Package org.projog.core.predicate.builtin.io

Class Writef

java.lang.Object

org.projog.core.predicate.AbstractSingleResultPredicate

org.projog.core.predicate.builtin.io.Writef

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory

public final class Writef
extends AbstractSingleResultPredicate

writef(X,Y) - writes formatted text to the output stream.

The first argument is an atom representing the text to be output. The text can contain special character sequences which specify formatting and substitution rules.

Supported special character sequences are:

Sequence	Action
\n	Output a 'new line' character (ASCII code 10).
\l	Same as \n.
\r	Output a 'carriage return' character (ASCII code 13).
\t	Output a tab character (ASCII code 9).
\\	Output the \ character.
\%	Output the % character.
\\uNNNN	Output the unicode character represented by the hex digits NNNN.
%t	Output the next term - in same format as write/1.
%w	Same as \t.
%q	Same as \t.
%p	Same as \t.
%d	Output the next term - in same format as write_canonical/1.
%f	Ignored (only included to support compatibility with other Prologs).
%s	Output the elements contained in the list represented by the next term.
%n	Output the character code of the next term.
%r	Write the next term N times, where N is the value of the second term.
%Nc	Write the next term centered in N columns.
%Nl	Write the next term left-aligned in N columns.
%Nr	Write the next term right-aligned in N columns.

writef(X) produces the same results as writef(X, []).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	Writef.Formatter

Constructor Summary

Constructors

Constructor	Description
Writef()

Method Summary

Modifier and Type	Method	Description
private java.lang.String	align(Writef.Formatter f, Term t)
private java.lang.String	concat(Writef.Formatter f, Term t)
protected boolean	evaluate(Term atom)
protected boolean	evaluate(Term atom, Term list)
private java.lang.StringBuilder	format(java.lang.String text, java.util.List<Term> args)
private java.lang.String	getWhitespace(int diff)
private boolean	isNumber(int c)
private int	parseNumber(Writef.Formatter f)
private void	parsePercentEscapeSequence(Writef.Formatter f)
private void	parseSlashEscapeSequence(Writef.Formatter f)
private int	parseUnicode(Writef.Formatter f)
private void	print(java.lang.StringBuilder sb)
private java.lang.String	repeat(java.lang.String text, long timesToRepeat)

Methods inherited from class org.projog.core.predicate.AbstractSingleResultPredicate

evaluate, evaluate, evaluate, evaluate, getArithmeticOperators, getFileHandles, getKnowledgeBase, getOperands, getPredicate, getPredicates, getProjogListeners, getSpyPoints, getTermFormatter, init, isRetryable, setKnowledgeBase

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.projog.core.predicate.PredicateFactory

isAlwaysCutOnBacktrack

Constructor Detail

Writef

public Writef()

Method Detail

evaluate

protected boolean evaluate(Term atom)

Overrides:

evaluate in class AbstractSingleResultPredicate

evaluate

protected boolean evaluate(Term atom,
                           Term list)

Overrides:

evaluate in class AbstractSingleResultPredicate

format

private java.lang.StringBuilder format(java.lang.String text,
                                       java.util.List<Term> args)

parsePercentEscapeSequence

private void parsePercentEscapeSequence(Writef.Formatter f)

repeat

private java.lang.String repeat(java.lang.String text,
                                long timesToRepeat)

concat

private java.lang.String concat(Writef.Formatter f,
                                Term t)

align

private java.lang.String align(Writef.Formatter f,
                               Term t)

getWhitespace

private java.lang.String getWhitespace(int diff)

parseNumber

private int parseNumber(Writef.Formatter f)

parseSlashEscapeSequence

private void parseSlashEscapeSequence(Writef.Formatter f)

parseUnicode

private int parseUnicode(Writef.Formatter f)

isNumber

private boolean isNumber(int c)

print

private void print(java.lang.StringBuilder sb)