Add hacks to extract and compile tutorial code

Not included in the build by default, since it's fragile and kludgy. Do
something like this to run it:

    cd doc/tutorial
    RUSTC=../../build/stage2/bin/rustc bash test.sh

Closes #1143

13 files changed, 119 insertions, 14 deletions

diff --git a/doc/tutorial/args.md b/doc/tutorial/args.md
index 7c084687bb2..1797f5a23f5 100644
--- a/doc/tutorial/args.md
+++ b/doc/tutorial/args.md
@@ -22,6 +22,8 @@ other tasks, and that most data is immutable.
 
 Take the following program:
 
+    # fn get_really_big_record() -> int { 1 }
+    # fn myfunc(a: int) {}
     let x = get_really_big_record();
     myfunc(x);
 
@@ -32,6 +34,9 @@ existing value as the argument, without copying.
 
 There are more involved cases. The call could look like this:
 
+    # fn myfunc(a: int, b: block()) {}
+    # fn get_another_record() -> int { 1 }
+    # let x = 1;
     myfunc(x, {|| x = get_another_record(); });
 
 Now, if `myfunc` first calls its second argument and then accesses its
diff --git a/doc/tutorial/build.js b/doc/tutorial/build.js
index edefdfe3201..fb5f297c81e 100644
--- a/doc/tutorial/build.js
+++ b/doc/tutorial/build.js
@@ -4,7 +4,15 @@ require("./lib/codemirror-rust");
 
 md.Markdown.dialects.Maruku.block.code = function code(block, next) {
   if (block.match(/^    /)) {
-    var text = block.replace(/(^|\n)    /g, "$1"), accum = [], curstr = "", curstyle = null;
+    var text = String(block);
+    while (next.length && next[0].match(/^    /)) text += "\n" + String(next.shift());
+    var leaveAlone, accum = [], curstr = "", curstyle = null;
+    text = text.split("\n").map(function(line) {
+      line = line.slice(4);
+      if (line == "## notrust") leaveAlone = true;
+      return line;
+    }).filter(function(x) { return !/^##? /.test(x); }).join("\n");
+    if (leaveAlone) return [["pre", {}, text]];
     function add(str, style) {
       if (style != curstyle) {
         if (curstyle) accum.push(["span", {"class": "cm-" + curstyle}, curstr]);
diff --git a/doc/tutorial/control.md b/doc/tutorial/control.md
index 198d035accb..966aeb2df52 100644
--- a/doc/tutorial/control.md
+++ b/doc/tutorial/control.md
@@ -38,6 +38,7 @@ Rust's `alt` construct is a generalized, cleaned-up version of C's
 each labelled with a pattern, and it will execute the arm that matches
 the value.
 
+    # let my_number = 1;
     alt my_number {
       0       { std::io::println("zero"); }
       1 | 2   { std::io::println("one or two"); }
@@ -89,6 +90,7 @@ To a limited extent, it is possible to use destructuring patterns when
 declaring a variable with `let`. For example, you can say this to
 extract the fields from a tuple:
 
+    # fn get_tuple_of_two_ints() -> (int, int) { (1, 1) }
     let (a, b) = get_tuple_of_two_ints();
 
 This will introduce two new variables, `a` and `b`, bound to the
@@ -118,6 +120,8 @@ it finds one that can be divided by five.
 There's also `while`'s ugly cousin, `do`/`while`, which does not check
 its condition on the first iteration, using traditional syntax:
 
+    # fn eat_cake() {}
+    # fn any_cake_left() -> bool { false }
     do {
         eat_cake();
     } while any_cake_left();
diff --git a/doc/tutorial/data.md b/doc/tutorial/data.md
index 95ccb0ecec6..661fb2f0c6d 100644
--- a/doc/tutorial/data.md
+++ b/doc/tutorial/data.md
@@ -56,6 +56,7 @@ Records can be destructured on in `alt` patterns. The basic syntax is
 omitted as a shorthand for simply binding the variable with the same
 name as the field.
 
