536", 10));
std.testing.expect((try parseUnsigned(u64, "0ffffffffffffffff", 16)) == 0xffffffffffffffff);
std.testing.expectError(error.Overflow, parseUnsigned(u64, "10000000000000000", 16));
std.testing.expect((try parseUnsigned(u32, "DeadBeef", 16)) == 0xDEADBEEF);
std.testing.expect((try parseUnsigned(u7, "1", 10)) == 1);
std.testing.expect((try parseUnsigned(u7, "1000", 2)) == 8);
std.testing.expectError(error.InvalidCharacter, parseUnsigned(u32, "f", 10));
std.testing.expectError(error.InvalidCharacter, parseUnsigned(u8, "109", 8));
std.testing.expect((try parseUnsigned(u32, "NUMBER", 36)) == 1442151747);
// these numbers should fit even though the radix itself doesn't fit in the destination type
std.testing.expect((try parseUnsigned(u1, "0", 10)) == 0);
std.testing.expect((try parseUnsigned(u1, "1", 10)) == 1);
std.testing.expectError(error.Overflow, parseUnsigned(u1, "2", 10));
std.testing.expect((try parseUnsigned(u1, "001", 16)) == 1);
std.testing.expect((try parseUnsigned(u2, "3", 16)) == 3);
std.testing.expectError(error.Overflow, parseUnsigned(u2, "4", 16));
}
pub const parseFloat = @import("fmt/parse_float.zig").parseFloat;
test "parseFloat" {
_ = @import("fmt/parse_float.zig");
}
pub fn charToDigit(c: u8, radix: u8) (error{InvalidCharacter}!u8) {
const value = switch (c) {
'0'...'9' => c - '0',
'A'...'Z' => c - 'A' + 10,
'a'...'z' => c - 'a' + 10,
else => return error.InvalidCharacter,
};
if (value >= radix) return error.InvalidCharacter;
return value;
}
fn digitToChar(digit: u8, uppercase: bool) u8 {
return switch (digit) {
0...9 => digit + '0',
10...35 => digit + ((if (uppercase) @as(u8, 'A') else @as(u8, 'a')) - 10),
else => unreachable,
};
}
const BufPrintContext = struct {
remaining: []u8,
};
fn bufPrintWrite(context: *BufPrintContext, bytes: []const u8) !void {
if (context.remaining.len < bytes.len) {
mem.copy(u8, context.remaining, bytes[0..context.remaining.len]);
return error.BufferTooSmall;
}
mem.copy(u8, context.remaining, bytes);
context.remaining = context.remaining[bytes.len..];
}
pub const BufPrintError = error{
/// As much as possible was written to the buffer, but it was too small to fit all the printed bytes.
BufferTooSmall,
};
pub fn bufPrint(buf: []u8, comptime fmt: []const u8, args: ...) BufPrintError![]u8 {
var context = BufPrintContext{ .remaining = buf };
try format(&context, BufPrintError, bufPrintWrite, fmt, args);
return buf[0 .. buf.len - context.remaining.len];
}
pub const AllocPrintError = error{OutOfMemory};
pub fn allocPrint(allocator: *mem.Allocator, comptime fmt: []const u8, args: ...) AllocPrintError![]u8 {
var size: usize = 0;
format(&size, error{}, countSize, fmt, args) catch |err| switch (err) {};
const buf = try allocator.alloc(u8, size);
return bufPrint(buf, fmt, args) catch |err| switch (err) {
error.BufferTooSmall => unreachable, // we just counted the size above
};
}
fn countSize(size: *usize, bytes: []const u8) (error{}!void) {
size.* += bytes.len;
}
test "bufPrintInt" {
var buffer: [100]u8 = undefined;
const buf = buffer[0..];
