From 5d5892dbbf42deb4eb4c6e9b85befb0d7a59f1f3 Mon Sep 17 00:00:00 2001 From: Emiel Bruijntjes Date: Wed, 5 Mar 2014 15:36:09 +0100 Subject: updated documentation about functions, introducted += operator with a Php::Value on the right side, and an integral variable on the left --- documentation/functions.html | 124 ++++++++++-------------------------------- documentation/parameters.html | 58 ++++++++++++++++++++ include/value.h | 18 ++++++ 3 files changed, 106 insertions(+), 94 deletions(-) create mode 100644 documentation/parameters.html diff --git a/documentation/functions.html b/documentation/functions.html index 1d2d46b..1590520 100644 --- a/documentation/functions.html +++ b/documentation/functions.html @@ -126,109 +126,45 @@ extern "C" { }

- - - - -

-

- What do we see here? We've added four function declarations ("example1", - "example2", "example3" and "example4") to the source code of our extension. - The reason why we've only declared the functions, and not fully implemented - them is to keep the example code relatively small. We assume that the - four example functions are implemented in a different file. In a real world - example you could just as well remove the "extern" keyword and implement the - four functions in the same source file as the get_module() call. -

-

- The four functions all have a different signature: Some return a value, while - others do not return anything. And some take parameters, while others do not. - Despite the different signature of the functions, they can all be made - available in PHP by adding them to the extension object, by simply calling - the myExtension.add() method. This method takes two parameters: the name by - which the function should be accessible in PHP, and the actual native - function. -

-

- In the example above we've used different names for the native functions - ("example1" up to "example4") as for the PHP functions ("native1" to - "native4"). This is legal - you do not have to use the same names for your - native functions as for your PHP functions. The following PHP script can be - used to call the four native functions: + The above example shows how to work with parameters. The Php::Parameters class + is in reality nothing less than a std::vector filled with Php::Value objects - + and you can thus iterate over it. In this example we use the new C++11 way of + iterating, and the new-for-C++11 auto keyword to ask the compiler to find out + what type of variables are stored in the parameters vector (it are Php::Value + objects).

- 

-        <?php
-        native1();
-        native2("a","b");
-        $x = native3();
-        $y = native4(1,2);
-        ?>
-
+ And once again you can see how powerful this cute Php::Value class is. It can + for example be used on the right hand side of a += operator to be added to + an integer value, and the final integer result variable is automatically + converted back into a Php::Value object when the function returns - just as if + you are working with regular PHP $variables. But remember, this is C++ code and + therefore much, much faster!

- It is not possible to export every thinkable C/C++ function to the - PHP extension. Only functions that have one of the four supported signatures - can be exported: functions that return - void or a Php::Value object, and that either accept a Php::Parameters object - or no parameters at all, can be added to the extension object and can thus - be exported to PHP. + The sum_everything() function that we just made is now accessible from your + PHP script. Let's run a test.

-

Parameter types

- PHP has a mechanism to enforce function parameters types, and to accept - parameters either by reference or by value. In the examples above, we have - not yet used that mechanism yes: it is up to the function implementations - themselves to inspect the 'Parameters' object, and check if the - variables are of the right type. +


+<?php
+    echo(sum_everything(10,"100",20)."\n");
+?>
+

- However, the 'Extension::add()' method takes a third optional parameter that - you can use to specify the number of parameters that are supported, whether - the parameters are passed by reference or by value, and what the type of - the parameters is: + The output of the above script is, of course, 130. Do you want an even + funnier example? This outputs 130 too:

-


-#include <phpcpp.h>
-
-extern void example(Php::Parameters &params);
-
-extern "C" {
-    PHPCPP_EXPORT void *get_module() {
-        static Php::Extension myExtension("my_extension", "1.0");
-        myExtension.add("example", example, {
-            Php::ByVal("a", Php::Type::Numeric),
-            Php::ByVal("b", "ExampleClass"),
-            Php::ByRef("c", "OtherClass")
-        });
-        return myExtension.module();
+

+<?php
+    class MyClass {
+        public function __toString() {
+            return 20;
+        }
     }
-}
-

