https://github.com/graphitemaster/lambdapp

Anonymous functions in C
https://github.com/graphitemaster/lambdapp

anonymous-functions c lambda nested-functions

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Anonymous functions in C

• Host: GitHub
• URL: https://github.com/graphitemaster/lambdapp
• Owner: graphitemaster
• License: unlicense
• Created: 2014-06-07T19:51:19.000Z (over 10 years ago)
• Default Branch: main
• Last Pushed: 2020-06-15T23:30:11.000Z (over 4 years ago)
• Last Synced: 2024-04-14T02:19:52.229Z (6 months ago)
• Topics: anonymous-functions, c, lambda, nested-functions
• Language: C
• Size: 46.9 KB
• Stars: 245
• Watchers: 18
• Forks: 17
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
### Synposis

LambdaPP is a preprocessor for giving you anonymous functions in C.

### Examples

```

// for an example the table consists of a string keyed (room) of occupants

// stored in a linked list.

hashtable_t *table;

hashtable_foreach(table,

    lambda void(list_t *list) {

        list_foreach(list,

            lambda void(const char *occupant) {

                printf(">> %s\n", occupant);

            }

        );

    }

);

```

Closures are not supported by this system. It's important to note these are not

nested functions or blocks, for information on these please see the following

links.

[_Nested functions_](https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html)

[_Blocks_](http://clang.llvm.org/docs/Block-ABI-Apple.html)

This is a source translation that produces global functions and replaces instances

of the lambda with the literal.

### How it works

Given a lambda, a static function is created. The scope which implements the

lambda is replaced with a reference to the static function by taking it's address.

#### Example

```

(lambda void(void) { printf("Hello world"); })();

```

Would be translated to

```

static void lambda_0(void);

(&lambda_0)();

static void lambda_0(void) { printf("Hello world"); }

```

To better see how it works, here's the original example expanded:

```

hashtable_t *table;

static void lambda_0(list_t *list);

hashtable_foreach(table, &lambda_0);

static void lambda_1(const char *occupant);

static void lambda_0(list_t *list) {

    list_foreach(list, &lambda_1);

}

static void lambda_1(const char *occupant) {

    printf(">> %s\n", occupant);

}

```

### Diagnostics

LambdaPP inserts `#file` and `#line` directives into the source code such that

compiler diagnostics will still work.