summaryrefslogtreecommitdiffstats
path: root/googletest/docs/pump_manual.md
diff options
context:
space:
mode:
authorGennadiy Civil <misterg@google.com>2019-07-18 19:27:51 (GMT)
committerGennadiy Civil <misterg@google.com>2019-07-18 19:27:51 (GMT)
commitb77e5c76252bac322bb82c5b444f050bd0d92451 (patch)
tree13e73f0759e2bbd3014c6940433c97455387e563 /googletest/docs/pump_manual.md
parenta743249a5534eb57d3f5b4b0bb6d51b8dd2d5c68 (diff)
downloadgoogletest-b77e5c76252bac322bb82c5b444f050bd0d92451.zip
googletest-b77e5c76252bac322bb82c5b444f050bd0d92451.tar.gz
googletest-b77e5c76252bac322bb82c5b444f050bd0d92451.tar.bz2
Manual docs tweaks still in preparation for including docs with code pushes
Diffstat (limited to 'googletest/docs/pump_manual.md')
-rw-r--r--googletest/docs/pump_manual.md169
1 files changed, 91 insertions, 78 deletions
diff --git a/googletest/docs/pump_manual.md b/googletest/docs/pump_manual.md
index 3ec428e..10b3c5f 100644
--- a/googletest/docs/pump_manual.md
+++ b/googletest/docs/pump_manual.md
@@ -1,52 +1,51 @@
-
-
<b>P</b>ump is <b>U</b>seful for <b>M</b>eta <b>P</b>rogramming.
-# The Problem #
+# The Problem
-Template and macro libraries often need to define many classes,
-functions, or macros that vary only (or almost only) in the number of
-arguments they take. It's a lot of repetitive, mechanical, and
-error-prone work.
+Template and macro libraries often need to define many classes, functions, or
+macros that vary only (or almost only) in the number of arguments they take.
+It's a lot of repetitive, mechanical, and error-prone work.
-Variadic templates and variadic macros can alleviate the problem.
-However, while both are being considered by the C++ committee, neither
-is in the standard yet or widely supported by compilers. Thus they
-are often not a good choice, especially when your code needs to be
-portable. And their capabilities are still limited.
+Variadic templates and variadic macros can alleviate the problem. However, while
+both are being considered by the C++ committee, neither is in the standard yet
+or widely supported by compilers. Thus they are often not a good choice,
+especially when your code needs to be portable. And their capabilities are still
+limited.
-As a result, authors of such libraries often have to write scripts to
-generate their implementation. However, our experience is that it's
-tedious to write such scripts, which tend to reflect the structure of
-the generated code poorly and are often hard to read and edit. For
-example, a small change needed in the generated code may require some
-non-intuitive, non-trivial changes in the script. This is especially
-painful when experimenting with the code.
+As a result, authors of such libraries often have to write scripts to generate
+their implementation. However, our experience is that it's tedious to write such
+scripts, which tend to reflect the structure of the generated code poorly and
+are often hard to read and edit. For example, a small change needed in the
+generated code may require some non-intuitive, non-trivial changes in the
+script. This is especially painful when experimenting with the code.
-# Our Solution #
+# Our Solution
Pump (for Pump is Useful for Meta Programming, Pretty Useful for Meta
-Programming, or Practical Utility for Meta Programming, whichever you
-prefer) is a simple meta-programming tool for C++. The idea is that a
-programmer writes a `foo.pump` file which contains C++ code plus meta
-code that manipulates the C++ code. The meta code can handle
-iterations over a range, nested iterations, local meta variable
-definitions, simple arithmetic, and conditional expressions. You can
-view it as a small Domain-Specific Language. The meta language is
-designed to be non-intrusive (s.t. it won't confuse Emacs' C++ mode,
-for example) and concise, making Pump code intuitive and easy to
-maintain.
-
-## Highlights ##
-
- * The implementation is in a single Python script and thus ultra portable: no build or installation is needed and it works cross platforms.
- * Pump tries to be smart with respect to [Google's style guide](https://github.com/google/styleguide): it breaks long lines (easy to have when they are generated) at acceptable places to fit within 80 columns and indent the continuation lines correctly.
- * The format is human-readable and more concise than XML.
- * The format works relatively well with Emacs' C++ mode.
-
-## Examples ##
-
-The following Pump code (where meta keywords start with `$`, `[[` and `]]` are meta brackets, and `$$` starts a meta comment that ends with the line):
+Programming, or Practical Utility for Meta Programming, whichever you prefer) is
+a simple meta-programming tool for C++. The idea is that a programmer writes a
+`foo.pump` file which contains C++ code plus meta code that manipulates the C++
+code. The meta code can handle iterations over a range, nested iterations, local
+meta variable definitions, simple arithmetic, and conditional expressions. You
+can view it as a small Domain-Specific Language. The meta language is designed
+to be non-intrusive (s.t. it won't confuse Emacs' C++ mode, for example) and
+concise, making Pump code intuitive and easy to maintain.
+
+## Highlights
+
+* The implementation is in a single Python script and thus ultra portable: no
+ build or installation is needed and it works cross platforms.
+* Pump tries to be smart with respect to
+ [Google's style guide](https://github.com/google/styleguide): it breaks long
+ lines (easy to have when they are generated) at acceptable places to fit
+ within 80 columns and indent the continuation lines correctly.
+* The format is human-readable and more concise than XML.
+* The format works relatively well with Emacs' C++ mode.
