Convert condition strings into lists of predicate vectors

Parse a character vector of conditions into a list of predicate vectors. Each element of the list corresponds to one condition. A condition is a string of predicates separated by commas and enclosed in curly braces, as produced by format_condition(). The function splits each string into its component predicates.

Usage

parse_condition(..., .sort = FALSE)

Arguments

...

One or more character vectors of conditions to be parsed.

.sort

Logical flag indicating whether the predicates in each result should be sorted alphabetically. Defaults to FALSE.

Value

A list of character vectors, where each element corresponds to one condition and contains the parsed predicates.

Details

If multiple vectors of conditions are provided via ..., they are combined element-wise. The result is a single list where each element is formed by merging the predicates from the corresponding elements of all input vectors. If the input vectors differ in length, shorter ones are recycled.

Empty conditions ("{}") are parsed as empty character vectors (character(0)).

See also

format_condition(), is_condition(), fire()

Author

Michal Burda

Examples

parse_condition(c("{a}", "{x=1, z=2, y=3}", "{}"))
#> [[1]]
#> [1] "a"
#> 
#> [[2]]
#> [1] "x=1" "z=2" "y=3"
#> 
#> [[3]]
#> character(0)
#> 

# Merge conditions from multiple vectors element-wise
parse_condition(c("{b}", "{x=1, z=2, y=3}", "{q}", "{}"),
                c("{a}", "{v=10, w=11}",    "{}",  "{r,s,t}"))
#> [[1]]
#> [1] "b" "a"
#> 
#> [[2]]
#> [1] "x=1"  "z=2"  "y=3"  "v=10" "w=11"
#> 
#> [[3]]
#> [1] "q"
#> 
#> [[4]]
#> [1] "r" "s" "t"
#> 

# Sorting predicates within each condition
parse_condition("{z,y,x}", .sort = TRUE)
#> [[1]]
#> [1] "x" "y" "z"
#>