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Send bugs and suggestions to <texi2html-bug@nongnu.org> --> <head> <title>GNU LilyPond Notation Reference: 6.5.1 Context evaluation</title> <meta name="description" content="GNU LilyPond Notation Reference: 6.5.1 Context evaluation"> <meta name="keywords" content="GNU LilyPond Notation Reference: 6.5.1 Context evaluation"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="texi2html 1.82"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <link href="index.ja.html#index" rel="start" title="GNU LilyPond — Notation Reference"> <link href="LilyPond-command-index.ja.html#LilyPond-command-index" rel="index" title="F. LilyPond command index"> <link href="index_toc.ja.html#SEC_Contents" rel="contents" title="Table of Contents"> <link href="index_abt.ja.html#SEC_About" rel="help" title="About This Document"> <link href="Contexts-for-programmers.ja.html#Contexts-for-programmers" rel="up" title="6.5 Contexts for programmers"> <link href="LilyPond-index.ja.html#LilyPond-index" rel="next" title="G. LilyPond index"> <link href="Contexts-for-programmers.ja.html#Contexts-for-programmers" rel="previous" title="6.5 Contexts for programmers"> <link rel="stylesheet" type="text/css" title="Patrick McCarty's design" href="lilypond-mccarty.css"> <link rel="alternate stylesheet" type="text/css" href="lilypond.css" title="Andrew Hawryluk's design"> <link rel="alternate stylesheet" type="text/css" href="lilypond-blue.css" title="Kurt Kroon's blue design"> <!--[if lte IE 7]> <link href="lilypond-ie-fixes.css" rel="stylesheet" type="text/css"> <![endif]--> </head> <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> <div id="main"> <a name="Context-evaluation"></a> <table class="nav_table"> <tr><td valign="middle" align="left" colspan="1">[<a href="Interfaces-for-programmers.ja.html#Interfaces-for-programmers" title="Beginning of this chapter or previous chapter"> << Interfaces for programmers </a>]</td><td valign="middle" align="center" colspan="3">[<a href="index.ja.html#index" title="Cover (top) of document" rel="start">Top</a>][<a href="index_toc.ja.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="LilyPond-command-index.ja.html#LilyPond-command-index" title="Index" rel="index">Index</a>][<a href="index_abt.ja.html#SEC_About" title="About (help)" rel="help"> ? </a>]</td><td valign="middle" align="right" colspan="1">[<a href="Literature-list.ja.html#Literature-list" title="Next chapter"> Literature list >> </a>]</td></tr><tr><td valign="middle" align="left" colspan="2">[<a href="Contexts-for-programmers.ja.html#Contexts-for-programmers" title="Previous section in reading order" accesskey="p" rel="previous"> < Contexts for programmers </a>]</td><td valign="middle" align="center" colspan="1">[<a href="Contexts-for-programmers.ja.html#Contexts-for-programmers" title="Up section" accesskey="u" rel="up"> Up : Contexts for programmers </a>]</td><td valign="middle" align="right" colspan="2">[<a href="Running-a-function-on-all-layout-objects.ja.html#Running-a-function-on-all-layout-objects" title="Next section in reading order" accesskey="n" rel="next"> Running a function on all layout objects > </a>]</td></tr></table> <a name="Context-evaluation"></a> <h3 class="subsection">6.5.1 Context evaluation</h3> <a name="index-calling-code-during-interpreting"></a> <a name="index-_005capplyContext"></a> <a name="index-_005capplyContext-1"></a> <p>Contexts can be modified during interpretation with Scheme code. The syntax for this is </p><blockquote><pre class="example">\applyContext <var>function</var> </pre></blockquote> <p><var>function</var> should be a Scheme function taking a single argument, being the context to apply it to. The following code will print the current bar number on the standard output during the compile: </p> <blockquote><pre class="example">\applyContext #(lambda (x) (format #t "\nWe were called in barnumber ~a.