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index.zig
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index.zig
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const std = @import("../index.zig");
const math = std.math;
const debug = std.debug;
const assert = debug.assert;
const mem = std.mem;
const builtin = @import("builtin");
const errol = @import("errol/index.zig");
const lossyCast = std.math.lossyCast;
const max_int_digits = 65;
/// 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.
pub fn format(context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, comptime fmt: []const u8, args: ...) Errors!void {
const State = enum {
Start,
OpenBrace,
CloseBrace,
FormatString,
Pointer,
};
comptime var start_index = 0;
comptime var state = State.Start;
comptime var next_arg = 0;
inline for (fmt) |c, i| {
switch (state) {
State.Start => switch (c) {
'{' => {
if (start_index < i) {
try output(context, fmt[start_index..i]);
}
start_index = i;
state = State.OpenBrace;
},
'}' => {
if (start_index < i) {
try output(context, fmt[start_index..i]);
}
state = State.CloseBrace;
},
else => {},
},
State.OpenBrace => switch (c) {
'{' => {
state = State.Start;
start_index = i;
},
'}' => {
try formatType(args[next_arg], fmt[0..0], context, Errors, output);
next_arg += 1;
state = State.Start;
start_index = i + 1;
},
'*' => state = State.Pointer,
else => {
state = State.FormatString;
},
},
State.CloseBrace => switch (c) {
'}' => {
state = State.Start;
start_index = i;
},
else => @compileError("Single '}' encountered in format string"),
},
State.FormatString => switch (c) {
'}' => {
const s = start_index + 1;
try formatType(args[next_arg], fmt[s..i], context, Errors, output);
next_arg += 1;
state = State.Start;
start_index = i + 1;
},
else => {},
},
State.Pointer => switch (c) {
'}' => {
try output(context, @typeName(@typeOf(args[next_arg]).Child));
try output(context, "@");
try formatInt(@ptrToInt(args[next_arg]), 16, false, 0, context, Errors, output);
next_arg += 1;
state = State.Start;
start_index = i + 1;
},
else => @compileError("Unexpected format character after '*'"),
},
}
}
comptime {
if (args.len != next_arg) {
@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,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
const T = @typeOf(value);
if (T == anyerror) {
try output(context, "error.");
return output(context, @errorName(value));
}
switch (@typeInfo(T)) {
builtin.TypeId.Int, builtin.TypeId.Float => {
return formatValue(value, fmt, context, Errors, output);
},
builtin.TypeId.Void => {
return output(context, "void");
},
builtin.TypeId.Bool => {
return output(context, if (value) "true" else "false");
},
builtin.TypeId.Optional => {
if (value) |payload| {
return formatType(payload, fmt, context, Errors, output);
} else {
return output(context, "null");
}
},
builtin.TypeId.ErrorUnion => {
if (value) |payload| {
return formatType(payload, fmt, context, Errors, output);
} else |err| {
return formatType(err, fmt, context, Errors, output);
}
},
builtin.TypeId.ErrorSet => {
try output(context, "error.");
return output(context, @errorName(value));
},
builtin.TypeId.Promise => {
return format(context, Errors, output, "promise@{x}", @ptrToInt(value));
},
builtin.TypeId.Enum, builtin.TypeId.Union, builtin.TypeId.Struct => {
const has_cust_fmt = comptime cf: {
const info = @typeInfo(T);
const defs = switch (info) {
builtin.TypeId.Struct => |s| s.defs,
builtin.TypeId.Union => |u| u.defs,
builtin.TypeId.Enum => |e| e.defs,
else => unreachable,
};
for (defs) |def| {
if (mem.eql(u8, def.name, "format")) {
break :cf true;
}
}
break :cf false;
};
if (has_cust_fmt) return value.format(fmt, context, Errors, output);
try output(context, @typeName(T));
switch (comptime @typeId(T)) {
builtin.TypeId.Enum => {
