Syntax reference

A LS script is executed sequentially from top to bottom. The script is composed only of top-level cases.

• Concepts
  • Slots
  • Truthy values
• Comments
• Case blocks
  • Conditional cases
  • Unconditional cases
• Expressions
  • Number literals
  • Slot accessors
  • List expression
  • Operators
    • Binary operators
    • Unary operators
    • Explicit operators
• Statements
  • Assignment
  • If statements
  • update statement

Concepts

Slots

Slots represent a machine's input and output, and can be raw or indexed. The number inside an indexer will always be treated as a decimal number.

Truthy values

A value will be considered "true" if it is greater than 0. If you instead want to check for a value equal to 1, use the equality operator (x == 1)

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Comments

Comments can be started with a # anywhere on a line.

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Case blocks

Conditional cases

Only executed if the condition evaluates to a truthy value.

when <expression>
    ...
end

Unconditional cases

Will be executed regardless of the machine's state.

any
    ...
end

once
    ...
end

• any cases will always be executed, regardless of the machine's state
• once cases will only be executed once (up to machine implementation, usually on first update)

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Expressions

Number literals

LogicScripts distinguishes between binary and decimal numbers through the use of a suffix apostrophe ('). All decimal numbers must be suffixed, even if they contain digits other than 0 and 1, to prevent mistakes and confusion.

1010
123'
123 # Invalid, throws warning

Slot accessors

Only input (in) and memory (mem) slots can be used as expressions.

in
in[123]

List expression

Accepts multiple expressions in list form and combines them into a single number

(expr1, expr2, expr3, ...)

Operators

All operators operate on numbers.

Binary operators (binary as in two operands)

• Bitwise operators:
  • AND &
  • OR |
• Arithmetic operators:
  • Add +
  • Subtract -
  • Multiply *
  • Divide /
• Comparison operators:
  • Equals ==
  • Greater >
  • Greater or equal >=
  • Lesser <
  • Lesser or equal <=

Unary operators

• Negation !
  • Will negate all bits of a number

Explicit operators

• Aggregation operators:
  • Will combine a number's bits into a single bit
  • AND and
    • and(1010) == 0
  • OR or
    • or(1010) == 1
  • Sum of bits sum
    • sum(110011) == 4
• Truncate trunc
  • Will remove a number's zero-bits on the left side
  • trunc(00011) == 11

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Statements

Contained inside cases or other statements.

Assignment

Assign a value to a slot. Only output (out) and memory (mem) slots can be assigned to.

out = 1010
mem[1] = 1

If statements

Will execute a block of statements if a condition is evaluated to a truthy value.

if <expression>
    ...
end

if <expression>
    ...
else
    ...
end

update statement

This statement's functionality will vary between machine implementations, and it will only be available if the machine supports it (by implementing the IUpdatableMachine interface).

In Logic World this statement will cause the component it's running on to be updated on the next tick.

update