SlothLang

SlothLang is an esoteric programming language by Aaron Goidel

Features

• Write code in a highly efficient and easy to read language
• Slothy sloths are slothy

Tech

SlothLang is parsed and executed in C.

And of course the code behind the SlothLang VM itself is open source and can be found on GitHub.

Usage

A Sloth program is parsed as new-line deliminated instructions. Every line starts a new instruction at 0x00. Each occurrence of the word sloth on a line increases the instruction code by one. At the end of each line the resulting instruction code is pushed and the next line is read.

Since a Sloth command is generally based on the number of times the word sloth appears in a row, the syntax will be documented as a multiplication. For example the documentation sloth * 3 means sloth sloth sloth in Sloth code.

To save time and effort, there are a few commands which do not follow the scheme outlined above. These will be outlined below.

Note: the and operator is used to separate arguments.

Syntax and Effects

Exit

Syntax: nap
Effect: will terminate the execution of the program and return the top element from the stack.
NOTE: every Sloth file must end in nap.

Add

Syntax: sloth * 2
Effect: pops the first two values off the stack and pushes their sum.
Stack: S, x, y -> S, x+y

Subtract

Syntax: sloth * 3
Effect: pops the first two values off the stack and pushes their difference.
Stack: S, x, y -> S, x-y

Multiply

Syntax: sloth * 4
Effect: pops the first two values off the stack and pushes their product.
Stack: S, x, y -> S, x*y

Divide

Syntax: sloth * 5
Effect: pops the first two values off the stack and pushes their quotient.
Stack: S, x, y -> S, x/y
NOTE: Division in SlothLang is integer division, meaning divide will always round fractions down. e.g. 3/2 = 1

Compare <c>

Syntax: sloth * 6 and sloth * c

Notice that the compare instruction requires an argument. The number of sloths after the and will determine which comparison should be made. See Comparison Codes for reference.

Effect: pops the first two values off the stack and pushes the truthiness of a comparison between them.
Stack: S, x, y -> S, 1 if true 0 if false

Input <t>

Syntax: sloth * 7 and sloth * t

The input instruction takes a type code to determine what kind of data is being read. See Type Codes for reference.

Effect: reads in either an integer or an ASCII character from standard in.
Stack: S -> S, x

Output <t>

Syntax: sloth * 8 and sloth * t

The output instruction takes a type code to determine what kind of data is being displayed. See Type Codes for reference.

Effect: pops the top value off the stack and writes it to standard out.
Stack: S, x -> S

GOTO <n>

Syntax: sloth * 9 and sloth * n

The GOTO instruction takes a number of sloths as the destination if the result is true.

Effect: pops the top value off the stack, if the value is 1, the program counter is set to specified instruction, else continues as normal.
Stack: S, x -> S

Push <i>

Syntax: slothy sloth * i
Effect: pushes the integer value of the number of sloths following slothy onto the stack.
Stack: S -> S, x
Example: slothy sloth sloth sloth pushes 3 onto the stack.

Duplicate

Syntax: sloth * 10
Effect: pops an element off the stack and pushes it twice.
Stack: S, x -> S, x, x

Operation, Comparison, and Type Codes

SlothLang relies on the translation of a number of sloths to a numeric code in order to perform specific operations.

Comparison Codes

The Compare function uses <c> sloths in order to select what kind of comparison is being made.

Comparison Code	Operation
0x01	x == y
0x02	x != y
0x03	x < y
0x04	x <= y
0x05	x > y
0x06	x >= y

Type Codes

Type Codes <t> are used in the Input and Output instructions in order to determine what kind of data is being read or written.

Type Code	Type of I/O
0x01	A signed integer value
0x02	A single ASCII character

Operation Codes

Sloth code is read in by the SlothVM as bytecode. The following is the bytecode for each SlothLang instruction.

Byte Code	Name
0x00	Exit
0x01	Push <i>
0x02	Add
0x03	Subtract
0x04	Multiply
0x05	Divide
0x06	Compare <c>
0x07	Input <t>
0x08	Output <t>
0x09	GOTO <o>
0x0A	DUP

License

This project is licensed under the MIT License - see the LICENSE file for details

Thanks To

• Mariana Ortiz Luna for the awesome logo