Functions and Operators

Function syntax

All built-in standard library functions are reflected as functions in e.

1. e.str_upper(e.str("hello"));
2. // str_upper("hello")

4. e.op(e.int64(2), '+', e.int64(2));
5. // 2 + 2

7. const nums = e.set(e.int64(3), e.int64(5), e.int64(7))
8. e.op(e.int64(4), 'in', nums);
9. // 4 in {3, 5, 7}

11. e.math.mean(nums);
12. // math::mean({3, 5, 7})

Prefix operators

Unlike functions, operators do not correspond to a top-level function on the e object. Instead, they are expressed with the e.op function.

Prefix operators operate on a single argument: OPERATOR <arg>.

1. e.op('not', e.bool(true));      // not true
2. e.op('exists', e.set('hi'));    // exists {'hi'}
3. e.op('distinct', e.set('hi', 'hi'));    // distinct {'hi', 'hi'}

Infix operators

Infix operators operate on two arguments: <arg> OPERATOR <arg>.

1. e.op(e.str('Hello '), '++', e.str('World!'));
2. // 'Hello ' ++ 'World!'

Ternary operators

Ternary operators operate on three arguments: <arg> OPERATOR <arg> OPERATOR <arg>. Currently there’s only one ternary operator: the if else statement.

1. e.op(e.str('😄'), 'if', e.bool(true), 'else', e.str('😢'));
2. // 😄 if true else 😢