-

-

-    Above you see that we passed in additional information when we registered the
-    "example" function. We tell our extension that our function accepts three parameters:
-    the first parameter must be a regular number, while the other ones are object 
-    instances of type "ExampleClass" and "OtherClass". In the end, your native C++ 
-    "example" function will still be called with a Php::Parameters instance, but 
-    the moment it gets called, you can be sure that the Php::Parameters object 
-    will be filled with three members, and that two of them are objects of the 
-    appropriate type, and that the third one is also passed by reference.
-

-
Working with variables

-

-    Variables in PHP are non-typed. A variable can thus hold any possible type:
-    an integer, string, a floating point number, and even an object or an array.
-    C++ on the other hand is a typed language. In C++ an integer variable always 
-    has a numeric value, and a string variable always hold a string value.
-

-

-    When you mix native code and PHP code, you will need to convert the non-typed 
-    PHP variables into native variables, and the other way round: convert native 
-    variables back into non-typed PHP variables. The PHP-CPP library offers the 
-    "Value" class that makes this a very simple task.
+    echo(sum_everything(10,"100",new MyClass())."\n");
+?>
+

-

- \ No newline at end of file diff --git a/documentation/parameters.html b/documentation/parameters.html new file mode 100644 index 0000000..464d855 --- /dev/null +++ b/documentation/parameters.html @@ -0,0 +1,58 @@ +

Limiting function parameters

+

+ PHP has a mechanism to enforce function parameters types, and to accept + parameters either by reference or by value. In the examples above, we have + not yet used that mechanism yes: it is up to the function implementations + themselves to inspect the 'Parameters' object, and check if the + variables are of the right type. +

+

+ However, the 'Extension::add()' method takes a third optional parameter that + you can use to specify the number of parameters that are supported, whether + the parameters are passed by reference or by value, and what the type of + the parameters is: +

+

+


+#include <phpcpp.h>
+
+extern void example(Php::Parameters &params);
+
+extern "C" {
+    PHPCPP_EXPORT void *get_module() {
+        static Php::Extension myExtension("my_extension", "1.0");
+        myExtension.add("example", example, {
+            Php::ByVal("a", Php::Type::Numeric),
+            Php::ByVal("b", "ExampleClass"),
+            Php::ByRef("c", "OtherClass")
+        });
+        return myExtension.module();
+    }
+}
+
+

+

+ Above you see that we passed in additional information when we registered the + "example" function. We tell our extension that our function accepts three parameters: + the first parameter must be a regular number, while the other ones are object + instances of type "ExampleClass" and "OtherClass". In the end, your native C++ + "example" function will still be called with a Php::Parameters instance, but + the moment it gets called, you can be sure that the Php::Parameters object + will be filled with three members, and that two of them are objects of the + appropriate type, and that the third one is also passed by reference. +

+

Working with variables

+

+ Variables in PHP are non-typed. A variable can thus hold any possible type: + an integer, string, a floating point number, and even an object or an array. + C++ on the other hand is a typed language. In C++ an integer variable always + has a numeric value, and a string variable always hold a string value. +

+

+ When you mix native code and PHP code, you will need to convert the non-typed + PHP variables into native variables, and the other way round: convert native + variables back into non-typed PHP variables. The PHP-CPP library offers the + "Value" class that makes this a very simple task. +

+

+ \ No newline at end of file diff --git a/include/value.h b/include/value.h index d0079dc..b732616 100644 --- a/include/value.h +++ b/include/value.h @@ -683,6 +683,24 @@ protected: */ std::ostream &operator<<(std::ostream &stream, const Value &value); +/** + * Custom +=, -=, *=, /=, &= operators, to update integral types with a Php::Value + * + * This code looks complicated, it ensures that the operators are only + * overloaded for integral types (int, bool, etc) - and not for complex types + * (arrays, objects, etc) + */ +template ::value>::type* = nullptr> +X &operator+=(X &x, const Php::Value &value) { return x += (X)value; } +template ::value>::type* = nullptr> +X &operator-=(X &x, const Php::Value &value) { return x -= (X)value; } +template ::value>::type* = nullptr> +X &operator*=(X &x, const Php::Value &value) { return x *= (X)value; } +template ::value>::type* = nullptr> +X &operator/=(X &x, const Php::Value &value) { return x /= (X)value; } +template ::value>::type* = nullptr> +X &operator%=(X &x, const Php::Value &value) { return x %= (X)value; } + /** * End of namespace */ -- cgit v1.2.3