# Assembler directives (ivss)

**Assembler directives** control object construction instead of requesting processor operations. ivss recognizes dot-prefixed statements for sections, data, symbols, constants, and termination:

```asm
.global answer
.equ initial, 42
.section my_data
answer:
    .word initial
    .skip 4
.end
```

`.global` exports the symbol, `.equ` defines an absolute value, and `.section` chooses the output section. `.word` emits a four-byte value; `.skip` appends four zero bytes. `.end` stops source processing. These directives do not become separate instructions for the emulator to execute.

The implementation dispatches each recognized directive to a handler. Data directives modify the current section's buffer. Symbol directives update symbol metadata, and `.equ` expressions are saved for evaluation after source processing.

This timing permits an expression to use labels discovered later in the input. It does not provide arbitrary compile-time programming: expressions use the assembler's supported arithmetic and symbol evaluation rules. [[ivss-constant-expressions|Constant expressions]] and [[ivss-data-allocation|data allocation]] explain these two parts separately.

Source: [asembler.c](https://github.com/yanevskiv/ivss/blob/main/src/asembler.c).