try output(context, ".");
try formatType(@tagName(value), "", context, Errors, output);
return;
},
builtin.TypeId.Struct => {
comptime var field_i = 0;
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)), "", context, Errors, output);
}
try output(context, " }");
},
builtin.TypeId.Union => {
const info = @typeInfo(T).Union;
if (info.tag_type) |UnionTagType| {
try output(context, "{ .");
try output(context, @tagName(UnionTagType(value)));
try output(context, " = ");
inline for (info.fields) |u_field| {
if (@enumToInt(UnionTagType(value)) == u_field.enum_field.?.value) {
try formatType(@field(value, u_field.name), "", context, Errors, output);
}
}
try output(context, " }");
} else {
try format(context, Errors, output, "@{x}", @ptrToInt(&value));
}
},
else => unreachable,
}
return;
},
builtin.TypeId.Pointer => |ptr_info| switch (ptr_info.size) {
builtin.TypeInfo.Pointer.Size.One => switch (@typeInfo(ptr_info.child)) {
builtin.TypeId.Array => |info| {
if (info.child == u8) {
return formatText(value, fmt, 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, context, Errors, output);
},
else => return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value)),
},
builtin.TypeInfo.Pointer.Size.Many => {
if (ptr_info.child == u8) {
if (fmt.len > 0 and fmt[0] == 's') {
const len = std.cstr.len(value);
return formatText(value[0..len], fmt, context, Errors, output);
}
}
return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value));
},
builtin.TypeInfo.Pointer.Size.Slice => {
if (fmt.len > 0 and ((fmt[0] == 'x') or (fmt[0] == 'X'))) {
return formatText(value, fmt, context, Errors, output);
}
const casted_value = ([]const u8)(value);
return output(context, casted_value);
},
},
builtin.TypeId.Array => |info| {
if (info.child == u8) {
return formatText(value, fmt, context, Errors, output);
}
return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(&value));
},
else => @compileError("Unable to format type '" ++ @typeName(T) ++ "'"),
}
}
fn formatValue(
value: var,
comptime fmt: []const u8,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (fmt.len > 0) {
if (fmt[0] == 'B') {
comptime var width: ?usize = null;
if (fmt.len > 1) {
if (fmt[1] == 'i') {
if (fmt.len > 2) width = comptime (parseUnsigned(usize, fmt[2..], 10) catch unreachable);
return formatBytes(value, width, 1024, context, Errors, output);
}
width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable);
}
return formatBytes(value, width, 1000, context, Errors, output);
}
}
comptime var T = @typeOf(value);
switch (@typeId(T)) {
builtin.TypeId.Float => return formatFloatValue(value, fmt, context, Errors, output),
builtin.TypeId.Int => return formatIntValue(value, fmt, context, Errors, output),
else => unreachable,
}
}
pub fn formatIntValue(
value: var,
comptime fmt: []const u8,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
comptime var radix = 10;
comptime var uppercase = false;
comptime var width = 0;
if (fmt.len > 0) {
switch (fmt[0]) {
'c' => {
if (@typeOf(value) == u8) {
if (fmt.len > 1) @compileError("Unknown format character: " ++ []u8{fmt[1]});
return formatAsciiChar(value, context, Errors, output);
}
},
'b' => {
radix = 2;
uppercase = false;
width = 0;
},
'd' => {
radix = 10;
uppercase = false;
width = 0;
},
'x' => {
radix = 16;
uppercase = false;
width = 0;
},
'X' => {
radix = 16;
uppercase = true;
width = 0;
},
else => @compileError("Unknown format character: " ++ []u8{fmt[0]}),
}
if (fmt.len > 1) width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable);
}
return formatInt(value, radix, uppercase, width, context, Errors, output);
}
fn formatFloatValue(
value: var,
comptime fmt: []const u8,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
comptime var width: ?usize = null;
comptime var float_fmt = 'e';
