- Reference manual
- The SWI-Prolog library
- library(aggregate): Aggregation operators on backtrackable predicates
- library(apply): Apply predicates on a list
- library(assoc): Association lists
- library(broadcast): Broadcast and receive event notifications
- library(charsio): I/O on Lists of Character Codes
- library(check): Consistency checking
- library(clpb): CLP(B): Constraint Logic Programming over Boolean Variables
- library(clpfd): CLP(FD): Constraint Logic Programming over Finite Domains
- library(clpqr): Constraint Logic Programming over Rationals and Reals
- library(csv): Process CSV (Comma-Separated Values) data
- library(debug): Print debug messages and test assertions
- library(error): Error generating support
- library(gensym): Generate unique identifiers
- library(iostream): Utilities to deal with streams
- library(lists): List Manipulation
- library(main): Provide entry point for scripts
- library(nb_set): Non-backtrackable set
- library(www_browser): Activating your Web-browser
- library(option): Option list processing
- library(optparse): command line parsing
- library(ordsets): Ordered set manipulation
- library(pairs): Operations on key-value lists
- library(persistency): Provide persistent dynamic predicates
- library(pio): Pure I/O
- library(predicate_options): Declare option-processing of predicates
- library(prolog_pack): A package manager for Prolog
- library(prolog_xref): Cross-reference data collection library
- library(quasi_quotations): Define Quasi Quotation syntax
- library(random): Random numbers
- library(readutil): Reading lines, streams and files
- library(record): Access named fields in a term
- library(registry): Manipulating the Windows registry
- library(simplex): Solve linear programming problems
- library(solution_sequences): Modify solution sequences
- library(tabling): Tabled execution (SLG)
- library(thread_pool): Resource bounded thread management
- library(ugraphs): Unweighted Graphs
- library(url): Analysing and constructing URL
- library(varnumbers): Utilities for numbered terms
- library(yall): Lambda expressions
- The SWI-Prolog library
- Reference manual
- See also
This library contains utilities that deal with streams, notably originating from non-built-in sources such as URLs, archives, windows, processes, etc.
The predicate open_any/5
acts as a broker between applications that can process data from
a stream and libraries that can create streams from diverse sources.
Without this predicate, processing data inevitally follows the pattern
below. As call_some_open_variation can be anything, this blocks
us from writing predicates such as
load_xml(From, DOM) that
can operate on arbitrary input sources.
setup_call_cleanup( call_some_open_variation(Spec, In), process(In), close(In)).
- open_any(+Specification, +Mode, -Stream, -Close, +Options)
- Establish a stream from Specification that should be closed
using Close, which can either be called or passed to
- Set stream to encoding Enc.
- A plain stream handle. Possisible post-processing options such as encoding are applied. Close does not close the stream, but resets other side-effects such as the encoding.
- Same as a plain Stream.
- If Specification is of the form =file://...=, the pointed to
file is opened using open/4.
library(uri)to be installed.
- Explicitly open the file Path. Path can be an Path(File) term as accepted by absolute_file_name/3.
- Open a Prolog string, atom, list of characters or codes as an input stream.
The typical usage scenario is given in the code below, where <process> processes the input.
setup_call_cleanup( open_any(Spec, read, In, Close, Options), <process>(In), Close).
Currently, the following libraries extend this predicate:
- Adds support for URLs using the
- Execute the Close closure returned by open_any/5. The closure can also be called directly. Using close_any/1 can be considered better style and enhances tractability of the source code.
- [semidet,multifile]open_hook(+Spec, +Mode, -Stream, -Close, +Options0, -Options)
- Open Spec in Mode, producing Stream.
Close is unified to a goal that must be called to undo the side-effects of the action, e.g., typically the term
Options0 are the options passed to open_any/5 Options are passed to the post processing filters that may be installed by open_any/5.