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| author | Richard M. Stallman | 2000-01-01 07:14:57 +0000 |
|---|---|---|
| committer | Richard M. Stallman | 2000-01-01 07:14:57 +0000 |
| commit | 3998eed0c79c6b68e94e8739fa1f1e08e8f09a69 (patch) | |
| tree | 0fc9c1ed8a1f43fd390fc0c510587338396d3bfe | |
| parent | 9b784e967651d58d80914c83f254ecd33a10682d (diff) | |
| download | emacs-3998eed0c79c6b68e94e8739fa1f1e08e8f09a69.tar.gz emacs-3998eed0c79c6b68e94e8739fa1f1e08e8f09a69.zip | |
*** empty log message ***
| -rw-r--r-- | lispref/lists.texi | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/lispref/lists.texi b/lispref/lists.texi index 58b1cfe4de8..4133114c3ea 100644 --- a/lispref/lists.texi +++ b/lispref/lists.texi | |||
| @@ -32,17 +32,21 @@ the whole list. | |||
| 32 | 32 | ||
| 33 | Lists in Lisp are not a primitive data type; they are built up from | 33 | Lists in Lisp are not a primitive data type; they are built up from |
| 34 | @dfn{cons cells}. A cons cell is a data object that represents an | 34 | @dfn{cons cells}. A cons cell is a data object that represents an |
| 35 | ordered pair. It holds, or ``refers to,'' two Lisp objects, one labeled | 35 | ordered pair. That is, it has two slots, and each slot @dfn{holds}, or |
| 36 | as the @sc{car}, and the other labeled as the @sc{cdr}. These names are | 36 | @dfn{refers to}, some Lisp object. One slot is known as the @sc{car}, |
| 37 | traditional; see @ref{Cons Cell Type}. @sc{cdr} is pronounced | 37 | and the other is known as the @sc{cdr}. (These names are traditional; |
| 38 | ``could-er.'' | 38 | see @ref{Cons Cell Type}.) @sc{cdr} is pronounced ``could-er.'' |
| 39 | 39 | ||
| 40 | A list is a series of cons cells chained together, one cons cell per | 40 | We say that ``the @sc{car} of this cons cell is'' whatever object |
| 41 | element of the list. By convention, the @sc{car}s of the cons cells are | 41 | its @sc{car} slot currently holds, and likewise for the @sc{cdr}. |
| 42 | the elements of the list, and the @sc{cdr}s are used to chain the list: | 42 | |
| 43 | the @sc{cdr} of each cons cell is the following cons cell. The @sc{cdr} | 43 | A list is a series of cons cells ``chained together,'' so that each |
| 44 | of the last cons cell is @code{nil}. This asymmetry between the | 44 | cell refers to the next one. There one cons cell for each element of |
| 45 | @sc{car} and the @sc{cdr} is entirely a matter of convention; at the | 45 | the list. By convention, the @sc{car}s of the cons cells hold the |
| 46 | elements of the list, and the @sc{cdr}s are used to chain the list: the | ||
| 47 | @sc{cdr} slot of each cons cell refers to the following cons cell. The | ||
| 48 | @sc{cdr} of the last cons cell is @code{nil}. This asymmetry between | ||
| 49 | the @sc{car} and the @sc{cdr} is entirely a matter of convention; at the | ||
| 46 | level of cons cells, the @sc{car} and @sc{cdr} slots have the same | 50 | level of cons cells, the @sc{car} and @sc{cdr} slots have the same |
| 47 | characteristics. | 51 | characteristics. |
| 48 | 52 | ||