https://github.com/tasxatzial/symbol-tables-list
https://github.com/tasxatzial/symbol-tables-list
Last synced: 3 months ago
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- Host: GitHub
- URL: https://github.com/tasxatzial/symbol-tables-list
- Owner: tasxatzial
- License: mit
- Created: 2020-10-05T21:42:09.000Z (about 5 years ago)
- Default Branch: master
- Last Pushed: 2023-04-17T17:32:26.000Z (over 2 years ago)
- Last Synced: 2025-03-02T15:49:47.082Z (7 months ago)
- Language: C
- Size: 13.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Symbol tables library
A simple library for [Symbol tables](https://en.wikipedia.org/wiki/Symbol_table). The implementation is based on **linked lists**.
The following functions are provided:
* SymTable_new(): Create a new table.
* Symtable_free(table): Delete table. No other functions should be used after this one.
* SymTable_getLength(table): Get the total number of keys.
* SymTable_put(table, key, value): Put (key, value) in the table only if key does not exist.
* SymTable_remove(table, key): Delete key from table.
* SymTable_contains(table, key): Check whether table has key.
* SymTable_get(table, key): Get the value associated with key.
* SymTable_map(table, function(key, new_value, extra_value), new_value): Apply a function to each value.
## Implementation
The symbol table is defined as an [opaque data type](https://en.wikipedia.org/wiki/Opaque_data_type).
C-strings are supported as keys and are stored directly in the table. Values can be of any type, therefore they should already be stored in a different data structure.
Internally the symbol tables are stored as linked lists. Operations like 'get', 'put', 'remove', 'contains' run in O(list_length) time.
For a more efficient implementation using Hash tables, see [symbol-table-hash](https://github.com/tasxatzial/symbol-table-hash).
## Compile
Build the library (functions declared in [symtable.h](src/symtable.h)):
```bash
make symtablelist.o
```
## Demo
Using the library is demonstrated in [runsymtab.c](src/runsymtab.c).
Build:
```bash
make list
```
The demo creates tables and inserts random (key, value) pairs. More specifically:
1. Values are always integers > 0.
2. Changing a value means adding 2 to it.
By default all operations are performed on one table. This can be altered by changing the NTABLES constant. There is also the option to show all intermediate results by changing the DEBUG constant to 1.
### Example
```bash
./list 10 5 abcde 2
```
will perform the following sequence of operations 2 times:
1. Insert 10 random (keys, values) with keys having 5 characters max from the alphabet 'abcde'.
2. Change the values of all keys.
3. Search for 10 random keys.
4. Delete 10 random keys.
## Profiling
'list' has been tested for memory leaks with [valgrind](https://valgrind.org/) and [AddressSanitizer](https://github.com/google/sanitizers/wiki/AddressSanitizer).