Jelly has a minimal syntax focusing on code clarity. Whitespace is insignificant but newlines are as only one statement is allowed per line.
Jelly only has one literal type - a double-precision floating point number (eg: 4, 5.2, or -2.34).
Similar to most C-like languages, a variable initialisation has a variable name, an equals symbol, and then an expression which evaluates to a value.
variable = 3 + 6
Variables mutations are structurally similar to their initialisation, but they use '=>' rather than '='.
variable => variable - 1
A function is declared with the function name and then the parameters in angled brackets, separated by commas. The function ends with the 'end' keyword. A tilde '~' indicates the result of the following expression will be returned.
Square<x>
~x * x
end
Omitting the expression after the tilde will return NaN. If a method ends without returning it will also return NaN.
Divide<top, bottom>
if bottom == 0
~
end
~top / bottom
end
Operations are currently parsed right-to-left as it was the easiest way to parse it. If precedence is needed, use parenthesis to explicitly determine the order of operations.
| Operator | Use |
|---|---|
| + | Add the LHS and RHS |
| - | Subtract the RHS from the LHS, or the negative value of the following term |
| * | Multiply the LHS and RHS |
| / | Divide the LHS by the RHS |
| % | The remainder after dividing the LHS from the RHS |
| == | 1 if the LHS and RHS are equal, 0 otherwise |
| != | 0 if the LHS and RHS are equal, 1 otherwise |
| << | 1 if the LHS is less than the RHS, 0 otherwise |
| >> | 1 if the LHS is greater than the RHS, 0 otherwise |
| <= | 1 if the LHS is less than or equal to the RHS, 0 otherwise |
| >= | 1 if the LHS is greater than or equal to the RHS, 0 otherwise |
| | | The absolute value of the term inside (eg: |-4|) |
A condition is an expression which is used in a block to determine whether to run it or not.
A zero value is equivalent to false, everything else is considered true.
The unary operator ! is used before a condition to 'flip' it; if it is true, it will become false, and vice-versa.
The keywords if, elif, and else are used to start a conditional block.
if and elif blocks have a condition after the keyword, if it is true, it will execute that block.
Each block ends with the end keyword.
if x == 2
@ If x is 2
end
elif x == 4
@ If x is 4
end
elif x == 5
@ If x is 5
end
else
@ If x is not 2, 4, or 5
end
A loop is declared with the loop keyword, and is followed by a condition.
While the condition evaluates to true, the loop body will execute over and over again.
loop x >> 100
WriteLine<x>
x => RandomIntBetween<0, 1000>
end
An '@' symbol denotes that the rest of the line will not be processed by the compiler and can be used to comment.
A semicolon at the end of a line denotes that the statement continues on to the next line.
xSquared = x * ;
x
is exactly the same as
xSquared = x * x
This is useful in cases where lines might be very long and it would be more readable to write it over several.