SlothLang is an esoteric programming language by Aaron Goidel
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.
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: 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
.
Syntax: sloth * 2
Effect: pops the first two values off the stack and pushes their sum.
Stack: S, x, y -> S, x+y
Syntax: sloth * 3
Effect: pops the first two values off the stack and pushes their difference.
Stack: S, x, y -> S, x-y
Syntax: sloth * 4
Effect: pops the first two values off the stack and pushes their product.
Stack: S, x, y -> S, x*y
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
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
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
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
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
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.
Syntax: sloth * 10
Effect: pops an element off the stack and pushes it twice.
Stack: S, x -> S, x, x
SlothLang relies on the translation of a number of sloths to a numeric code in order to perform specific operations.
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 <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 |
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 \ |
0x02 |
Add |
0x03 |
Subtract |
0x04 |
Multiply |
0x05 |
Divide |
0x06 |
Compare \ |
0x07 |
Input \ |
0x08 |
Output \ |
0x09 |
GOTO \ |
0x0A |
DUP |
This project is licensed under the MIT License - see the LICENSE file for details
Mariana Ortiz Luna for the awesome logo
"Sloth Logo by Mariana Ortiz Luna "