if (fmt.len > 0) {
float_fmt = fmt[0];
if (fmt.len > 1) width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable);
}
switch (float_fmt) {
'e' => try formatFloatScientific(value, width, context, Errors, output),
'.' => try formatFloatDecimal(value, width, context, Errors, output),
else => @compileError("Unknown format character: " ++ []u8{float_fmt}),
}
}
pub fn formatText(
bytes: []const u8,
comptime fmt: []const u8,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (fmt.len > 0) {
if (fmt[0] == 's') {
comptime var width = 0;
if (fmt.len > 1) width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable);
return formatBuf(bytes, width, context, Errors, output);
} else if ((fmt[0] == 'x') or (fmt[0] == 'X')) {
for (bytes) |c| {
try formatInt(c, 16, fmt[0] == 'X', 2, context, Errors, output);
}
return;
} else @compileError("Unknown format character: " ++ []u8{fmt[0]});
}
return output(context, bytes);
}
pub fn formatAsciiChar(
c: u8,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
return output(context, (*[1]u8)(&c)[0..]);
}
pub fn formatBuf(
buf: []const u8,
width: usize,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
try output(context, buf);
var leftover_padding = if (width > buf.len) (width - buf.len) else return;
const pad_byte: u8 = ' ';
while (leftover_padding > 0) : (leftover_padding -= 1) {
try output(context, (*[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,
maybe_precision: ?usize,
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 (maybe_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 (maybe_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(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, 0, context, Errors, output);
} else {
try output(context, "-");
if (exp > -10 and exp < 10) {
try output(context, "0");
}
try formatInt(-exp, 10, false, 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,
maybe_precision: ?usize,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
var x = 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 (maybe_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 (maybe_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.
debug.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,
width: ?usize,
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, width, 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,
width: usize,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
if (@typeOf(value).is_signed) {
return formatIntSigned(value, base, uppercase, width, context, Errors, output);
} else {
return formatIntUnsigned(value, base, uppercase, width, context, Errors, output);
}
}
fn formatIntSigned(
value: var,
base: u8,
uppercase: bool,
width: usize,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
const uint = @IntType(false, @typeOf(value).bit_count);
if (value < 0) {
const minus_sign: u8 = '-';
try output(context, (*[1]u8)(&minus_sign)[0..]);
const new_value = @intCast(uint, -(value + 1)) + 1;
const new_width = if (width == 0) 0 else (width - 1);
return formatIntUnsigned(new_value, base, uppercase, new_width, context, Errors, output);
} else if (width == 0) {
return formatIntUnsigned(@intCast(uint, value), base, uppercase, width, context, Errors, output);
} else {
const plus_sign: u8 = '+';
try output(context, (*[1]u8)(&plus_sign)[0..]);
const new_value = @intCast(uint, value);
const new_width = if (width == 0) 0 else (width - 1);
return formatIntUnsigned(new_value, base, uppercase, new_width, context, Errors, output);
}
}
fn formatIntUnsigned(
value: var,
base: u8,
uppercase: bool,
width: usize,
context: var,
comptime Errors: type,
output: fn (@typeOf(context), []const u8) Errors!void,
) Errors!void {
// max_int_digits accounts for the minus sign. when printing an unsigned
// number we don't need to do that.
