| ... | @@ -134,6 +134,58 @@ pub fn main() void { | ... | @@ -134,6 +134,58 @@ pub fn main() void { |
| 134 | </p> | 134 | </p> |
| 135 | {#see_also|Values|@import|Errors|Root Source File#} | 135 | {#see_also|Values|@import|Errors|Root Source File#} |
| 136 | {#header_close#} | 136 | {#header_close#} |
| | 137 | {#header_open|Comments#} |
| | 138 | {#code_begin|test|comments#} |
| | 139 | const assert = @import("std").debug.assert; |
| | 140 | |
| | 141 | test "comments" { |
| | 142 | // Comments in Zig start with "//" and end at the next LF byte (end of line). |
| | 143 | // The below line is a comment, and won't be executed. |
| | 144 | |
| | 145 | //assert(false); |
| | 146 | |
| | 147 | const x = true; // another comment |
| | 148 | assert(x); |
| | 149 | } |
| | 150 | {#code_end#} |
| | 151 | <p> |
| | 152 | There are no multiline comments in Zig (e.g. like <code>/* */</code> |
| | 153 | comments in C). This helps allow Zig to have the property that each line |
| | 154 | of code can be tokenized out of context. |
| | 155 | </p> |
| | 156 | {#header_open|Doc comments#} |
| | 157 | <p> |
| | 158 | A doc comment is one that begins with exactly three slashes (i.e. |
| | 159 | <code class="zig">///</code> but not <code class="zig">////</code>); |
| | 160 | multiple doc comments in a row are merged together to form a multiline |
| | 161 | doc comment. The doc comment documents whatever immediately follows it. |
| | 162 | </p> |
| | 163 | {#code_begin|syntax|doc_comments#} |
| | 164 | /// A structure for storing a timestamp, with nanosecond precision (this is a |
| | 165 | /// multiline doc comment). |
| | 166 | const Timestamp = struct { |
| | 167 | /// The number of seconds since the epoch (this is also a doc comment). |
| | 168 | seconds: i64, // signed so we can represent pre-1970 (not a doc comment) |
| | 169 | /// The number of nanoseconds past the second (doc comment again). |
| | 170 | nanos: u32, |
| | 171 | |
| | 172 | /// Returns a `Timestamp` struct representing the Unix epoch; that is, the |
| | 173 | /// moment of 1970 Jan 1 00:00:00 UTC (this is a doc comment too). |
| | 174 | pub fn unixEpoch() Timestamp { |
| | 175 | return Timestamp{ |
| | 176 | .seconds = 0, |
| | 177 | .nanos = 0, |
| | 178 | }; |
| | 179 | } |
| | 180 | }; |
| | 181 | {#code_end#} |
| | 182 | <p> |
| | 183 | Doc comments are only allowed in certain places; eventually, it will |
| | 184 | become a compile error have a doc comment in an unexpected place, such as |
| | 185 | in the middle of an expression, or just before a non-doc comment. |
| | 186 | </p> |
| | 187 | {#header_close#} |
| | 188 | {#header_close#} |
| 137 | {#header_open|Values#} | 189 | {#header_open|Values#} |
| 138 | {#code_begin|exe|values#} | 190 | {#code_begin|exe|values#} |
| 139 | const std = @import("std"); | 191 | const std = @import("std"); |
Matthew D. Steele <mdsteele@alum.mit.edu> 2018-07-30 22:27:07-04:00
Andrew Kelley <andrew@ziglang.org> 2018-07-30 22:27:07-04:00