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(i32, -12345678), 2, false, FormatOptions{}), "-101111000110000101001110"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(i32, -12345678), 10, false, FormatOptions{}), "-12345678"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(i32, -12345678), 16, false, FormatOptions{}), "-bc614e"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(i32, -12345678), 16, true, FormatOptions{}), "-BC614E"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(u32, 12345678), 10, true, FormatOptions{}), "12345678"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(u32, 666), 10, false, FormatOptions{ .width = 6 }), " 666"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(u32, 0x1234), 16, false, FormatOptions{ .width = 6 }), " 1234"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(u32, 0x1234), 16, false, FormatOptions{ .width = 1 }), "1234"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(i32, 42), 10, false, FormatOptions{ .width = 3 }), "+42"));
std.testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, @as(i32, -42), 10, false, FormatOptions{ .width = 3 }), "-42"));
}
fn bufPrintIntToSlice(buf: []u8, value: var, base: u8, uppercase: bool, options: FormatOptions) []u8 {
return buf[0..formatIntBuf(buf, value, base, uppercase, options)];
}
test "parse u64 digit too big" {
_ = parseUnsigned(u64, "123a", 10) catch |err| {
if (err == error.InvalidCharacter) return;
unreachable;
};
unreachable;
}
test "parse unsigned comptime" {
comptime {
std.testing.expect((try parseUnsigned(usize, "2", 10)) == 2);
}
}
test "optional" {
{
const value: ?i32 = 1234;
try testFmt("optional: 1234\n", "optional: {}\n", value);
}
{
const value: ?i32 = null;
try testFmt("optional: null\n", "optional: {}\n", value);
}
}
test "error" {
{
const value: anyerror!i32 = 1234;
try testFmt("error union: 1234\n", "error union: {}\n", value);
}
{
const value: anyerror!i32 = error.InvalidChar;
try testFmt("error union: error.InvalidChar\n", "error union: {}\n", value);
}
}
test "int.small" {
{
const value: u3 = 0b101;
try testFmt("u3: 5\n", "u3: {}\n", value);
}
}
test "int.specifier" {
{
const value: u8 = 'a';
try testFmt("u8: a\n", "u8: {c}\n", value);
}
{
const value: u8 = 0b1100;
try testFmt("u8: 0b1100\n", "u8: 0b{b}\n", value);
}
}
test "int.padded" {
try testFmt("u8: ' 1'", "u8: '{:4}'", @as(u8, 1));
try testFmt("u8: 'xxx1'", "u8: '{:x<4}'", @as(u8, 1));
}
test "buffer" {
{
var buf1: [32]u8 = undefined;
var context = BufPrintContext{ .remaining = buf1[0..] };
try formatType(1234, "", FormatOptions{}, &context, error{BufferTooSmall}, bufPrintWrite, default_max_depth);
var res = buf1[0 .. buf1.len - context.remaining.len];
std.testing.expect(mem.eql(u8, res, "1234"));
context = BufPrintContext{ .remaining = buf1[0..] };
try formatType('a', "c", FormatOptions{}, &context, error{BufferTooSmall}, bufPrintWrite, default_max_depth);
res = buf1[0 .. buf1.len - context.remaining.len];
std.testing.expect(mem.eql(u8, res, "a"));
context = BufPrintContext{ .remaining = buf1[0..] };
try formatType(0b1100, "b", FormatOptions{}, &context, error{BufferTooSmall}, bufPrintWrite, default_max_depth);
res = buf1[0 .. buf1.len - context.remaining.len];
std.testing.expect(mem.eql(u8, res, "1100"));
}
