Zig: completed Triangle

zig/triangle/.exercism/config.json

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+{
+  "authors": [
+    "massivelivefun"
+  ],
+  "files": {
+    "solution": [
+      "triangle.zig"
+    ],
+    "test": [
+      "test_triangle.zig"
+    ],
+    "example": [
+      ".meta/example.zig"
+    ]
+  },
+  "blurb": "Determine if a triangle is equilateral, isosceles, or scalene.",
+  "source": "The Ruby Koans triangle project, parts 1 & 2",
+  "source_url": "https://web.archive.org/web/20220831105330/http://rubykoans.com"
+}

zig/triangle/.exercism/metadata.json

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+{"track":"zig","exercise":"triangle","id":"60a9b567b2b646e7a31fc3b2ac5ee623","url":"https://exercism.org/tracks/zig/exercises/triangle","handle":"Chomp1295","is_requester":true,"auto_approve":false}

zig/triangle/HELP.md

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+# Help
+
+## Running the tests
+
+Write your code in `<exercise_name>.zig`.
+
+To run the tests for an exercise, run:
+
+```bash
+zig test test_exercise_name.zig
+```
+
+in the exercise's root directory (replacing `exercise_name` with the name of the exercise).
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit triangle.zig` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Zig track's documentation](https://exercism.org/docs/tracks/zig)
+- The [Zig track's programming category on the forum](https://forum.exercism.org/c/programming/zig)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+- [The Zig Programming Language Documentation][documentation] is a great overview of all of the language features that Zig provides to those who use it.
+- [Zig Guide][zig-guide] is an excellent primer that explains the language features that Zig has to offer.
+- [Ziglings][ziglings] is highly recommended.
+  Learn Zig by fixing tiny broken programs.
+- [The Zig Programming Language Discord][discord-zig] is the main [Discord][discord].
+  It provides a great way to get in touch with the Zig community at large, and get some quick, direct help for any Zig related problem.
+- [#zig][irc] on irc.freenode.net is the main Zig IRC channel.
+- [/r/Zig][reddit] is the main Zig subreddit.
+- [Stack Overflow][stack-overflow] can be used to discover code snippets and solutions to problems that may have already asked and maybe solved by others.
+
+[discord]: https://discordapp.com
+[discord-zig]: https://discord.com/invite/gxsFFjE
+[documentation]: https://ziglang.org/documentation/master
+[irc]: https://webchat.freenode.net/?channels=%23zig
+[reddit]: https://www.reddit.com/r/Zig
+[stack-overflow]: https://stackoverflow.com/questions/tagged/zig
+[zig-guide]: https://zig.guide/
+[ziglings]: https://codeberg.org/ziglings/exercises

zig/triangle/README.md

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+# Triangle
+
+Welcome to Triangle on Exercism's Zig Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Determine if a triangle is equilateral, isosceles, or scalene.
+
+An _equilateral_ triangle has all three sides the same length.
+
+An _isosceles_ triangle has at least two sides the same length.
+(It is sometimes specified as having exactly two sides the same length, but for the purposes of this exercise we'll say at least two.)
+
+A _scalene_ triangle has all sides of different lengths.
+
+## Note
+
+For a shape to be a triangle at all, all sides have to be of length > 0, and the sum of the lengths of any two sides must be greater than or equal to the length of the third side.
+
+In equations:
+
+Let `a`, `b`, and `c` be sides of the triangle.
+Then all three of the following expressions must be true:
+
+```text
+a + b ≥ c
+b + c ≥ a
+a + c ≥ b
+```
+
+See [Triangle Inequality][triangle-inequality]
+
+[triangle-inequality]: https://en.wikipedia.org/wiki/Triangle_inequality
+
+## Source
+
+### Created by
+
+- @massivelivefun
+
+### Based on
+
+The Ruby Koans triangle project, parts 1 & 2 - https://web.archive.org/web/20220831105330/http://rubykoans.com

