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groimp-platform:xl-operators [2024/05/02 06:59] – TimObgroimp-platform:xl-operators [2025/01/10 14:08] (current) – [Pattern predicates] gaetan
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-XL-Operators are designed to simplify the usage of XL queries and rewriting rules. Moreover these operators can improve the performance of a query due to there deep integration into the model. +===== Production operators =====
-In the following the operators a separated into Analytical and selection operators to either get a value for analysis or a node/ a collection of nodes for rewriting.+
  
-====== Analytical Operators ======+Production operators are operators that can be used in a production statement.
  
-| Command | description | example | +==== Edge operators ====
-| min((*//query//*)[//value//]) | returns the smallest value | min((*F*)[length]) | +
-| max((*//query//*)[//value//]) | returns the largest value | max((*F*)[length]) | +
-| sum((*//query//*)[//value//]) | calculate the sum of the values | sum((*F*)[length]) | +
-| prod((*//query//*)[//value//]) | unclear | prod((*F*)[length]) | +
-| count((*//query//*) )| returns the number of pattern matching the query | count((*F*) ) | +
-| empty((*//query//*) ) | returns true if no pattern matches the query | empty((*F*) ) | +
-| forall((*//query//*)[//value//]//condition//) | checks if a condition is true for the all results of the query |forall((*f:F*)[length]==1) |   +
-| exist((*//query//*)[//value//]//condition//) | checks if a condition is true for at least one result of the query |exist((*f:F*)[length]==1) |+
  
- +| whitespace | add node and connect with previous node, if any, by a successor edge | 
- +| > | connect node with previous by a successor edge | 
-====== Selection Operators ====== +| < | connect node with previous by a reverse successor edge | 
- +| %%<->%% | connect node with previous by successor edges in both directions | 
-|command | description|example| +| %%---%% | connect node with previous by a successor edge if there does not yet exist such an edge in either direction | 
-| first() | | | +| %%+>%%, %%<+%%, %%<+>%%, %%-+-%% | as before, but branch instead of successor edges | 
-| last() | | | +| %%/>%%, %%</%%, %%</>%%, %%-/-%% | as before, but refinement instead of successor edges | 
-|selectWhere()|  |  | +| %%-e->%%, %%<-e-%%, %%<-e->%%, %%-e-%% with an int-valued expression e | as before, but edges of type e instead of successor edges | 
-|selectWhereMin()|  |  | +| %%-n->%% with a node-valued expression n | create a compound edge with n encoding the edge data | 
-|selectWhereMax()|  |  | +| %%<-n-%% with a node-valued expression n | as before, but reverse direction | 
-|selectRandomly()|  |  | +| [, ] | define the starts and the end of a branch connected subgraph |
- +
- +
-====== Other ====== +
- +
-|command | description|example| +
-| array() | | |  +
-| string() | | |+
  
  
groimp-platform/xl-operators.1714633148.txt.gz · Last modified: 2024/05/02 06:59 by TimOb