Don't wrap RUNNABLE_EXAMPLE_COMPILE code in void main (#3561)

* [js] Don't wrap _COMPILE examples in `void main`

Remove unused var `stripedText`.

* Use 'Compile' button for _EXAMPLE_COMPILE

Also add tooltip for Run explaining code is wrapped in main if missing.

* Set button width in en, not px

* Update dspec_tester to not wrap main with _COMPILE

* Mention std.stdio.write auto imported in Run tooltip

* Use -main switch instead of dummy main

* [dspec_tester] Only auto-import std.stdio for _RUN

* Avoid using local extern vars

Author: ntrel

css/style.css

@@ -1622,7 +1622,7 @@ input.runButton, input.resetButton, input.argsButton, input.inputButton, input.e
     padding:3px 6px;
     text-decoration:none;
     text-shadow:1px 1px 0px #ffffff;
-    width: 50px;
+    width: 10en;
     margin: 2px;
     position: relative;
     z-index: 2;

dlang.org.ddoc

@@ -398,12 +398,16 @@ _=
 RELATIVE_LINK2=$(ALOCAL $1, $+)
 _=
 
+_=These take a ddoc example enclosed in `---`
 RUNNABLE_EXAMPLE=<div class="runnable-examples">
 $1
 </div>
+RUNNABLE_EXAMPLE_COMPILE=<div class="runnable-examples" data-compile=''>
+$1
+</div>
+_=These go inside a RUNNABLE_EXAMPLE macro invocation before the first `---`
 RUNNABLE_EXAMPLE_STDIN=<code class="runnable-examples-stdin">$0</code>
 RUNNABLE_EXAMPLE_ARGS=<code class="runnable-examples-args">$0</code>
-RUNNABLE_EXAMPLE_COMPILE=$(RUNNABLE_EXAMPLE $0)
 
 SAMPLESRC=$(SPANC sample_src, $(AHTTPS github.com/dlang/dmd/blob/master/samples/$0, /dmd/samples/d/$0))
 SCINI=$(TC pre, scini notranslate, $0)

js/run.js

@@ -38,8 +38,8 @@ void main(string[] args) {
 ------
 
 TL;DR
-All examples are replaced with custom form by default. You need to do additional work only if you wan't
-your example to have deafault standard input or default standard arguments.
+All examples are replaced with custom form by default. You need to do additional work only if you want
+your example to have default standard input or default standard arguments.
 */
 
 var nl2br = function()
@@ -102,7 +102,7 @@ var backends = {
         var req = {
             source: data.code,
             // always execute unittests and main for backwards compatibility with examples
-            args: "-unittest",
+            args: "-unittest -main",
             runtimeArgs: "--DRT-testmode=run-main",
             compiler: dmdCompilerBranch
         }
@@ -179,11 +179,11 @@ function parseOutput(res, o, oTitle)
 }
 
 // wraps a unittest into a runnable script
-function wrapIntoMain(code) {
+function wrapIntoMain(code, compile) {
     var currentPackage = $('body')[0].id;
 
     // dynamically wrap into main if needed
-    if (code.indexOf("void main") >= 0 || code.indexOf("int main") >= 0) {
+    if (compile || code.indexOf("void main") >= 0 || code.indexOf("int main") >= 0) {
         return code;
     }
     else {
@@ -207,7 +207,6 @@ $(document).ready(function()
     {
         var root = $(this);
         var el = root.children("pre");
-        var stripedText = el.text().replace(/\s/gm,'');
 
         var stdin = root.children(".runnable-examples-stdin").text();
         var args = root.children(".runnable-examples-args").text();
@@ -224,6 +223,11 @@ $(document).ready(function()
                 + '<textarea class="d_code_args">'+args+'</textarea></div>';
         }
 
+        var compile = el.parent()[0].hasAttribute('data-compile');
+        var runAttrs = `value="${compile ? 'Compile' : 'Run'}"`;
+        if (!compile)
+            runAttrs += ' title="Note: Wraps code in `main` automatically if `main` is missing'
+                + ' & imports std.stdio.write[f][ln]"';
         var currentExample = el;
         var orig = currentExample.html();
 
