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

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