}
test "array" {
{
const value: [3]u8 = "abc".*;
try testFmt("array: abc\n", "array: {}\n", value);
try testFmt("array: abc\n", "array: {}\n", &value);
var buf: [100]u8 = undefined;
try testFmt(
try bufPrint(buf[0..], "array: [3]u8@{x}\n", @ptrToInt(&value)),
"array: {*}\n",
&value,
);
}
}
test "slice" {
{
const value: []const u8 = "abc";
try testFmt("slice: abc\n", "slice: {}\n", value);
}
{
const value = @intToPtr([*]const []const u8, 0xdeadbeef)[0..0];
try testFmt("slice: []const u8@deadbeef\n", "slice: {}\n", value);
}
try testFmt("buf: Test \n", "buf: {s:5}\n", "Test");
try testFmt("buf: Test\n Other text", "buf: {s}\n Other text", "Test");
}
test "pointer" {
{
const value = @intToPtr(*i32, 0xdeadbeef);
try testFmt("pointer: i32@deadbeef\n", "pointer: {}\n", value);
try testFmt("pointer: i32@deadbeef\n", "pointer: {*}\n", value);
}
{
const value = @intToPtr(fn () void, 0xdeadbeef);
try testFmt("pointer: fn() void@deadbeef\n", "pointer: {}\n", value);
}
{
const value = @intToPtr(fn () void, 0xdeadbeef);
try testFmt("pointer: fn() void@deadbeef\n", "pointer: {}\n", value);
}
}
test "cstr" {
try testFmt("cstr: Test C\n", "cstr: {s}\n", "Test C");
try testFmt("cstr: Test C \n", "cstr: {s:10}\n", "Test C");
}
test "filesize" {
if (builtin.os == .linux and builtin.arch == .arm and builtin.abi == .musleabihf) {
// TODO https://github.com/ziglang/zig/issues/3289
return error.SkipZigTest;
}
try testFmt("file size: 63MiB\n", "file size: {Bi}\n", @as(usize, 63 * 1024 * 1024));
try testFmt("file size: 66.06MB\n", "file size: {B:.2}\n", @as(usize, 63 * 1024 * 1024));
}
test "struct" {
{
const Struct = struct {
field: u8,
};
const value = Struct{ .field = 42 };
try testFmt("struct: Struct{ .field = 42 }\n", "struct: {}\n", value);
try testFmt("struct: Struct{ .field = 42 }\n", "struct: {}\n", &value);
}
{
const Struct = struct {
a: u0,
b: u1,
};
const value = Struct{ .a = 0, .b = 1 };
try testFmt("struct: Struct{ .a = 0, .b = 1 }\n", "struct: {}\n", value);
}
}
test "enum" {
const Enum = enum {
One,
Two,
};
const value = Enum.Two;
try testFmt("enum: Enum.Two\n", "enum: {}\n", value);
try testFmt("enum: Enum.Two\n", "enum: {}\n", &value);
}
test "float.scientific" {
if (builtin.os == .linux and builtin.arch == .arm and builtin.abi == .musleabihf) {
// TODO https://github.com/ziglang/zig/issues/3289
return error.SkipZigTest;
}
try testFmt("f32: 1.34000003e+00", "f32: {e}", @as(f32, 1.34));
try testFmt("f32: 1.23400001e+01", "f32: {e}", @as(f32, 12.34));
try testFmt("f64: -1.234e+11", "f64: {e}", @as(f64, -12.34e10));
try testFmt("f64: 9.99996e-40", "f64: {e}", @as(f64, 9.999960e-40));
}
test "float.scientific.precision" {
if (builtin.os == .linux and builtin.arch == .arm and builtin.abi == .musleabihf) {
// TODO https://github.com/ziglang/zig/issues/3289
return error.SkipZigTest;
}
try testFmt("f64: 1.40971e-42", "f64: {e:.5}", @as(f64, 1.409706e-42));
try testFmt("f64: 1.00000e-09", "f64: {e:.5}", @as(f64, @bitCast(f32, @as(u32, 814313563))));
try testFmt("f64: 7.81250e-03", "f64: {e:.5}", @as(f64, @bitCast(f32, @as(u32, 1006632960))));
// libc rounds 1.000005e+05 to 1.00000e+05 but zig does 1.00001e+05.