+    # let mypoint = {x: 0f, y: 0f};
     alt mypoint {
         {x: 0f, y: y_name} { /* Provide sub-patterns for fields */ }
         {x, y}             { /* Simply bind the fields */ }
@@ -71,6 +72,7 @@ the fields of a record, a record pattern may end with `, _` (as in
 Tags [FIXME terminology] are datatypes that have several different
 representations. For example, the type shown earlier:
 
+    # type point = {x: float, y: float};
     tag shape {
         circle(point, float);
         rectangle(point, point);
@@ -96,7 +98,7 @@ equivalent to an `enum` in C:
         east;
         south;
         west;
-    };
+    }
 
 This will define `north`, `east`, `south`, and `west` as constants,
 all of which have type `direction`.
@@ -116,6 +118,7 @@ That is a shorthand for this:
 Tag types like this can have their content extracted with the
 dereference (`*`) unary operator:
 
+    # tag gizmo_id = int;
     let my_gizmo_id = gizmo_id(10);
     let id_int: int = *my_gizmo_id;
 
@@ -125,6 +128,8 @@ For tag types with multiple variants, destructuring is the only way to
 get at their contents. All variant constructors can be used as
 patterns, as in this definition of `area`:
 
+    # type point = {x: float, y: float};
+    # tag shape { circle(point, float); rectangle(point, point); }
     fn area(sh: shape) -> float {
         alt sh {
             circle(_, size) { std::math::pi * size * size }
@@ -136,6 +141,8 @@ For variants without arguments, you have to write `variantname.` (with
 a dot at the end) to match them in a pattern. This to prevent
 ambiguity between matching a variant name and binding a new variable.
 
+    # type point = {x: float, y: float};
+    # tag direction { north; east; south; west; }
     fn point_from_direction(dir: direction) -> point {
         alt dir {
             north. { {x:  0f, y:  1f} }
@@ -295,6 +302,7 @@ strings. They are always immutable.
 
 Resources are data types that have a destructor associated with them.
 
+    # fn close_file_desc(x: int) {}
     resource file_desc(fd: int) {
         close_file_desc(fd);
     }
diff --git a/doc/tutorial/extract.js b/doc/tutorial/extract.js
new file mode 100644
index 00000000000..e8461967545
--- /dev/null
+++ b/doc/tutorial/extract.js
@@ -0,0 +1,42 @@
+var fs = require("fs"), md = require("./lib/markdown");
+
+// Runs markdown.js over the tutorial, to find the code blocks in it.
+// Uses the #-markers in those code blocks, along with some vague
+// heuristics, to turn them into compilable files. Outputs these files
+// to fragments/.
+//
+// '##ignore' means don't test this block
+// '##notrust' means the block isn't rust code
+//     (used by build.js to not highlight it)
+// '# code' means insert the given code to complete the fragment
+//     (build.js strips out such lines)
+
+var curFile, curFrag;
+md.Markdown.dialects.Maruku.block.code = function code(block, next) {
+  if (block.match(/^    /)) {
+    var ignore, text = String(block);
+    while (next.length && next[0].match(/^    /)) text += "\n" + String(next.shift());
+    text = text.split("\n").map(function(line) {
+      line = line.slice(4);
+      if (line == "## ignore" || line == "## notrust") { ignore = true; line = ""; }
+      if (/^# /.test(line)) line = line.slice(2);
+      return line;
+    }).join("\n");
+    if (ignore) return;
+    if (!/\bfn main\b/.test(text)) {
+      if (/(^|\n) *(native|use|mod|import|export)\b/.test(text))
+        text += "\nfn main() {}\n";
+      else text = "fn main() {\n" + text + "\n}\n";
+    }
+    if (!/\buse std\b/.test(text)) text = "use std;\n" + text;
+    fs.writeFileSync("fragments/" + curFile + "_" + (++curFrag) + ".rs", text);
+  }
+};
+
+fs.readFileSync("order", "utf8").split("\n").filter(id).forEach(handle);
+
+function id(x) { return x; }
+function handle(file) {
+  curFile = file; curFrag = 0;
+  md.parse(fs.readFileSync(file + ".md", "utf8"), "Maruku");
+}
diff --git a/doc/tutorial/ffi.md b/doc/tutorial/ffi.md
index cca3669f10d..7b90f64a6ba 100644
--- a/doc/tutorial/ffi.md
+++ b/doc/tutorial/ffi.md
@@ -67,6 +67,7 @@ most notably the Windows API, use other calling conventions, so Rust
 provides a way to to hint to the compiler which is expected by using
 the `"abi"` attribute:
 
