2.6. Sharpsign
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## 2.6. Sharpsign [sec_2-4-8]

Reader macros are also defined for the following:

Additional reader macros

#,
  load-time evaluation, kept despite the [ANSI CL standard] issue SHARP-COMMA-CONFUSION:REMOVE.
#Y
  compiled `FUNCTION` objects and input `STREAM`'s `EXT:ENCODING`s
#""
  `PATHNAME`: `#"test.lisp"` is the value of `(`PATHNAME` "test.lisp")`

### 2.6.1. Sharpsign Backslash [sec_2-4-8-1]

#\Code allows input of characters of arbitrary code: e.g., #\Code231 reads as the character `(`CODE-CHAR` 231)`.

### 2.6.2. Sharpsign Less-Than-Sign [sec_2-4-8-20]

This is the list of objects whose external representation cannot be meaningfully read in:

Unreadable objects

`#<`type` ...>`
  all `STRUCTURE-OBJECT`s lacking a keyword constructor
`#<ARRAY `type` `dimensions`>`
  all `ARRAY`s except `STRING`s, if `*PRINT-ARRAY*` is `NIL`
`#<SYSTEM-FUNCTION `name`>`
  built-in function written in C
`#<ADD-ON-SYSTEM-FUNCTION `name`>`
  module function written in C
`#<SPECIAL-OPERATOR `name`>`
  special operator handler
`#<COMPILED-CLOSURE `name`>`
  compiled function, if `CUSTOM:*PRINT-CLOSURE*` is `NIL`
`#<CLOSURE `name` ...>`
  interpreted function
`#<FRAME-POINTER #x...>`
  pointer to a stack frame
`#<DISABLED POINTER>`
  frame pointer which has become invalid on exit from the corresponding `BLOCK` or `TAGBODY`
`#<...STREAM...>`
  `STREAM`
`#<PACKAGE `name`>`
  `PACKAGE`
`#<HASH-TABLE #x...>`
  `HASH-TABLE`, if `*PRINT-ARRAY*` is `NIL`
`#<READTABLE #x...>`
  `READTABLE`
`#<SYMBOL-MACRO `form`>`
  `SYMBOL-MACRO` handler
`#<MACRO `function`>`
  macro expander (defined by `DEFMACRO` and friends)
`#<`FFI:FOREIGN-POINTER` #x...>`
  foreign pointer (Platform Dependent: UNIX, Win32 platforms only.)
`#<`FFI:FOREIGN-ADDRESS` #x...>`
  foreign address (Platform Dependent: UNIX, Win32 platforms only.)
`#<`FFI:FOREIGN-VARIABLE` `name` #x...>`
  foreign variable (Platform Dependent: UNIX, Win32 platforms only.)
`#<`FFI:FOREIGN-FUNCTION` `name` #x...>`
  foreign function (Platform Dependent: UNIX, Win32 platforms only.)
`#<UNBOUND>`
  “value” of an unbound symbol, an unsupplied optional or keyword argument
`#<SPECIAL REFERENCE>`
  environment marker for variables declared `SPECIAL`
`#<DOT>`
  internal `READ` result for “.”
`#<END OF FILE>`
  internal `READ` result, when the `end-of-stream` is reached
`#<READ-LABEL ...>`
  intermediate `READ` result for `#n#`
`#<ADDRESS #x...>`
  machine address, should not occur
`#<SYSTEM-POINTER #x...>`
  should not occur

| These notes document CLISP version 2.45 | Last modified: 2008-05-14

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