SCM

4.2: Miscellaneous Procedures

Function: try-load filename

If the string filename names an existing file, the try-load procedure reads Scheme source code expressions and definitions from the file and evaluates them sequentially and returns #t. If not, try-load returns #f. The try-load procedure does not affect the values returned by current-input-port and current-output-port.

Variable: *load-pathname*

Is set to the pathname given as argument to load, try-load, and dyn:link (see Compiling And Linking). *load-pathname* is used to compute the value of program-vicinity.

Function: line-number

Returns the current line number of the file currently being loaded.

Function: eval obj

Alias for eval.

Function: eval-string str

Returns the result of reading an expression from str and evaluating it. eval-string does not change *load-pathname* or line-number.

Function: load-string str

Reads and evaluates all the expressions from str. As with load, the value returned is unspecified. eval-string does not change *load-pathname* or line-number.

Function: vector-set-length! object length

Change the length of string, vector, bit-vector, or uniform-array object to length. If this shortens object then the remaining contents are lost. If it enlarges object then the contents of the extended part are undefined but the original part is unchanged. It is an error to change the length of literal datums. The new object is returned.

Function: copy-tree obj

Function: @copy-tree obj

See copy-tree. This extends the SLIB version by also copying vectors. Use @copy-tree if you depend on this feature; copy-tree could get redefined.

Function: acons obj1 obj2 obj3

Returns (cons (cons obj1 obj2) obj3). The expression (set! a-list (acons key datum a-list)) adds a new association to a-list.

Function: terms

This command displays the GNU General Public License.

Function: list-file filename

Displays the text contents of filename.

Procedure: print arg1 ...

Print writes all its arguments, separated by spaces. Print outputs a newline at the end and returns the value of the last argument.