Documentation

- Started the new parser documentation.
2013-04-16 01:23:32 -04:00
parent 1641bcf592
commit 2232ff7a21
3 changed files with 284 additions and 0 deletions
--- a/doc/misc/parser/expressions.txt
+++ b/doc/misc/parser/expressions.txt
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+The expression evaluator allows powerful filters and modifications.
+
+There are four data types, just like UDAs:
+
+    string             project, description
+    date               due, wait ...
+    duration           recur
+    numeric            urgency
+
+There are several forms of literals:
+
+    rc.name            configuration
+    <dom>              task-specific data
+    <numeric>          numbers
+    <date>             either ISO-8601 or rc.dateformat dates
+    <duration>         either ISO-8601 or durations
+
+There are several supported operators:
+
+    +                  addition, concatenation
+    -                  subtraction, unary minus
+    *                  multiplication
+    /                  division
+    ( )                precedence
+    and or xor not !  logical operators
+    < <= > >=          relation operators
+    = !=               equality operators
+    ~ !~               match operators
+
+There are also helper operators to perform odd operations:
+
+    __hastag__         presence of a tag
+    __notag__          absence of a tag
+