diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 19 |
1 files changed, 18 insertions, 1 deletions
@@ -29003,9 +29003,10 @@ Rather it may be substituted by one kind of form when it is treated as a pure value, and another kind of form when it is treated as a place. -.coNP Operator @ tree-bind +.coNP Operators @ tree-bind and @ mac-param-bind .synb .mets (tree-bind < macro-style-params < expr << form *) +.mets (mac-param-bind < context-expr < macro-style-params < expr << form *) .syne .desc The @@ -29031,6 +29032,22 @@ structural mismatch between the parameters and the value of One way to avoid this exception is to use .codn tree-case . +The +.code mac-param-bind +operator is similar to +.code tree-bind +except that it takes an extra argument, +.metn context-expr. +This argument is an expression which is evaluated. It is expected to +evaluate to a compound form. If an error occurs during binding, the error +diagnostic message is based on information obtained from this form. +By contrast, the +.code tree-bind +operator's error diagnostic refers to the +.code tree-bind +form, which is cryptic if the binding is used for the implementation +of some other construct, hidden from the user of that construct. + .coNP Operator @ tree-case .synb .mets (tree-case < expr >> {( macro-style-params << form *)}*) |