var buf: [max_int_digits - 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 padding = if (width > digits_buf.len) (width - digits_buf.len) else 0;
if (padding > index) {
const zero_byte: u8 = '0';
var leftover_padding = padding - index;
while (true) {
try output(context, (*[1]u8)(&zero_byte)[0..]);
leftover_padding -= 1;
if (leftover_padding == 0) break;
}
mem.set(u8, buf[0..index], '0');
return output(context, buf);
} else {
const padded_buf = buf[index - padding ..];
mem.set(u8, padded_buf[0..padding], '0');
return output(context, padded_buf);
}
}
pub fn formatIntBuf(out_buf: []u8, value: var, base: u8, uppercase: bool, width: usize) usize {
var context = FormatIntBuf{
.out_buf = out_buf,
.index = 0,
};
formatInt(value, base, uppercase, width, &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 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 "fmt.parseInt" {
assert((parseInt(i32, "-10", 10) catch unreachable) == -10);
assert((parseInt(i32, "+10", 10) catch unreachable) == 10);
assert(if (parseInt(i32, " 10", 10)) |_| false else |err| err == error.InvalidCharacter);
assert(if (parseInt(i32, "10 ", 10)) |_| false else |err| err == error.InvalidCharacter);
assert(if (parseInt(u32, "-10", 10)) |_| false else |err| err == error.InvalidCharacter);
assert((parseInt(u8, "255", 10) catch unreachable) == 255);
assert(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);
x = try math.mul(T, x, radix);
x = try math.add(T, x, digit);
}
return x;
}
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) u8('A') else u8('a')) - 10),
else => unreachable,
};
}
const BufPrintContext = struct {
remaining: []u8,
};
fn bufPrintWrite(context: *BufPrintContext, bytes: []const u8) !void {
if (context.remaining.len < bytes.len) return error.BufferTooSmall;
mem.copy(u8, context.remaining, bytes);
context.remaining = context.remaining[bytes.len..];
}
pub fn bufPrint(buf: []u8, comptime fmt: []const u8, args: ...) ![]u8 {
var context = BufPrintContext{ .remaining = buf };
try format(&context, error{BufferTooSmall}, 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 "buf print int" {
var buffer: [max_int_digits]u8 = undefined;
const buf = buffer[0..];
assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 2, false, 0), "-101111000110000101001110"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 10, false, 0), "-12345678"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 16, false, 0), "-bc614e"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 16, true, 0), "-BC614E"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, u32(12345678), 10, true, 0), "12345678"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, u32(666), 10, false, 6), "000666"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, u32(0x1234), 16, false, 6), "001234"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, u32(0x1234), 16, false, 1), "1234"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(42), 10, false, 3), "+42"));
assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(-42), 10, false, 3), "-42"));
}
fn bufPrintIntToSlice(buf: []u8, value: var, base: u8, uppercase: bool, width: usize) []u8 {
return buf[0..formatIntBuf(buf, value, base, uppercase, width)];
}
test "parse u64 digit too big" {
_ = parseUnsigned(u64, "123a", 10) catch |err| {
if (err == error.InvalidCharacter) return;
unreachable;
};
unreachable;
}
test "parse unsigned comptime" {
comptime {
assert((try parseUnsigned(usize, "2", 10)) == 2);
}
}
test "fmt.format" {
{
const value: ?i32 = 1234;
try testFmt("optional: 1234\n", "optional: {}\n", value);
}
{
const value: ?i32 = null;
try testFmt("optional: null\n", "optional: {}\n", value);
}
{
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);
}
{
const value: u3 = 0b101;
try testFmt("u3: 5\n", "u3: {}\n", value);
}
{
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);
}
{
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,
);
}
{
const value: []const u8 = "abc";
try testFmt("slice: abc\n", "slice: {}\n", value);
}
{
const value = @intToPtr(*i32, 0xdeadbeef);
try testFmt("pointer: i32@deadbeef\n", "pointer: {}\n", value);
try testFmt("pointer: i32@deadbeef\n", "pointer: {*}\n", value);
}
try testFmt("buf: Test \n", "buf: {s5}\n", "Test");
try testFmt("buf: Test\n Other text", "buf: {s}\n Other text", "Test");
try testFmt("cstr: Test C\n", "cstr: {s}\n", c"Test C");
try testFmt("cstr: Test C \n", "cstr: {s10}\n", c"Test C");
try testFmt("file size: 63MiB\n", "file size: {Bi}\n", usize(63 * 1024 * 1024));
try testFmt("file size: 66.06MB\n", "file size: {B2}\n", usize(63 * 1024 * 1024));
{
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);
}
{
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);
}
{
var buf1: [32]u8 = undefined;
const value: f32 = 1.34;
const result = try bufPrint(buf1[0..], "f32: {e}\n", value);
assert(mem.eql(u8, result, "f32: 1.34000003e+00\n"));
}
{
var buf1: [32]u8 = undefined;
const value: f32 = 12.34;
const result = try bufPrint(buf1[0..], "f32: {e}\n", value);
assert(mem.eql(u8, result, "f32: 1.23400001e+01\n"));