// In fact, libc doesn't round a lot of 5 cases up when one past the precision point.
try testFmt("f64: 1.00001e+05", "f64: {e:.5}", @as(f64, @bitCast(f32, @as(u32, 1203982400))));
}
test "float.special" {
if (builtin.os == .linux and builtin.arch == .arm and builtin.abi == .musleabihf) {
// TODO https://github.com/ziglang/zig/issues/3289
return error.SkipZigTest;
}
try testFmt("f64: nan", "f64: {}", math.nan_f64);
// negative nan is not defined by IEE 754,
// and ARM thus normalizes it to positive nan
if (builtin.arch != builtin.Arch.arm) {
try testFmt("f64: -nan", "f64: {}", -math.nan_f64);
}
try testFmt("f64: inf", "f64: {}", math.inf_f64);
try testFmt("f64: -inf", "f64: {}", -math.inf_f64);
}
test "float.decimal" {
if (builtin.os == .linux and builtin.arch == .arm and builtin.abi == .musleabihf) {
// TODO https://github.com/ziglang/zig/issues/3289
return error.SkipZigTest;
}
try testFmt("f64: 152314000000000000000000000000", "f64: {d}", @as(f64, 1.52314e+29));
try testFmt("f32: 1.1", "f32: {d:.1}", @as(f32, 1.1234));
try testFmt("f32: 1234.57", "f32: {d:.2}", @as(f32, 1234.567));
// -11.1234 is converted to f64 -11.12339... internally (errol3() function takes f64).
// -11.12339... is rounded back up to -11.1234
try testFmt("f32: -11.1234", "f32: {d:.4}", @as(f32, -11.1234));
try testFmt("f32: 91.12345", "f32: {d:.5}", @as(f32, 91.12345));
try testFmt("f64: 91.1234567890", "f64: {d:.10}", @as(f64, 91.12345678901235));
try testFmt("f64: 0.00000", "f64: {d:.5}", @as(f64, 0.0));
try testFmt("f64: 6", "f64: {d:.0}", @as(f64, 5.700));
try testFmt("f64: 10.0", "f64: {d:.1}", @as(f64, 9.999));
try testFmt("f64: 1.000", "f64: {d:.3}", @as(f64, 1.0));
try testFmt("f64: 0.00030000", "f64: {d:.8}", @as(f64, 0.0003));
try testFmt("f64: 0.00000", "f64: {d:.5}", @as(f64, 1.40130e-45));
try testFmt("f64: 0.00000", "f64: {d:.5}", @as(f64, 9.999960e-40));
}
test "float.libc.sanity" {
if (builtin.os == .linux and builtin.arch == .arm and builtin.abi == .musleabihf) {
// TODO https://github.com/ziglang/zig/issues/3289
return error.SkipZigTest;
}
try testFmt("f64: 0.00001", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 916964781))));
try testFmt("f64: 0.00001", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 925353389))));
try testFmt("f64: 0.10000", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 1036831278))));
try testFmt("f64: 1.00000", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 1065353133))));
try testFmt("f64: 10.00000", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 1092616192))));
// libc differences
//
// This is 0.015625 exactly according to gdb. We thus round down,
// however glibc rounds up for some reason. This occurs for all
// floats of the form x.yyyy25 on a precision point.
try testFmt("f64: 0.01563", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 1015021568))));
// errol3 rounds to ... 630 but libc rounds to ...632. Grisu3
// also rounds to 630 so I'm inclined to believe libc is not
// optimal here.
