Standard Library

MVM Standard Library Overview

The MVM standard library provides reusable functions to enhance MVM programs. These functions handle common tasks and offer higher-level abstractions. All functions use the stack for arguments and return values. The library is organised into modules, each focusing on a specific area of functionality.

Library Modules

The standard library is structured into the following modules:

String Functions

This module provides string manipulation functions. Functions operate on null-terminated strings, and memory management is handled automatically. The available functions are:

• strcmp: Compares two strings lexicographically. Returns 1 if equal, 0 otherwise.
• strcat: Concatenates two strings. Returns the address of the new string.
• strcpy: Copies a string from a source to a destination. Returns the destination address.
• strlen: Returns the length of a string.

Array Functions

This module provides array-related functions. The functions support array creation, access, and manipulation. Arrays created with createArray can be cleared using clean.array. The available functions are:

• create: Creates a new array. Returns the address of the new array.
• get: Gets an element from an array. Returns the element's value.
• size: Returns the size of an array.

Math Functions

This module contains standard mathematical functions. For floating-point functions, operands must be of the same type. The functions are:

• min: Returns the smaller of two values.
• max: Returns the larger of two values.
• inc: Increments a value by 1.
• dec: Decrements a value by 1.
• neg: Negates a value.
• sq: Squares a value.

Clean Functions

This module handles clearing parts of memory automatically. The functions are

• array: Clears an array.
• string: Clears a string.

IO Functions

This module handles simple I/O operations, including console input and output. The functions are:

• println: Prints a string to the console with a newline.
• readln: Reads a line of input from standard input and returns its address.

System Functions

This module is responsible for system-related functions The functions are

• exit: Exits the program

Conversion Functions

This module contains data type conversion functions. The available functions are:

• asciiToInt: Converts an ASCII character to its integer representation.
• strtoint: Converts a string to a, long.
• findFirstString: Finds the first occurrence of a character within a string.

Calling Standard Library Functions

Standard library functions are called using the CALL instruction:

call strings.strlen  // Call the strlen function

Arguments are passed in F registers (F1, F2, etc.), and the return value (if any) is pushed onto the stack.

Further Information

Refer to the Standard Library Table for detailed information on each function, including argument types and return values.