6.24.3 Miscellaneous output ¶

cr ( –  ) core “c-r”

Output a newline (of the favourite kind of the host OS). Note that due to the way the Forth command line interpreter inserts newlines, the preferred way to use cr is at the start of a piece of text; e.g., cr ." hello, world".

space ( –  ) core

Display one space.

spaces ( u –  ) core

Display u spaces.

out ( – addr  ) gforth-1.0

Addr contains a number that tries to give the position of the cursor within the current line on the user output device: It resets to 0 on cr, increases by the number of characters by type and emit, and decreases on backspaces. Unfortunately, it does not take into account tabs, multi-byte characters, or the existence of Unicode characters with width 0 and 2, so it only works for simple cases.

.\" ( compilation ’ccc"’ – ; run-time –  ) gforth-0.6 “dot-backslash-quote”

Like .", but translates C-like \-escape-sequences (see S\").

." ( compilation ’ccc"’ – ; run-time –  ) core “dot-quote”

Compilation: Parse a string ccc delimited by a " (double quote). At run-time, display the string. Interpretation semantics for this word are undefined in standard Forth. Gforth’s interpretation semantics are to display the string.

.( ( compilation&interpretation ’ccc<close-paren>’ –  ) core-ext “dot-paren”

Compilation and interpretation semantics: Parse a string ccc delimited by a ) (right parenthesis). Display the string. This is often used to display progress information during compilation; see examples below.

If you don’t want to worry about whether to use .( hello) or ." hello", you can write "hello" type, which gives you what you usually want (but is less portable to other Forth systems).

As an example, consider the following program:

.( text-1)     \ prints "text-1"
: my-word
  ." text-2"
  .( text-3)   \ prints "text-3"
  "text-4" type
;

my-word        \ prints "text-2text-4"

." text-5"     \ prints "text-5"
"text-6" type  \ prints "text-6"

If you want to understand why this code behaves this way, the explanations for this concrete example are:

• Messages text-1 and text-3 are displayed because .( is an immediate word; it behaves in the same way whether it is used inside or outside a colon definition (see Interpretation and Compilation Semantics).
• Message text-2 is not displayed during the definition of my-word, because the text interpreter performs the compilation semantics for .". Later the interpretation semantics of my-word are performed, and they perform the run-time semantics of .".
• Message text-4 is not displayed during the definition of my-word, because "text-4" (see rec-string, translate-string) performs the compiling run-time for the string, which compiles the interpreting run-time (see Defining recognizers) into my-word, and type compiles the interpretation/execution semantics of type into my-word. Later the interpretation semantics of my-word are performed, and they perform the compiled interpreting run-time and interpretation semantics.
• Message text-5 is displayed because of Gforth’s added interpretation semantics for .".
• Message text-6 is displayed because "text-6" type is interpreted.