+    #[cfg(target_os = "win32")]
     #[abi = "stdcall"]
     native mod kernel32 {
         fn SetEnvironmentVariableA(n: *u8, v: *u8) -> int;
@@ -81,7 +82,9 @@ or `"stdcall"`. Other conventions may be defined in the future.
 The native `SHA1` function is declared to take three arguments, and
 return a pointer.
 
+    # native mod crypto {
     fn SHA1(src: *u8, sz: uint, out: *u8) -> *u8;
+    # }
 
 When declaring the argument types to a foreign function, the Rust
 compiler has no way to check whether your declaration is correct, so
@@ -106,6 +109,9 @@ null pointers.
 
 The `sha1` function is the most obscure part of the program.
 
+    # import std::{str, vec};
+    # mod crypto { fn SHA1(src: *u8, sz: uint, out: *u8) -> *u8 { out } }
+    # fn as_hex(data: [u8]) -> str { "hi" }
     fn sha1(data: str) -> str unsafe {
         let bytes = str::bytes(data);
         let hash = crypto::SHA1(vec::unsafe::to_ptr(bytes),
@@ -141,10 +147,15 @@ Rust's safety mechanisms.
 
 Let's look at our `sha1` function again.
 
+    # import std::{str, vec};
+    # mod crypto { fn SHA1(src: *u8, sz: uint, out: *u8) -> *u8 { out } }
+    # fn as_hex(data: [u8]) -> str { "hi" }
+    # fn x(data: str) -> str unsafe {
     let bytes = str::bytes(data);
     let hash = crypto::SHA1(vec::unsafe::to_ptr(bytes),
                             vec::len(bytes), std::ptr::null());
     ret as_hex(vec::unsafe::from_buf(hash, 20u));
+    # }
 
 The `str::bytes` function is perfectly safe, it converts a string to
 an `[u8]`. This byte array is then fed to `vec::unsafe::to_ptr`, which
diff --git a/doc/tutorial/func.md b/doc/tutorial/func.md
index c174b904fb9..15811da04b3 100644
--- a/doc/tutorial/func.md
+++ b/doc/tutorial/func.md
@@ -19,6 +19,10 @@ This helps the compiler avoid spurious error messages. For example,
 the following code would be a type error if `dead_end` would be
 expected to return.
 
+    # fn can_go_left() -> bool { true }
+    # fn can_go_right() -> bool { true }
+    # tag dir { left; right; }
+    # fn dead_end() -> ! { fail; }
     let dir = if can_go_left() { left }
               else if can_go_right() { right }
               else { dead_end(); };
@@ -96,12 +100,14 @@ of integers backwards:
 
 To run such an iteration, you could do this:
 
+    # fn for_rev(v: [int], act: block(int)) {}
     for_rev([1, 2, 3], {|n| log n; });
 
 But Rust allows a more pleasant syntax for this situation, with the
 loop block moved out of the parenthesis and the final semicolon
 omitted:
 
+    # fn for_rev(v: [int], act: block(int)) {}
     for_rev([1, 2, 3]) {|n|
         log n;
     }
diff --git a/doc/tutorial/generic.md b/doc/tutorial/generic.md
index 43459665be5..02d37fd0e9b 100644
--- a/doc/tutorial/generic.md
+++ b/doc/tutorial/generic.md
@@ -55,16 +55,17 @@ dereferences become impossible.
 Rust's type inferrer works very well with generics, but there are
 programs that just can't be typed.
 