+
+## Examples
+
+The following Pump code (where meta keywords start with `$`, `[[` and `]]` are
+meta brackets, and `$$` starts a meta comment that ends with the line):
```
$var n = 3 $$ Defines a meta variable n.
@@ -71,7 +70,7 @@ $if i == 0 [[
will be translated by the Pump compiler to:
-``` cpp
+```cpp
// Foo0 does blah for 0-ary predicates.
template <size_t N>
class Foo0 {
@@ -105,9 +104,10 @@ Func($for i + [[a$i]]);
$$ The text between i and [[ is the separator between iterations.
```
-will generate one of the following lines (without the comments), depending on the value of `n`:
+will generate one of the following lines (without the comments), depending on
+the value of `n`:
-``` cpp
+```cpp
Func(); // If n is 0.
Func(a1); // If n is 1.
Func(a1 + a2); // If n is 2.
@@ -115,32 +115,38 @@ Func(a1 + a2 + a3); // If n is 3.
// And so on...
```
-## Constructs ##
+## Constructs
We support the following meta programming constructs:
-| `$var id = exp` | Defines a named constant value. `$id` is valid util the end of the current meta lexical block. |
-|:----------------|:-----------------------------------------------------------------------------------------------|
-| `$range id exp..exp` | Sets the range of an iteration variable, which can be reused in multiple loops later. |
-| `$for id sep [[ code ]]` | Iteration. The range of `id` must have been defined earlier. `$id` is valid in `code`. |
-| `$($)` | Generates a single `$` character. |
-| `$id` | Value of the named constant or iteration variable. |
-| `$(exp)` | Value of the expression. |
-| `$if exp [[ code ]] else_branch` | Conditional. |
-| `[[ code ]]` | Meta lexical block. |
-| `cpp_code` | Raw C++ code. |
-| `$$ comment` | Meta comment. |
-
-**Note:** To give the user some freedom in formatting the Pump source
-code, Pump ignores a new-line character if it's right after `$for foo`
-or next to `[[` or `]]`. Without this rule you'll often be forced to write
-very long lines to get the desired output. Therefore sometimes you may
-need to insert an extra new-line in such places for a new-line to show
-up in your output.
-
-## Grammar ##
-
-``` ebnf
+| `$var id = exp` | Defines a named constant value. `$id` is |
+: : valid util the end of the current meta :
+: : lexical block. :
+| :------------------------------- | :--------------------------------------- |
+| `$range id exp..exp` | Sets the range of an iteration variable, |
+: : which can be reused in multiple loops :
+: : later. :
+| `$for id sep [[ code ]]` | Iteration. The range of `id` must have |
+: : been defined earlier. `$id` is valid in :
+: : `code`. :
+| `$($)` | Generates a single `$` character. |
+| `$id` | Value of the named constant or iteration |
+: : variable. :
+| `$(exp)` | Value of the expression. |
+| `$if exp [[ code ]] else_branch` | Conditional. |
+| `[[ code ]]` | Meta lexical block. |
+| `cpp_code` | Raw C++ code. |
+| `$$ comment` | Meta comment. |
+
+**Note:** To give the user some freedom in formatting the Pump source code, Pump
+ignores a new-line character if it's right after `$for foo` or next to `[[` or
+`]]`. Without this rule you'll often be forced to write very long lines to get
+the desired output. Therefore sometimes you may need to insert an extra new-line
+in such places for a new-line to show up in your output.
+
+## Grammar
+
+```ebnf
code ::= atomic_code*
atomic_code ::= $var id = exp
| $var id = [[ code ]]
@@ -159,19 +165,26 @@ else_branch ::= $else [[ code ]]
exp ::= simple_expression_in_Python_syntax
```
-## Code ##
+## Code
-You can find the source code of Pump in [scripts/pump.py](../scripts/pump.py). It is still
-very unpolished and lacks automated tests, although it has been
-successfully used many times. If you find a chance to use it in your
-project, please let us know what you think! We also welcome help on
-improving Pump.
+You can find the source code of Pump in [scripts/pump.py](../scripts/pump.py).
+It is still very unpolished and lacks automated tests, although it has been
+successfully used many times. If you find a chance to use it in your project,
+please let us know what you think! We also welcome help on improving Pump.
-## Real Examples ##
+## Real Examples
-You can find real-world applications of Pump in [Google Test](https://github.com/google/googletest/tree/master/googletest) and [Google Mock](https://github.com/google/googletest/tree/master/googlemock). The source file `foo.h.pump` generates `foo.h`.
+You can find real-world applications of Pump in
+[Google Test](https://github.com/google/googletest/tree/master/googletest) and
+[Google Mock](https://github.com/google/googletest/tree/master/googlemock). The
+source file `foo.h.pump` generates `foo.h`.
-## Tips ##
+## Tips
- * If a meta variable is followed by a letter or digit, you can separate them using `[[]]`, which inserts an empty string. For example `Foo$j[[]]Helper` generate `Foo1Helper` when `j` is 1.
- * To avoid extra-long Pump source lines, you can break a line anywhere you want by inserting `[[]]` followed by a new line. Since any new-line character next to `[[` or `]]` is ignored, the generated code won't contain this new line.
+* If a meta variable is followed by a letter or digit, you can separate them
+ using `[[]]`, which inserts an empty string. For example `Foo$j[[]]Helper`
+ generate `Foo1Helper` when `j` is 1.
+* To avoid extra-long Pump source lines, you can break a line anywhere you
+ want by inserting `[[]]` followed by a new line. Since any new-line
+ character next to `[[` or `]]` is ignored, the generated code won't contain
+ this new line.