diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 77 |
1 files changed, 59 insertions, 18 deletions
@@ -46953,31 +46953,55 @@ function does not interact with indentation. The column position tracking will be incorrect if byte and character output are mixed, affecting the placement of indentation. -Indentation mode takes on three numeric values, given by the three +Indentation mode takes on four numeric values, given by the four variables .codn indent-off , .codn indent-data , +.code indent-code and -.codn indent-code . -As far as stream output is concerned, the code and data modes behave +.codn indent-foff . +As far as stream output is concerned, the code and data modes +represented by +.code indent-code +and +.code indent-data +behave the same way: both represent the "indentation turned on" state. The difference between them influences the behavior of the .code width-check -function. This function isn't used by any stream output routines. -It is used by the object printing functions like +function. This function isn't used by any lower-level stream output +routines. It is used by the object printing functions like .code print and .code pprint to break up long lines. +The +.code indent-off +and +.code intent-foff +modes are also treated the same way by lower level stream output, +indicating "indentation turned off". The modes are distinguished +by +.code print +and +.code pprint +in the following way: +.code indent-off +is a "soft" disable which allows these object-printing routines +to temporarily turn on indentation while traversing aggregate objects. +Whereas the +.code indent-foff +("force off") value is a "hard" disable: the object-printing routines will not +enable indentation and will not break up long lines. -.coNP Variables @, indent-off @ indent-data and @ indent-code +.coNP Variables @, indent-off @, indent-data @ indent-code and @ indent-foff .desc These variables hold integer values representing output stream indentation modes. The value of .code indent-off is zero. -.coNP Functions @, get-indent-mode @ set-indent-mode and @ test-set-indent-mode +.coNP Functions @ get-indent-mode and @ set-indent-mode .synb .mets (get-indent-mode << stream ) .mets (set-indent-mode < stream << new-mode ) @@ -46989,7 +47013,6 @@ The .code get-indent-mode retrieves the current indent mode of .metn stream . - The .code set-indent-mode function sets the indent mode of @@ -46998,6 +47021,23 @@ to .meta new-mode and returns the previous mode. +Note: it is encouraged to save and restore the indentation mode, +and in a way that is exception safe. +If a block of code sets up indentation on a stream such as +.code *stdout* +and is terminated by an exception, the indentation will remain in +effect and affect subsequent output. The +.code with-resources +macro or +.code unwind-protect +operator may be used. + +.coNP Functions @ test-set-indent-mode and @ test-neq-set-indent-mode +.synb +.mets (test-set-indent-mode < stream < compare-mode << new-mode ) +.mets (test-neq-set-indent-mode < stream < compare-mode << new-mode ) +.syne +.desc The .code test-set-indent-mode function sets the indent mode of @@ -47009,16 +47049,17 @@ its current mode is equal to .metn compare-mode . Whether or not it changes the mode, it returns the previous mode. -Note: it is encouraged to save and restore the indentation mode, -and in a way that is exception safe. -If a block of code sets up indentation on a stream such as -.code *stdout* -and is terminated by an exception, the indentation will remain in -effect and affect subsequent output. The -.code with-resources -macro or -.code unwind-protect -operator may be used. +The +.code test-neq-set-indent-mode +only differs in that it sets +.meta stream +to +.meta new-mode +if, and only if, +the current mode is +.B not +equal to +.metn compare-mode . .coNP Functions @, get-indent @ set-indent and @ inc-indent .synb |