Added error set examples (#277)

docs/examples/error-set-example-1.zig

@@ -0,0 +1,18 @@
+pub const FileOpenError = error{
+    access_denied,
+    out_of_memory,
+    file_not_found,
+};
+
+pub const AllocationError = error{
+    out_of_memory,
+};
+
+pub fn fail(reason: u32) !bool {
+    return switch (reason) {
+        1 => FileOpenError.access_denied,
+        2 => FileOpenError.out_of_memory,
+        3 => FileOpenError.file_not_found,
+        else => false,
+    };
+}

docs/examples/error-set-example-1a.js

@@ -0,0 +1,8 @@
+import { FileOpenError, fail } from './error-set-example-1.zig';
+
+try {
+  fail(2);
+} catch (err) {
+  console.log(err.message);
+  console.log(err === FileOpenError.out_of_memory);
+}

docs/examples/error-set-example-1b.js

@@ -0,0 +1,5 @@
+import { AllocationError, FileOpenError } from './error-set-example-1.zig';
+
+console.log(FileOpenError.out_of_memory === AllocationError.out_of_memory);
+console.log(FileOpenError.out_of_memory instanceof FileOpenError);
+console.log(AllocationError.out_of_memory instanceof AllocationError);

docs/examples/error-set-example-1c.js

@@ -0,0 +1,9 @@
+import { AllocationError, fail } from './error-set-example-1.zig';
+
+for (let i = 1; i <= 3; i++) {
+  try {
+    fail(i);
+  } catch (err) {
+    console.log(`${err.message}: ${err in AllocationError}`);
+  }   
+}

docs/examples/error-set-example-1d.js

@@ -0,0 +1,6 @@
+import { AllocationError, FileOpenError } from './error-set-example-1.zig';
+
+console.log(Number(FileOpenError.access_denied));
+console.log(Number(FileOpenError.out_of_memory));
+console.log(Number(FileOpenError.file_not_found));
+console.log(Number(AllocationError.out_of_memory));

docs/examples/error-set-example-1e.js

@@ -0,0 +1,6 @@
+import { AllocationError, FileOpenError } from './error-set-example-1.zig';
+
+console.log(String(FileOpenError.access_denied));
+console.log(String(FileOpenError.out_of_memory));
+console.log(String(FileOpenError.file_not_found));
+console.log(String(AllocationError.out_of_memory));

docs/examples/error-set-example-1f.js

@@ -0,0 +1,7 @@
+import { FileOpenError } from './error-set-example-1.zig';
+
+console.log(FileOpenError(47));
+console.log(FileOpenError('Error: Access denied'));
+console.log(FileOpenError('access_denied'));
+console.log(FileOpenError(42));
+

docs/examples/error-set-example-1g.js

@@ -0,0 +1,7 @@
+import { fail } from './error-set-example-1.zig';
+
+try {
+  fail(3);
+} catch (err) {
+  console.log(JSON.stringify(err));
+}

docs/examples/error-set-example-1h.js

@@ -0,0 +1,3 @@
+import { FileOpenError } from './error-set-example-1.zig';
+
+console.log(FileOpenError(JSON.parse('{"error":"File not found"}')));

docs/examples/error-set-example-2.js

@@ -0,0 +1,5 @@
+import { AnyError } from './error-set-example-2.zig';
+
+for (const [ name, err ] of AnyError) {
+  console.log(err.message);
+}

docs/examples/error-set-example-2.zig

@@ -0,0 +1,14 @@
+pub const FileOpenError = error{
+    access_denied,
+    out_of_memory,
+    file_not_found,
+};
+
+pub const HumanError = error{
+    got_into_crypto_currencies,
+    ran_out_of_beer,
+    did_not_know_how_to_use_a_condom,
+    hung_out_with_clifford_banes,
+};
+
+pub const AnyError = anyerror;

docs/examples/error-set-example-3.js

@@ -0,0 +1,7 @@
+import { fail } from './error-set-example-3.zig';
+
+try {
+  fail();
+} catch (err) {
+  console.log(err.message);
+}

docs/examples/error-set-example-3.zig

@@ -0,0 +1,5 @@
+const PrivateError = error{just_being_evil};
+
+pub fn fail() anyerror!bool {
+    return PrivateError.just_being_evil;
+}

docs/examples/error-set-example-4.js

@@ -0,0 +1,7 @@
+import { fail } from './error-set-example-4.zig';
+
+try {
+  fail();
+} catch (err) {
+  console.log(err.message);
+}

docs/examples/error-set-example-4.zig

@@ -0,0 +1,5 @@
+const PrivateError = error{just_being_evil};
+
+pub fn fail() !bool {
+    return PrivateError.just_being_evil;
+}