Table Of Contents

Expression Syntax

Last Modified: June 10, 2021

Use expression syntax similarly to the syntax used in text-based programming languages.

Your expression syntax must conform to the allowed functions and operator precedence in the Expression component of the Property Browser.

The expression syntax is summarized below using Backus-Naur Form (BNF notation). The summary includes non-terminal symbols: identifier, number, array-size, floating-point-type, integer-type, left-hand-side, assignment-operator, and function.
spd-note-note
Note  

Italicized symbols are terminal symbols given exactly as how you should reproduce them. The symbol # denotes any number of the term following it.

assignment:
  • expression
  • left-hand-side assignment-operator assignment
expression:
  • expression binary-operator expression
  • unary-operator expression
  • expression unary-operator
  • expression ? expression : expression
  • ( expression )
  • identifier
  • constant
  • function-name ( argument-list )
left-hand-side:
  • identifier
  • identifier array-subscription
array-subscription:
  • [assignment]
assignment-operator: one of
  • = += –= *= /= >>= <<= &= ^= |= %= **=
binary-operator: one of
  • + * / ^ != == > < >= <= >> << && || & | % **
unary-operator: one of
  • ! ++ –– ~
argument-list:
  • expression
  • expression , argument-list
constant:
  • pi
  • true
  • false
  • number
non-digit: one of
  • _ a~z A~Z
digit: one of
  • 0 1 2 3 4 5 6 7 8 9
nonzero-digit: one of
  • 1 2 3 4 5 6 7 8 9
binary-digit: one of
  • 0 1
hex-digit: one of
  • 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
identifier:
  • non-digit [non-first-character]
non-first-character:
  • non-digit [non-first-character]
  • digit [non-first-character]
number:
  • integer-constant
  • float-constant
integer-constant:
  • decimal-constant
  • binary-constant
  • hex-constant
decimal-constant:
  • nonzero-digit #digit
binary-constant:
  • 0b #binary-digit
  • 0B #binary-digit
hex-constant:
  • 0x #hex-digit
  • 0X #hex-digit
float-constant:
  • fraction exponent-part
  • decimal-constant exponent-part
fraction:
  • #digit . digit #digit
exponent-part:
  • e [sign] #digit
  • E [sign] #digit
sign: one of
  • + -

Recently Viewed Topics