clojure.pprint
Full namespace name: clojure.pprint
Overview
A Pretty Printer for Clojure clojure.pprint implements a flexible system for printing structured data in a pleasing, easy-to-understand format. Basic use of the pretty printer is simple, just call pprint instead of println. More advanced users can use the building blocks provided to create custom output formats. Out of the box, pprint supports a simple structured format for basic data and a specialized format for Clojure source code. More advanced formats, including formats that don't look like Clojure data at all like XML and JSON, can be rendered by creating custom dispatch functions. In addition to the pprint function, this module contains cl-format, a text formatting function which is fully compatible with the format function in Common Lisp. Because pretty printing directives are directly integrated with cl-format, it supports very concise custom dispatch. It also provides a more powerful alternative to Clojure's standard format function. See documentation for pprint and cl-format for more information or complete documentation on the the clojure web site on github.Added in Clojure version 1.2
Related documentation: A Common Lisp-compatible Format Function
A Pretty Printer for Clojure
Public Variables and Functions
*print-base*dynamic var
The base to use for printing integers and rationals.
Added in Clojure version 1.2
Source*print-miser-width*dynamic var
The column at which to enter miser style. Depending on the dispatch table, miser style add newlines in more places to try to keep lines short allowing for further levels of nesting.
Added in Clojure version 1.2
Source*print-pprint-dispatch*dynamic multimethod
No usage documentation available
The pretty print dispatch function. Use with-pprint-dispatch or set-pprint-dispatch to modify.
Added in Clojure version 1.2
Source*print-pretty*dynamic var
Bind to true if you want write to use pretty printing
Added in Clojure version 1.2
Source*print-radix*dynamic var
Print a radix specifier in front of integers and rationals. If *print-base* is 2, 8, or 16, then the radix specifier used is #b, #o, or #x, respectively. Otherwise the radix specifier is in the form #XXr where XX is the decimal value of *print-base*
Added in Clojure version 1.2
Source*print-right-margin*dynamic var
Pretty printing will try to avoid anything going beyond this column. Set it to nil to have pprint let the line be arbitrarily long. This will ignore all non-mandatory newlines.
Added in Clojure version 1.2
Source*print-suppress-namespaces*dynamic var
Don't print namespaces with symbols. This is particularly useful when pretty printing the results of macro expansions
Added in Clojure version 1.2
Sourcecl-formatfunction
Usage: (cl-format writer format-in & args)
An implementation of a Common Lisp compatible format function. cl-format formats its
arguments to an output stream or string based on the format control string given. It
supports sophisticated formatting of structured data.
Writer is an instance of java.io.Writer, true to output to *out* or nil to output
to a string, format-in is the format control string and the remaining arguments
are the data to be formatted.
The format control string is a string to be output with embedded 'format directives'
describing how to format the various arguments passed in.
If writer is nil, cl-format returns the formatted result string. Otherwise, cl-format
returns nil.
For example:
(let [results [46 38 22]]
(cl-format true "There ~[are~;is~:;are~]~:* ~d result~:p: ~{~d~^, ~}~%"
(count results) results))
Prints to *out*:
There are 3 results: 46, 38, 22
Detailed documentation on format control strings is available in the "Common Lisp the
Language, 2nd edition", Chapter 22 (available online at:
http://www.cs.cmu.edu/afs/cs.cmu.edu/project/ai-repository/ai/html/cltl/clm/node200.html#SECTION002633000000000000000)
and in the Common Lisp HyperSpec at
http://www.lispworks.com/documentation/HyperSpec/Body/22_c.htm Added in Clojure version 1.2
Sourcecode-dispatchmultimethod
Usage: (code-dispatch object)
The pretty print dispatch function for pretty printing Clojure code.
Added in Clojure version 1.2
Sourceformattermacro
Usage: (formatter format-in)
Makes a function which can directly run format-in. The function is fn [stream & args] ... and returns nil unless the stream is nil (meaning output to a string) in which case it returns the resulting string. format-in can be either a control string or a previously compiled format.
Added in Clojure version 1.2
Sourceformatter-outmacro
Usage: (formatter-out format-in)
Makes a function which can directly run format-in. The function is fn [& args] ... and returns nil. This version of the formatter macro is designed to be used with *out* set to an appropriate Writer. In particular, this is meant to be used as part of a pretty printer dispatch method. format-in can be either a control string or a previously compiled format.
Added in Clojure version 1.2
Sourcefresh-linefunction
Usage: (fresh-line)
Make a newline if *out* is not already at the beginning of the line. If *out* is not a pretty writer (which keeps track of columns), this function always outputs a newline.
Added in Clojure version 1.2
Sourceget-pretty-writerfunction
Usage: (get-pretty-writer writer)
Returns the java.io.Writer passed in wrapped in a pretty writer proxy, unless it's
already a pretty writer. Generally, it is unnecessary to call this function, since pprint,
write, and cl-format all call it if they need to. However if you want the state to be
preserved across calls, you will want to wrap them with this.