try testFmt("f64: 18014400656965630.00000", "f64: {d:.5}", @as(f64, @bitCast(f32, @as(u32, 1518338049))));
}
test "custom" {
const Vec2 = struct {
const SelfType = @This();
x: f32,
y: f32,
pub fn format(
self: SelfType,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (fmt.len == 0 or comptime std.mem.eql(u8, fmt, "p")) {
return std.fmt.format(context, Errors, output, "({d:.3},{d:.3})", self.x, self.y);
} else if (comptime std.mem.eql(u8, fmt, "d")) {
return std.fmt.format(context, Errors, output, "{d:.3}x{d:.3}", self.x, self.y);
} else {
@compileError("Unknown format character: '" ++ fmt ++ "'");
}
}
};
var buf1: [32]u8 = undefined;
var value = Vec2{
.x = 10.2,
.y = 2.22,
};
try testFmt("point: (10.200,2.220)\n", "point: {}\n", &value);
try testFmt("dim: 10.200x2.220\n", "dim: {d}\n", &value);
// same thing but not passing a pointer
try testFmt("point: (10.200,2.220)\n", "point: {}\n", value);
try testFmt("dim: 10.200x2.220\n", "dim: {d}\n", value);
}
test "struct" {
const S = struct {
a: u32,
b: anyerror,
};
const inst = S{
.a = 456,
.b = error.Unused,
};
try testFmt("S{ .a = 456, .b = error.Unused }", "{}", inst);
}
test "union" {
const TU = union(enum) {
float: f32,
int: u32,
};
const UU = union {
float: f32,
int: u32,
};
const EU = extern union {
float: f32,
int: u32,
};
const tu_inst = TU{ .int = 123 };
const uu_inst = UU{ .int = 456 };
const eu_inst = EU{ .float = 321.123 };
try testFmt("TU{ .int = 123 }", "{}", tu_inst);
var buf: [100]u8 = undefined;
const uu_result = try bufPrint(buf[0..], "{}", uu_inst);
std.testing.expect(mem.eql(u8, uu_result[0..3], "UU@"));
const eu_result = try bufPrint(buf[0..], "{}", eu_inst);
std.testing.expect(mem.eql(u8, uu_result[0..3], "EU@"));
}
test "enum" {
const E = enum {
One,
Two,
Three,
};
const inst = E.Two;
try testFmt("E.Two", "{}", inst);
}
test "struct.self-referential" {
const S = struct {
const SelfType = @This();
a: ?*SelfType,
};
var inst = S{
.a = null,
};
inst.a = &inst;
try testFmt("S{ .a = S{ .a = S{ .a = S{ ... } } } }", "{}", inst);
}
test "struct.zero-size" {
const A = struct {
fn foo() void {}
};
const B = struct {
a: A,
c: i32,
};
const a = A{};
const b = B{ .a = a, .c = 0 };
try testFmt("B{ .a = A{ }, .c = 0 }", "{}", b);
}
test "bytes.hex" {
const some_bytes = "\xCA\xFE\xBA\xBE";
try testFmt("lowercase: cafebabe\n", "lowercase: {x}\n", some_bytes);
try testFmt("uppercase: CAFEBABE\n", "uppercase: {X}\n", some_bytes);
//Test Slices
try testFmt("uppercase: CAFE\n", "uppercase: {X}\n", some_bytes[0..2]);
try testFmt("lowercase: babe\n", "lowercase: {x}\n", some_bytes[2..]);
const bytes_with_zeros = "\x00\x0E\xBA\xBE";
try testFmt("lowercase: 000ebabe\n", "lowercase: {x}\n", bytes_with_zeros);
}
fn testFmt(expected: []const u8, comptime template: []const u8, args: ...) !void {
var buf: [100]u8 = undefined;
const result = try bufPrint(buf[0..], template, args);
if (mem.eql(u8, result, expected)) return;
std.debug.warn("\n====== expected this output: =========\n");
std.debug.warn("{}", expected);
std.debug.warn("\n======== instead found this: =========\n");
std.debug.warn("{}", result);
std.debug.warn("\n======================================\n");
return error.TestFailed;
}
pub fn trim(buf: []const u8) []const u8 {
var start: usize = 0;
while (start < buf.len and isWhiteSpace(buf[start])) : (start += 1) {}
var end: usize = buf.len;
while (true) {
if (end > start) {
const new_end = end - 1;
if (isWhiteSpace(buf[new_end])) {
end = new_end;
continue;
}
}
break;
}
return buf[start..end];
}
test "trim" {
std.testing.expect(mem.eql(u8, "abc", trim("\n abc \t")));
std.testing.expect(mem.eql(u8, "", trim(" ")));
std.testing.expect(mem.eql(u8, "", trim("")));