zig/triangle/test_triangle.zig

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+const std = @import("std");
+const testing = std.testing;
+
+const triangle = @import("triangle.zig");
+
+test "equilateral all sides are equal" {
+    const actual = try triangle.Triangle.init(2, 2, 2);
+    try testing.expect(actual.isEquilateral());
+}
+
+test "equilateral any side is unequal" {
+    const actual = try triangle.Triangle.init(2, 3, 2);
+    try testing.expect(!actual.isEquilateral());
+}
+
+test "equilateral no sides are equal" {
+    const actual = try triangle.Triangle.init(5, 4, 6);
+    try testing.expect(!actual.isEquilateral());
+}
+
+test "equilateral all zero sides is not a triangle" {
+    const actual = triangle.Triangle.init(0, 0, 0);
+    try testing.expectError(triangle.TriangleError.Invalid, actual);
+}
+
+test "equilateral sides may be floats" {
+    const actual = try triangle.Triangle.init(0.5, 0.5, 0.5);
+    try testing.expect(actual.isEquilateral());
+}
+
+test "isosceles last two sides are equal" {
+    const actual = try triangle.Triangle.init(3, 4, 4);
+    try testing.expect(actual.isIsosceles());
+}
+
+test "isosceles first two sides are equal" {
+    const actual = try triangle.Triangle.init(4, 4, 3);
+    try testing.expect(actual.isIsosceles());
+}
+
+test "isosceles first and last sides are equal" {
+    const actual = try triangle.Triangle.init(4, 3, 4);
+    try testing.expect(actual.isIsosceles());
+}
+
+test "equilateral triangles are also isosceles" {
+    const actual = try triangle.Triangle.init(4, 3, 4);
+    try testing.expect(actual.isIsosceles());
+}
+
+test "isosceles no sides are equal" {
+    const actual = try triangle.Triangle.init(2, 3, 4);
+    try testing.expect(!actual.isIsosceles());
+}
+
+test "isosceles first triangle inequality violation" {
+    const actual = triangle.Triangle.init(1, 1, 3);
+    try testing.expectError(triangle.TriangleError.Invalid, actual);
+}
+
+test "isosceles second triangle inequality violation" {
+    const actual = triangle.Triangle.init(1, 3, 1);
+    try testing.expectError(triangle.TriangleError.Invalid, actual);
+}
+
+test "isosceles third triangle inequality violation" {
+    const actual = triangle.Triangle.init(3, 1, 1);
+    try testing.expectError(triangle.TriangleError.Invalid, actual);
+}
+
+test "isosceles sides may be floats" {
+    const actual = try triangle.Triangle.init(0.5, 0.4, 0.5);
+    try testing.expect(actual.isIsosceles());
+}
+
+test "scalene no sides are equal" {
+    const actual = try triangle.Triangle.init(5, 4, 6);
+    try testing.expect(actual.isScalene());
+}
+
+test "scalene all sides are equal" {
+    const actual = try triangle.Triangle.init(4, 4, 4);
+    try testing.expect(!actual.isScalene());
+}
+
+test "scalene first and second sides are equal" {
+    const actual = try triangle.Triangle.init(4, 4, 3);
+    try testing.expect(!actual.isScalene());
+}
+
+test "scalene first and third sides are equal" {
+    const actual = try triangle.Triangle.init(3, 4, 3);
+    try testing.expect(!actual.isScalene());
+}
+
+test "scalene second and third sides are equal" {
+    const actual = try triangle.Triangle.init(4, 3, 3);
+    try testing.expect(!actual.isScalene());
+}
+
+test "scalene may not violate triangle inequality" {
+    const actual = triangle.Triangle.init(7, 3, 2);
+    try testing.expectError(triangle.TriangleError.Invalid, actual);
+}
+
+test "scalene sides may be floats" {
+    const actual = try triangle.Triangle.init(0.5, 0.4, 0.6);
+    try testing.expect(actual.isScalene());
+}

zig/triangle/triangle.zig

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+pub const TriangleError = error{Invalid};
+
+pub const Triangle = struct {
+    a: f64,
+    b: f64,
+    c: f64,
+
+    fn isValid(a: f64, b: f64, c: f64) bool {
+        return (a > 0 and b > 0 and c > 0) and (a + b >= c and b + c >= a and a + c >= b);
+    }
+
+    pub fn init(a: f64, b: f64, c: f64) TriangleError!Triangle {
+        if (!isValid(a, b, c)) {
+            return error.Invalid;
+        }
+
+        return Triangle{ .a = a, .b = b, .c = c };
+    }
+
+    pub fn isEquilateral(self: Triangle) bool {
+        return self.a == self.b and self.b == self.c;
+    }
+
+    pub fn isIsosceles(self: Triangle) bool {
+        return self.a == self.b or self.a == self.c or self.b == self.c;
+    }
+
+    pub fn isScalene(self: Triangle) bool {
+        return self.a != self.b and self.a != self.c and self.b != self.c;
+    }
+};