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Construct a conditional expression node for multimod AST

Source: R/ast-classes.R
ast_when.Rd

This function constructs a conditional expression node of type "when", representing GAMS-style conditional terms using the $ operator, if ... else ... statements in Julia/JuMP, if ... in ... in Python/Pyomo, etc.

Usage

ast_when(condition, then, otherwise = NULL, ...)

Arguments

condition

The condition to check, must be an AST node.

then

The expression to evaluate if the condition is true (usually the left-hand side).

otherwise

Optional expression to evaluate if the condition is false. This part is not available in GAMS $ statements, but is useful for other languages.

...

Additional fields stored on the node (passed to new_ast()).

Value

An object of class ast and subclass when.

Examples

ast_when(
  condition = ast_symbol("i_active(i)"),
  then = ast_variable("x", c("i"))
)
#> <AST when> 
#>   condition:
#> <AST symbol> i_active(i)
#>   then :
#> <AST variable> x
#>   dims:  [i] 
#>   otherwise :
#> NULL