std.testing.expect(mem.eql(u8, "abc", trim(" abc")));
std.testing.expect(mem.eql(u8, "abc", trim("abc ")));
}
pub fn isWhiteSpace(byte: u8) bool {
return switch (byte) {
' ', '\t', '\n', '\r' => true,
else => false,
};
}
pub fn hexToBytes(out: []u8, input: []const u8) !void {
if (out.len * 2 < input.len)
return error.InvalidLength;
var in_i: usize = 0;
while (in_i != input.len) : (in_i += 2) {
const hi = try charToDigit(input[in_i], 16);
const lo = try charToDigit(input[in_i + 1], 16);
out[in_i / 2] = (hi << 4) | lo;
}
}
test "hexToBytes" {
const test_hex_str = "909A312BB12ED1F819B3521AC4C1E896F2160507FFC1C8381E3B07BB16BD1706";
var pb: [32]u8 = undefined;
try hexToBytes(pb[0..], test_hex_str);
try testFmt(test_hex_str, "{X}", pb);
}
test "formatIntValue with comptime_int" {
const value: comptime_int = 123456789123456789;
var buf = try std.Buffer.init(std.debug.global_allocator, "");
try formatIntValue(value, "", FormatOptions{}, &buf, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append);
std.testing.expect(mem.eql(u8, buf.toSlice(), "123456789123456789"));
}
test "formatType max_depth" {
const Vec2 = struct {
const SelfType = @This();
x: f32,
y: f32,
pub fn format(
self: SelfType,
comptime fmt: []const u8,
options: FormatOptions,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (fmt.len == 0) {
return std.fmt.format(context, Errors, output, "({d:.3},{d:.3})", self.x, self.y);
} else {
@compileError("Unknown format string: '" ++ fmt ++ "'");
}
}
};
const E = enum {
One,
Two,
Three,
};
const TU = union(enum) {
const SelfType = @This();
float: f32,
int: u32,
ptr: ?*SelfType,
};
const S = struct {
const SelfType = @This();
a: ?*SelfType,
tu: TU,
e: E,
vec: Vec2,
};
var inst = S{
.a = null,
.tu = TU{ .ptr = null },
.e = E.Two,
.vec = Vec2{ .x = 10.2, .y = 2.22 },
};
inst.a = &inst;
inst.tu.ptr = &inst.tu;
var buf0 = try std.Buffer.init(std.debug.global_allocator, "");
try formatType(inst, "", FormatOptions{}, &buf0, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 0);
std.testing.expect(mem.eql(u8, buf0.toSlice(), "S{ ... }"));
var buf1 = try std.Buffer.init(std.debug.global_allocator, "");
try formatType(inst, "", FormatOptions{}, &buf1, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 1);
std.testing.expect(mem.eql(u8, buf1.toSlice(), "S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }"));
var buf2 = try std.Buffer.init(std.debug.global_allocator, "");
try formatType(inst, "", FormatOptions{}, &buf2, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 2);
std.testing.expect(mem.eql(u8, buf2.toSlice(), "S{ .a = S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ ... } }, .e = E.Two, .vec = (10.200,2.220) }"));
var buf3 = try std.Buffer.init(std.debug.global_allocator, "");
try formatType(inst, "", FormatOptions{}, &buf3, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 3);
std.testing.expect(mem.eql(u8, buf3.toSlice(), "S{ .a = S{ .a = S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ ... } }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ .ptr = TU{ ... } } }, .e = E.Two, .vec = (10.200,2.220) }"));
}
test "positional" {
try testFmt("2 1 0", "{2} {1} {0}", @as(usize, 0), @as(usize, 1), @as(usize, 2));
try testFmt("2 1 0", "{2} {1} {}", @as(usize, 0), @as(usize, 1), @as(usize, 2));
try testFmt("0 0", "{0} {0}", @as(usize, 0));
try testFmt("0 1", "{} {1}", @as(usize, 0), @as(usize, 1));
try testFmt("1 0 0 1", "{1} {} {0} {}", @as(usize, 0), @as(usize, 1));
}
test "positional with specifier" {
try testFmt("10.0", "{0d:.1}", @as(f64, 9.999));
}
test "positional/alignment/width/precision" {
try testFmt("10.0", "{0d: >3.1}", @as(f64, 9.999));
}