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| author | Grzegorz Adam Hankiewicz <gradha@imap.cc> | 2014-06-22 17:22:23 +0200 |
|---|---|---|
| committer | Grzegorz Adam Hankiewicz <gradha@imap.cc> | 2014-06-22 17:22:53 +0200 |
| commit | 299e711a77f1c4e47c35f26735d7b5a3d1ec0571 (patch) | |
| tree | 5c3e466205620a87a2361e7e9f4d1df01b9891a9 /doc/backends.txt | |
| parent | 9c8ce45bcaedf24bc718e4c18f1b81ad81e36165 (diff) | |
| download | Nim-299e711a77f1c4e47c35f26735d7b5a3d1ec0571.tar.gz | |
Adds nimrod to backend examples.
Diffstat (limited to 'doc/backends.txt')
| -rw-r--r-- | doc/backends.txt | 70 |
1 files changed, 68 insertions, 2 deletions
diff --git a/doc/backends.txt b/doc/backends.txt index 9d57450dd..957a2d2ed 100644 --- a/doc/backends.txt +++ b/doc/backends.txt @@ -141,9 +141,75 @@ To wrap native code, take a look at the `c2nim tool <c2nim.html>`_ which helps with the process of scanning and transforming header files into a Nimrod interface. -Example in C. +C invocation example +~~~~~~~~~~~~~~~~~~~~ -Example in JS. +Create a ``logic.c`` file with the following content: + +.. code-block:: c + int addTwoIntegers(int a, int b) + { + return a + b; + } + +Create a ``calculator.nim`` file with the following content: + +.. code-block:: nimrod + + {.compile: "logic.c".} + proc addTwoIntegers(a, b: int): int {.importc.} + + when isMainModule: + echo addTwoIntegers(3, 7) + +With these two files in place, you can run ``nimrod c -r calculator.nim`` and +the Nimrod compiler will compile the ``logic.c`` file in addition to +``calculator.nim`` and link both into an executable, which outputs ``10`` when +run. Another way to link the C file statically and get the same effect would +be remove the line with the ``compile`` pragma and run the following typical +Unix commands:: + + $ gcc -c logic.c + $ ar rvs mylib.a logic.o + $ nimrod c --passL:mylib.a -r calculator.nim + +Just like in this example we pass the path to the ``mylib.a`` library (and we +could as well pass ``logic.o``) we could be passing switches to link any other +static C library. + + +JavaScript invocation example +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Create a ``host.html`` file with the following content: + +.. code-block:: + + <html><body> + <script type="text/javascript"> + function addTwoIntegers(a, b) + { + return a + b; + } + </script> + <script type="text/javascript" src="calculator.js"></script> + </body></html> + +Create a ``calculator.nim`` file with the following content (or reuse the one +from the previous section): + +.. code-block:: nimrod + + proc addTwoIntegers(a, b: int): int {.importc.} + + when isMainModule: + echo addTwoIntegers(3, 7) + +Compile the Nimrod code to JavaScript with ``nimrod js -o:calculator.js +calculator.nim`` and open ``host.html`` in a browser. If the browser supports +javascript, you should see the value ``10``. In JavaScript the `echo proc +<system.html#echo>`_ will modify the HTML DOM and append the string. Use the +`dom module <dom.html>`_ for specific DOM querying and modification procs. Backend code calling Nimrod |