diff options
| -rw-r--r-- | txr.1 | 32 |
1 files changed, 24 insertions, 8 deletions
@@ -36728,7 +36728,7 @@ one specifies the result of .coNP Functions @ source-loc and @ source-loc-str .synb .mets (source-loc << form ) -.mets (source-loc-str << form <> [ alternative ]) +.mets (source-loc-str < form <> [ alternative ]) .syne .desc These functions map an expression in a \*(TX program to the file name and @@ -36745,21 +36745,37 @@ The .code source-loc-str function formats the information as a string. +Forms which were parsed from a file have source location info +tracking to their origin in that file. Forms which are the result +of macro-expansion are traced to the form whose evaluation produced +them. That is to say, they inherit that form's source location info. + +More precisely, when a form is produced by macro-expansion, +it usually consists of material which was passed to the macro as arguments, +plus some original material allocated by the macro, and possibly +literal structure material which is part of the macro code. +After the expansion is produced, any of its constituent material +which already has source location info keeps that info. Those nodes +which are newly allocated by the macro-expansion process inherit +their source location info from the form which yields the expansion. + If .meta form is not a piece of the program source code that was constructed by the -\*(TX parser, then +\*(TX parser or by a macro, and thus it was neither attributed with +source location info, nor has it inherited such info, then .code source-loc returns -.codn nil , -and, in the absence of the +.codn nil . + +In the same situation, and if its .meta alternative -argument, +argument is missing, the .code source-loc-str -returns a string whose text says that source location is not available, -otherwise it returns the +returns a string whose text conveys that the source location is not +available. If the .meta alternative -argument. +argument is present, it is returned. .coNP Function @ rlcp .synb |