@@ -236,7 +240,7 @@ $(document).ready(function()
             + '<input type="button" class="editButton" value="Edit">'
             + (args.length > 0 ? '<input type="button" class="argsButton" value="Args">' : '')
             + (stdin.length > 0 ? '<input type="button" class="inputButton" value="Input">' : '')
-            + '<input type="button" class="runButton" value="Run">'
+            + `<input type="button" class="runButton" ${runAttrs}>`
             + '<input type="button" class="resetButton" value="Reset">'
             + '<input type="button" class="openInEditorButton" value="Open in IDE"></div>'
         );
@@ -247,11 +251,13 @@ $(document).ready(function()
         var outputDiv = parent.children("div.d_code_output");
         var hasStdin = parent.children(".inputButton").length > 0;
         var hasArgs  = parent.children(".argsButton").length > 0;
+        var compile = parent.parent()[0].hasAttribute('data-compile');
         setupTextarea(this, {
           parent: parent,
           outputDiv: outputDiv,
           stdin: hasStdin,
           args: hasArgs,
+          compile: compile,
           defaultOutput: "Succeed without output.",
           transformOutput: wrapIntoMain,
         });
@@ -421,7 +427,7 @@ function setupTextarea(el, opts)
         output.focus();
 
         var data = {
-          code: opts.transformOutput(editor.getValue())
+          code: opts.transformOutput(editor.getValue(), opts.compile)
         };
         if (opts.stdin) {
             data.stdin = stdin.val();

spec/arrays.dd

@@ -237,21 +237,16 @@ $(H2 $(LNAME2 slicing, Slicing))
         For example:
         )
 
-$(SPEC_RUNNABLE_EXAMPLE_COMPILE
+$(SPEC_RUNNABLE_EXAMPLE_RUN
 ---------
-void foo(int value)
-{
-  writeln("value=", value);
-}
-
 int[10] a;   // declare array of 10 ints
 int[] b;
 
 b = a[1..3]; // a[1..3] is a 2 element array consisting of
              // a[1] and a[2]
-foo(b[1]);   // equivalent to foo(0)
+assert(b[1] == 0);
 a[2] = 3;
-foo(b[1]);   // equivalent to foo(3)
+assert(b[1] == 3);
 ---------
 )
 
@@ -348,10 +343,13 @@ $(H3 $(LNAME2 overlapping-copying, Overlapping Copying))
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-int[3] s;
+void main()
+{
+    int[3] s;
 
-s[0..2] = s[1..3]; // error, overlapping copy
-s[1..3] = s[0..2]; // error, overlapping copy
+    s[0..2] = s[1..3]; // error, overlapping copy
+    s[1..3] = s[0..2]; // error, overlapping copy
+}
 ---------
 )
 
@@ -542,8 +540,14 @@ double[][] matrix;
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
+import std.stdio : writeln;
+
 double[6][3] matrix = 0; // Sets all elements to 0.
-writeln(matrix); // [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0]]
+
+void main()
+{
+    writeln(matrix); // [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0]]
+}
 ---------
 )
 
@@ -554,11 +558,16 @@ writeln(matrix); // [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0]]
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-double[6][3] matrix = 0;
-matrix[2][5] = 3.14; // Assignment to bottom right element.
-writeln(matrix); // [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 3.14]]
+import std.stdio : writeln;
+
+void main()
+{
+    double[6][3] matrix = 0;
+    matrix[2][5] = 3.14; // Assignment to bottom right element.
+    writeln(matrix); // [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 3.14]]
 
-static assert(!__traits(compiles, matrix[5][2])); // Array index out of bounds.
+    static assert(!__traits(compiles, matrix[5][2])); // Array index out of bounds.
+}
 ---------
 )
 
@@ -714,15 +723,18 @@ a[15] = 'z';   // does not affect c, because either a or c has reallocated.
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-int[] array;
-while (1)
+void fun()
 {
-    import core.stdc.stdio : getchar;
-    auto c = getchar;
-    if (!c)
-        break;
-    ++array.length;
-    array[array.length - 1] = c;
+    int[] array;
+    while (1)
+    {
+        import core.stdc.stdio : getchar;
+        auto c = getchar;
+        if (!c)
+            break;
+        ++array.length;
+        array[array.length - 1] = c;
+    }
 }
 ---------
 )
@@ -732,20 +744,23 @@ while (1)
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-int[] array;
-array.length = 100;        // guess
-int i;
-for (i = 0; ; i++)
+void fun()
 {
-    import core.stdc.stdio : getchar;
-    auto c = getchar;
-    if (!c)
-        break;
-    if (i == array.length)
-        array.length *= 2;
-    array[i] = c;
+    int[] array;
+    array.length = 100;        // guess
+    int i;
+    for (i = 0; ; i++)
+    {
+        import core.stdc.stdio : getchar;
+        auto c = getchar;
+        if (!c)
+            break;
+        if (i == array.length)
+            array.length *= 2;
+        array[i] = c;
+    }
+    array.length = i;
 }
-array.length = i;
 ---------
 )
 
