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+//
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+// Zig has support for IEEE-754 floating-point numbers in these
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+// specific sizes: f16, f32, f64, f128. Floating point literals
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+// may be writen in scientific notation:
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+//
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+// const a1: f32 = 1200.0; // 1,200
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+// const a2: f32 = 1.2e+3; // 1,200
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+// const b1: f32 = -500_000.0; // -500,000
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+// const b2: f32 = -5.0e+5; // -500,000
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+//
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+// Hex floats can't use the letter 'e' because that's a hex
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+// digit, so we use a 'p' instead:
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+//
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+// const hex: f16 = 0x2A.F7p+3; // Wow, that's arcane!
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+//
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+// Be sure to use a float type that is large enough to store your
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+// value (both in terms of significant digits and scale).
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+// Rounding may or may not be okay, but numbers which are too
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+// large or too small become inf or -inf (positive or negative
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+// infinity)!
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+//
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+// const pi: f16 = 3.1415926535; // rounds to 3.140625
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+// const av: f16 = 6.02214076e+23; // Avogadro's inf(inity)!
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+//
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+// A float literal has a decimal point. When performing math
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+// operations with numeric literals, ensure the types match. Zig
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+// does not perform unsafe type coercions behind your back:
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+//
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+// var foo: f16 = 13.5 * 5; // ERROR!
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+// var foo: f16 = 13.5 * 5.0; // No problem, both are floats
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+//
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+// Please fix the two float problems with this program and
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+// display the result as a whole number.
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+
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+const print = @import("std").debug.print;
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+
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+pub fn main() void {
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+ // The approximate weight of the Space Shuttle upon liftoff
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+ // (including boosters and fuel tank) was 2,200 tons.
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+ //
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+ // We'll convert this weight from tons to kilograms at a
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+ // conversion of 907.18kg to the ton.
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+ var shuttle_weight: f16 = 907.18 * 2200;
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+
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+ // By default, float values are formatted in scientific
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+ // notation. Try experimenting with '{d}' and '{d:.3}' to see
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+ // how decimal formatting works.
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+ print("Shuttle liftoff weight: {d:.0}kg\n", .{shuttle_weight});
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+}
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+
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+// Floating further:
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+//
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+// As an example, Zig's f16 is a IEEE 754 "half-precision" binary
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+// floating-point format ("binary16"), which is stored in memory
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+// like so:
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+//
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+// 0 1 0 0 0 0 1 0 0 1 0 0 1 0 0 0
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+// | |-------| |-----------------|
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+// | exponent significand
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+// |
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+// sign
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+//
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+// This example is the decimal number 3.140625, which happens to
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+// be the closest representation of Pi we can make with an f16
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+// due to the way IEEE-754 floating points store digits:
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+//
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+// * Sign bit 0 makes the number positive.
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+// * Exponent bits 10000 are a scale of 16.
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+// * Significand bits 1001001000 are the decimal value 584.
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+//
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+// IEEE-754 saves space by modifying these values: the value
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+// 01111 is always subtracted from the exponent bits (in our
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+// case, 10000 - 01111 = 1, so our exponent is 2^1) and our
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+// significand digits become the decimal value _after_ an
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+// implicit 1 (so 1.1001001000 or 1.5703125 in decimal)! This
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+// gives us:
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+//
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+// 2^1 * 1.5703125 = 3.140625
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+//
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+// Feel free to forget these implementation details immediately.
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+// The important thing to know is that floating point numbers are
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+// great at storing big and small values (f64 lets you work with
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+// numbers on the scale of the number of atoms in the universe),
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+// but digits may be rounded, leading to results which are less
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+// precise than integers.
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+//
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+// Fun fact: sometimes you'll see the significand labeled as a
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+// "mantissa" but Donald E. Knuth says not to do that.
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+//
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+// C compatibility fact: There is also a Zig floating point type
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+// specifically for working with C ABIs called c_longdouble.
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Dave Gauer