-    let n = none;
+    let n = std::option::none;
+    # n = std::option::some(1);
 
 If you never do anything else with `n`, the compiler will not be able
 to assign a type to it. (The same goes for `[]`, in fact.) If you
 really want to have such a statement, you'll have to write it like
 this:
 
-    let n2: option::t<int> = none;
+    let n2: std::option::t<int> = std::option::none;
     // or
-    let n = none::<int>;
+    let n = std::option::none::<int>;
 
 Note that, in a value expression, `<` already has a meaning as a
 comparison operator, so you'll have to write `::<T>` to explicitly
@@ -120,6 +121,7 @@ take sendable types.
 
 If you try this program:
 
+    # fn map(f: block(int) -> int, v: [int]) {}
     fn plus1(x: int) -> int { x + 1 }
     map(plus1, [1, 2, 3]);
 
@@ -131,6 +133,7 @@ way to pass integers, which is by value. To get around this issue, you
 have to explicitly mark the arguments to a function that you want to
 pass to a generic higher-order function as being passed by pointer:
 
+    # fn map<T, U>(f: block(T) -> U, v: [T]) {}
     fn plus1(&&x: int) -> int { x + 1 }
     map(plus1, [1, 2, 3]);
 
diff --git a/doc/tutorial/mod.md b/doc/tutorial/mod.md
index 24e498bcdb3..86151a9b9d5 100644
--- a/doc/tutorial/mod.md
+++ b/doc/tutorial/mod.md
@@ -35,6 +35,7 @@ It is also possible to include multiple files in a crate. For this
 purpose, you create a `.rc` crate file, which references any number of
 `.rs` code files. A crate file could look like this:
 
+    ## ignore
     #[link(name = "farm", vers = "2.5", author = "mjh")];
     mod cow;
     mod chicken;
@@ -52,6 +53,7 @@ in a moment.
 To have a nested directory structure for your source files, you can
 nest mods in your `.rc` file:
 
+    ## ignore
     mod poultry {
         mod chicken;
         mod turkey;
@@ -79,6 +81,7 @@ OS X.
 It is possible to provide more specific information when using an
 external crate.
 
+    ## ignore
     use myfarm (name = "farm", vers = "2.7");
 
 When a comma-separated list of name/value pairs is given after `use`,
@@ -90,6 +93,7 @@ local name `myfarm`.
 
 Our example crate declared this set of `link` attributes:
 
+    ## ignore
     #[link(name = "farm", vers = "2.5", author = "mjh")];
 
 The version does not match the one provided in the `use` directive, so
@@ -105,12 +109,14 @@ these two files:
     #[link(name = "mylib", vers = "1.0")];
     fn world() -> str { "world" }
 
+    ## ignore
     // main.rs
     use mylib;
     fn main() { log_err "hello " + mylib::world(); }
 
 Now compile and run like this (adjust to your platform if necessary):
 
+    ## notrust
     > rustc --lib mylib.rs
     > rustc main.rs -L .
     > ./main
@@ -147,8 +153,8 @@ restricted with `export` directives at the top of the module or file.
     mod enc {
         export encrypt, decrypt;
         const super_secret_number: int = 10;
-        fn encrypt(n: int) { n + super_secret_number }
-        fn decrypt(n: int) { n - super_secret_number }
+        fn encrypt(n: int) -> int { n + super_secret_number }
+        fn decrypt(n: int) -> int { n - super_secret_number }
     }
 