@@ -853,18 +868,21 @@ $(H2 $(LNAME2 bounds, Array Bounds Checking))
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-import core.exception;
-try
+void main()
 {
-    auto array = [1, 2];
-    for (auto i = 0; ; i++)
+    import core.exception;
+    try
     {
-        array[i] = 5;
+        auto array = [1, 2];
+        for (auto i = 0; ; i++)
+        {
+            array[i] = 5;
+        }
+    }
+    catch (ArrayIndexError)
+    {
+        // terminate loop
     }
-}
-catch (ArrayIndexError)
-{
-    // terminate loop
 }
 ---------
 )
@@ -873,10 +891,13 @@ catch (ArrayIndexError)
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-auto array = [1, 2];
-for (auto i = 0; i < array.length; i++)
+void main()
 {
-    array[i] = 5;
+    auto array = [1, 2];
+    for (auto i = 0; i < array.length; i++)
+    {
+        array[i] = 5;
+    }
 }
 ---------
 )
@@ -1118,16 +1139,19 @@ cast(immutable(wchar) [])"abc" // this is an array of wchar characters
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-char c;
-wchar w;
-dchar d;
-
-c = 'b';     // c is assigned the character 'b'
-w = 'b';     // w is assigned the wchar character 'b'
-//w = 'bc';  // error - only one wchar character at a time
-w = "b"[0];  // w is assigned the wchar character 'b'
-w = "\r"[0]; // w is assigned the carriage return wchar character
-d = 'd';     // d is assigned the character 'd'
+void fun()
+{
+    char c;
+    wchar w;
+    dchar d;
+
+    c = 'b';     // c is assigned the character 'b'
+    w = 'b';     // w is assigned the wchar character 'b'
+    //w = 'bc';  // error - only one wchar character at a time
+    w = "b"[0];  // w is assigned the wchar character 'b'
+    w = "\r"[0]; // w is assigned the carriage return wchar character
+    d = 'd';     // d is assigned the character 'd'
+}
 ---------
 )
 

spec/attribute.dd

@@ -643,7 +643,7 @@ $(H2 $(LNAME2 static, $(D static) Attribute))
         other words, it means there is no $(D this) reference.
         )
 
-$(SPEC_RUNNABLE_EXAMPLE_COMPILE
+$(SPEC_RUNNABLE_EXAMPLE_RUN
 ---------------
 class Foo
 {
@@ -1072,8 +1072,6 @@ alias TP = __traits(getAttributes, foo);
 
 pragma(msg, TP); // prints tuple(3, 4, 7, (SSS))
 pragma(msg, TP[2]); // prints 7
-
-void main() {}
 ---
 )
 
@@ -1142,8 +1140,6 @@ pragma(msg, __traits(getAttributes, Outer!int.Inner));
 // prints tuple("foo", "bar")
 pragma(msg, __traits(getAttributes, Outer!int.Inner!int.z));
 // prints tuple("foo", "bar")
-
-void main() {}
 ---
 )
 

spec/const3.dd

@@ -571,8 +571,12 @@ $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 import core.atomic;
 
 shared int x;
-//x++; // error, use atomicOp instead
-x.atomicOp!"+="(1);
+
+void fun()
+{
+    //x++; // error, use atomicOp instead
+    x.atomicOp!"+="(1);
+}
 ---
 )
 $(P $(RED Warning:) An individual read or write operation on shared
@@ -607,10 +611,13 @@ $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 struct T;
 shared T* x;
 
-synchronized
+void fun()
 {
-    T* p = cast(T*)x;
-    // operate on `*p`
+    synchronized
+    {
+        T* p = cast(T*)x;
+        // operate on `*p`
+    }
 }
 ---
 )