For example, when you want to generate column-aware output with multiple calls to cl-format,
do it like in this example:
(defn print-table [aseq column-width]
(binding [*out* (get-pretty-writer *out*)]
(doseq [row aseq]
(doseq [col row]
(cl-format true "~4D~7,vT" col column-width))
(prn))))
Now when you run:
user> (print-table (map #(vector % (* % %) (* % % %)) (range 1 11)) 8)
It prints a table of squares and cubes for the numbers from 1 to 10:
1 1 1
2 4 8
3 9 27
4 16 64
5 25 125
6 36 216
7 49 343
8 64 512
9 81 729
10 100 1000 Added in Clojure version 1.2
Sourceppmacro
Usage: (pp)
A convenience macro that pretty prints the last thing output. This is exactly equivalent to (pprint *1).
Added in Clojure version 1.2
Sourcepprintfunction
Usage: (pprint object)
(pprint object writer)
Pretty print object to the optional output writer. If the writer is not provided, print the object to the currently bound value of *out*.
Added in Clojure version 1.2
Sourcepprint-indentfunction
Usage: (pprint-indent relative-to n)
Create an indent at this point in the pretty printing stream. This defines how following lines are indented. relative-to can be either :block or :current depending whether the indent should be computed relative to the start of the logical block or the current column position. n is an offset. This function is intended for use when writing custom dispatch functions. Output is sent to *out* which must be a pretty printing writer.
Added in Clojure version 1.2
Sourcepprint-logical-blockmacro
Usage: (pprint-logical-block options* body)
Execute the body as a pretty printing logical block with output to *out* which must be a pretty printing writer. When used from pprint or cl-format, this can be assumed. This function is intended for use when writing custom dispatch functions. Before the body, the caller can optionally specify options: :prefix, :per-line-prefix, and :suffix.
Added in Clojure version 1.2
Sourcepprint-newlinefunction
Usage: (pprint-newline kind)
Print a conditional newline to a pretty printing stream. kind specifies if the newline is :linear, :miser, :fill, or :mandatory. This function is intended for use when writing custom dispatch functions. Output is sent to *out* which must be a pretty printing writer.
Added in Clojure version 1.2
Sourcepprint-tabfunction
Usage: (pprint-tab kind colnum colinc)
Tab at this point in the pretty printing stream. kind specifies whether the tab is :line, :section, :line-relative, or :section-relative. Colnum and colinc specify the target column and the increment to move the target forward if the output is already past the original target. This function is intended for use when writing custom dispatch functions. Output is sent to *out* which must be a pretty printing writer. THIS FUNCTION IS NOT YET IMPLEMENTED.
Added in Clojure version 1.2
Sourceprint-length-loopmacro
Usage: (print-length-loop bindings & body)
A version of loop that iterates at most *print-length* times. This is designed for use in pretty-printer dispatch functions.
Added in Clojure version 1.3
Sourceprint-tablefunction
Usage: (print-table ks rows)
(print-table rows)
Prints a collection of maps in a textual table. Prints table headings ks, and then a line of output for each row, corresponding to the keys in ks. If ks are not specified, use the keys of the first item in rows.
Added in Clojure version 1.3
Sourceset-pprint-dispatchfunction
Usage: (set-pprint-dispatch function)
Set the pretty print dispatch function to a function matching (fn [obj] ...) where obj is the object to pretty print. That function will be called with *out* set to a pretty printing writer to which it should do its printing. For example functions, see simple-dispatch and code-dispatch in clojure.pprint.dispatch.clj.
Added in Clojure version 1.2
Sourcesimple-dispatchmultimethod
Usage: (simple-dispatch object)
The pretty print dispatch function for simple data structure format.
Added in Clojure version 1.2
Sourcewith-pprint-dispatchmacro
Usage: (with-pprint-dispatch function & body)
Execute body with the pretty print dispatch function bound to function.
Added in Clojure version 1.2
Sourcewritefunction
Usage: (write object & kw-args)
Write an object subject to the current bindings of the printer control variables. Use the kw-args argument to override individual variables for this call (and any recursive calls). Returns the string result if :stream is nil or nil otherwise. The following keyword arguments can be passed with values: Keyword Meaning Default value :stream Writer for output or nil true (indicates *out*) :base Base to use for writing rationals Current value of *print-base* :circle* If true, mark circular structures Current value of *print-circle* :length Maximum elements to show in sublists Current value of *print-length* :level Maximum depth Current value of *print-level* :lines* Maximum lines of output Current value of *print-lines* :miser-width Width to enter miser mode Current value of *print-miser-width* :dispatch The pretty print dispatch function Current value of *print-pprint-dispatch* :pretty If true, do pretty printing Current value of *print-pretty* :radix If true, prepend a radix specifier Current value of *print-radix* :readably* If true, print readably Current value of *print-readably* :right-margin The column for the right margin Current value of *print-right-margin* :suppress-namespaces If true, no namespaces in symbols Current value of *print-suppress-namespaces* * = not yet supported
Added in Clojure version 1.2
Sourcewrite-outfunction
Usage: (write-out object)
Write an object to *out* subject to the current bindings of the printer control variables. Use the kw-args argument to override individual variables for this call (and any recursive calls). *out* must be a PrettyWriter if pretty printing is enabled. This is the responsibility of the caller. This method is primarily intended for use by pretty print dispatch functions that already know that the pretty printer will have set up their environment appropriately. Normal library clients should use the standard "write" interface.
Added in Clojure version 1.2
Source
© Rich Hickey
Licensed under the Eclipse Public License 1.0.
https://clojure.github.io/clojure/branch-clojure-1.8.0/clojure.pprint-api.html