 This defines a rock-solid encryption algorithm. Code outside of the
diff --git a/doc/tutorial/setup.md b/doc/tutorial/setup.md
index 44d99891f76..1ec77b5630e 100644
--- a/doc/tutorial/setup.md
+++ b/doc/tutorial/setup.md
@@ -21,6 +21,7 @@ If you modify the program to make it invalid (for example, remove the
 `use std` line), and then compile it, you'll see an error message like
 this:
 
+    ## notrust
     hello.rs:2:4: 2:20 error: unresolved modulename: std
     hello.rs:2     std::io::println("hello world!");
                    ^~~~~~~~~~~~~~~~
diff --git a/doc/tutorial/syntax.md b/doc/tutorial/syntax.md
index 819df605d3a..d7be8df79dc 100644
--- a/doc/tutorial/syntax.md
+++ b/doc/tutorial/syntax.md
@@ -21,6 +21,7 @@ statements and expressions is C-like. Function calls are written
 precedence that they have in C, comments look the same, and constructs
 like `if` and `while` are available:
 
+    # fn call_a_function(_a: int) {}
     fn main() {
         if 1 < 2 {
             while false { call_a_function(10 * 4); }
@@ -39,10 +40,13 @@ of languages. A lot of thing that are statements in C are expressions
 in Rust. This allows for useless things like this (which passes
 nil—the void type—to a function):
 
+    # fn a_function(_a: ()) {}
     a_function(while false {});
 
 But also useful things like this:
 
+    # fn the_stars_align() -> bool { false }
+    # fn something_else() -> bool { true }
     let x = if the_stars_align() { 4 }
             else if something_else() { 3 }
             else { 0 };
@@ -125,6 +129,7 @@ annotation:
 
     // The type of this vector will be inferred based on its use.
     let x = [];
+    # x = [3];
     // Explicitly say this is a vector of integers.
     let y: [int] = [];
 
@@ -272,6 +277,7 @@ The comparison operators are the traditional `==`, `!=`, `<`, `>`,
 
 Rust has a ternary conditional operator `?:`, as in:
 
+    let badness = 12;
     let message = badness < 10 ? "error" : "FATAL ERROR";
 
 For type casting, Rust uses the binary `as` operator, which has a
@@ -311,19 +317,14 @@ followed by a comma-separated list of nested attributes, as in the
 `cfg` example above, or in this [crate](mod.html) metadata
 declaration:
 
+    ## ignore
     #[link(name = "std",
            vers = "0.1",
            url = "http://rust-lang.org/src/std")];
 
 An attribute without a semicolon following it applies to the
 definition that follows it. When terminated with a semicolon, it
-applies to the current context. The above example could also be
-written like this:
-
-    fn register_win_service() {
-        #[cfg(target_os = "win32")];
-        /* ... */
-    }
+applies to the module or crate.
 
 ## Syntax extensions
 
diff --git a/doc/tutorial/test.md b/doc/tutorial/test.md
index b7185c51085..b60250217e8 100644
--- a/doc/tutorial/test.md
+++ b/doc/tutorial/test.md
@@ -21,6 +21,7 @@ When you compile the program normally, the `test_twice` function will
 not be used. To actually run the tests, compile with the `--test`
 flag:
 
+    ## notrust
     > rustc --lib twice.rs
     > ./twice
     running 1 tests
@@ -30,6 +31,7 @@ flag:
 Or, if we change the file to fail, for example by replacing `x + x`
 with `x + 1`:
 
+    ## notrust
     running 1 tests
     test test_twice ... FAILED
     failures:
diff --git a/doc/tutorial/test.sh b/doc/tutorial/test.sh
new file mode 100644
index 00000000000..9cdb1aa9f8e
--- /dev/null
+++ b/doc/tutorial/test.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+rm -f fragments/*.rs
+mkdir -p fragments
+node extract.js
+for F in `ls fragments/*.rs`; do
+  $RUSTC $F > /dev/null
+  if [[ $? != 0 ]] ; then echo $F; fi
+done