Numbers in langur are decimal floating point. Langur uses Mike Cowlishaw's decimal C library, via the Go wrapper library github.com/rin01/decnum. Conceivably, it should be possible to use the DFPAL library in the same manner.
Numbers in base 10 may be specified without qualification, such as 100 or 123.456.
Number literals may use underscores for visual clarity (such as 3_000_000), but cannot start with an underscore.
E-notation may be used, but always requires a + or - after the e.
Rounding defaults to round-half-even. Later revisions will likely allow you to specify a different rounding mode.
Numbers may use basex notation, such as 16xFF or 2x1010_0010 or -4x123.
Any base from 2 to 36 may be used, using the ASCII alphabet for digits higher than 9.
At this time, basex notation is only available for integers.
| + | add |
| - | subtract |
| x | multiply |
| / | divide |
| \ | integer divide |
| // | remainder (not "modulus") |
| ^ | exponent (right-associative) |
| ^/ | root (right-associative) |
Also see the operators page.
The following constants are available by using the keyword.
| pi | Archimedes' constant |
| phi | the Golden Ratio |
| e | Euler's number |
| n2 | natural logarithm of 2 |
| n10 | natural logarithm of 10 |
So, to calculate the circumference of a circle with radius of 7, you could use the following.
2 x pi x 7 # result == 43.98229715025710533847700736591304