diff options
Diffstat (limited to 'doc/concepts/expressions.org')
| -rw-r--r-- | doc/concepts/expressions.org | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/doc/concepts/expressions.org b/doc/concepts/expressions.org index 5b7e2f2c..2dff612a 100644 --- a/doc/concepts/expressions.org +++ b/doc/concepts/expressions.org @@ -121,7 +121,8 @@ expression. ****** Sequential case distinction on arbitrary values: ~"case*"~ If the key ~"case"~ is present, it has to be a list of pairs. In this -case, the key ~"expr"~ is evaluated. The result of that evaluation +case, the key ~"expr"~ is evaluated. It is an error if that evaluates +to a name-containg value. The result of that evaluation is sequentially compared to the evaluation of the first components of the ~"case"~ list until an equal value is found. In this case, the evalaution of the second component of the pair is the value of @@ -188,7 +189,8 @@ those) argument(s) to obtain the final result. ***** Unary functions -- ~"nub_right"~ The argument has to be a list. The result is the +- ~"nub_right"~ The argument has to be a list. It is an error if that list + contains (directly or indirectly) a name. The result is the input list, except that for all duplicate values, all but the rightmost occurence is removed. @@ -268,11 +270,14 @@ those) argument(s) to obtain the final result. conflicts can also occur in non-flat staging if two keys are different as strings, but name the same path (like ~"foo.txt"~ and ~"./foo.txt"~), and are assigned different values. + It also is an error if the values for keys in conflicting positions + are name-containing. ***** Binary functions - ~"=="~ The result is ~true~ is the arguments are equal, ~false~ - otherwise. + otherwise. It is an error if one of the arguments are name-containing + values. - ~"concat_target_name"~ This function is only present to simplify transitions from some other build systems and normally not used @@ -325,4 +330,5 @@ that evaluation included in the error message presented to the user. - ~"disjoint_map_union"~ Like ~"map_union"~ but it is an error, if two (or more) maps contain the same key, but map it to - different values. + different values. It is also an error if the argument is a + name-containing value. |