NML:Elementary values
From GRFSpecs
Revision as of 15:38, 23 August 2022 by Andythenorth (talk | contribs)
Vehicles, Stations, Canals, Bridges, Towns, Houses, Industries (Tiles), Cargos, Airports+Tiles, Objects, Railtypes, Roadtypes, Tramtypes, Terrain
Elementary values in expressions are
| Element | Syntax (Python RE) | Description |
|---|---|---|
| Decimal number | [0-9]+ | one or more digits |
| Hexadecimal number | 0x[0-9A-Fa-f]+ | "0x" followed by one or more hexadecimal digits |
| Floating point number | [0-9]+\.[0-9]+ | a decimal number, a dot, and another decimal number. Only supported for some properties that expect a floating point number. |
| Identifier | [a-zA-Z_][a-zA-Z0-9_]* | a letter or underscore, optionally followed by more letters, digits, or underscore characters |
| String | "([^"\\]|\\.)*" | A double quote character, followed by zero or more characters, ending with another double quote character. A character in-between is any single character except a double quote or a back-slash ("\"). It can also be "\\", "\n", "\t", or "\[0-9A-Fa-f][0-9A-Fa-f]" (a back-slash followed by exactly two hexadecimal digits). |
| Setting | an Identifier |
The name of a GRF setting |
| Parameter | param[<num>] | Read/write the parameter with the given number. |
| Parameter from another GRF | param[<grfid>, <num>] | Read the value of a parameter of another grf |
| Unit | mph|km/h|m/s|hp|kW|hpI|hpM|tons|ton|kg |
See the section on units. |
You can combine those elementary values using operators like you're used to from other languages. The following operators are supported:
- Arithmetic operators: +, -, *, /, %
- Bitwise/logic operators: &, |, ^, &&, ||, <<, >>
- Comparison operators: ==, !=, <=, >=, <, >
Ternary operator
A ternary operator is provided (for integers only) in the form:
condition ? branch if true : branch if false
The ternary operator should be used with caution:
- it can be inefficient in certain cases as it executes both branches
- it is only safe for readonly operations (i.e. cannot be used with expressions like STORE_TEMP or STORE_PERM)
