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--- groimp-platform:xl-operators [2024/05/02 08:59] – TimOb
+++ groimp-platform:xl-operators [2025/01/10 15:08] (current) – [Pattern predicates] gaetan
@@ Line 1: / Line 1: @@
-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() | | |