\n" (ly:context-property x 'currentBarNumber))) </pre></blockquote> <hr size="6"> <table class="nav_table"> <tr><td valign="middle" align="left" colspan="1">[<a href="Interfaces-for-programmers.ja.html#Interfaces-for-programmers" title="Beginning of this chapter or previous chapter"> << Interfaces for programmers </a>]</td><td valign="middle" align="center" colspan="3">[<a href="index.ja.html#index" title="Cover (top) of document" rel="start">Top</a>][<a href="index_toc.ja.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="LilyPond-command-index.ja.html#LilyPond-command-index" title="Index" rel="index">Index</a>][<a href="index_abt.ja.html#SEC_About" title="About (help)" rel="help"> ? </a>]</td><td valign="middle" align="right" colspan="1">[<a href="Literature-list.ja.html#Literature-list" title="Next chapter"> Literature list >> </a>]</td></tr><tr><td valign="middle" align="left" colspan="2">[<a href="Contexts-for-programmers.ja.html#Contexts-for-programmers" title="Previous section in reading order" accesskey="p" rel="previous"> < Contexts for programmers </a>]</td><td valign="middle" align="center" colspan="1">[<a href="Contexts-for-programmers.ja.html#Contexts-for-programmers" title="Up section" accesskey="u" rel="up"> Up : Contexts for programmers </a>]</td><td valign="middle" align="right" colspan="2">[<a href="Running-a-function-on-all-layout-objects.ja.html#Running-a-function-on-all-layout-objects" title="Next section in reading order" accesskey="n" rel="next"> Running a function on all layout objects > </a>]</td></tr></table> <!-- footer_tag --> <div class="footer"> <p class="footer_version"> This page is for LilyPond-2.12.3 (stable-branch). </p> <p class="footer_report"> Your <a href="http://lilypond.org/web/devel/participating/documentation-adding">suggestions for the documentation</a> are welcome, please report errors to our <a href="http://post.gmane.org/post.php?group=gmane.comp.gnu.lilypond.bugs">bug list</a>. </p> </div> <p id="languages"> Other languages: <a href="Context-evaluation.es.html">espaƱol</a>. <br> </p> <!-- FOOTER --> <!-- end div#main here --> </div> <div id="tocframe"> <p class="toc_uplink"><a href="../index.ja.html" title="Documentation Index"><< Back to Documentation Index</a></p> <h4 class="toc_header"> <a href="index.ja.html#index" title="Start of the manual">Notation Reference</a></h4> <div class="contents"> <ul class="toc"> <li><a name="toc-Musical-notation-1" href="Musical-notation.ja.html#Musical-notation">1. Musical notation</a> <ul class="toc"> <li><a name="toc-Pitches-1" href="Pitches.ja.html#Pitches">1.1 Pitches</a> </li> <li><a name="toc-Rhythms-1" href="Rhythms.ja.html#Rhythms">1.2 Rhythms</a> </li> <li><a name="toc-Expressive-marks-1" href="Expressive-marks.ja.html#Expressive-marks">1.3 Expressive marks</a> </li> <li><a name="toc-Repeats-1" href="Repeats.ja.html#Repeats">1.4 Repeats</a> </li> <li><a name="toc-Simultaneous-notes-1" href="Simultaneous-notes.ja.html#Simultaneous-notes">1.5 Simultaneous notes</a> </li> <li><a name="toc-Staff-notation-1" href="Staff-notation.ja.html#Staff-notation">1.6 Staff notation</a> </li> <li><a name="toc-Editorial-annotations-1" href="Editorial-annotations.ja.html#Editorial-annotations">1.7 Editorial annotations</a> </li> <li><a name="toc-Text-1" href="Text.ja.html#Text">1.8 Text</a> </li> </ul> </li> <li><a name="toc-Specialist-notation-1" href="Specialist-notation.ja.html#Specialist-notation">2. Specialist notation</a> <ul class="toc"> <li><a name="toc-Vocal-music-1" href="Vocal-music.ja.html#Vocal-music">2.1 Vocal music</a> </li> <li><a name="toc-Keyboard-and-other-multi_002dstaff-instruments-1" href="Keyboard-and-other-multi_002dstaff-instruments.ja.html#Keyboard-and-other-multi_002dstaff-instruments">2.2 Keyboard and other multi-staff instruments</a> </li> <li><a name="toc-Unfretted-string-instruments-1" href="Unfretted-string-instruments.ja.html#Unfretted-string-instruments">2.3 Unfretted string instruments</a> </li> <li><a name="toc-Fretted-string-instruments-1" href="Fretted-string-instruments.ja.html#Fretted-string-instruments">2.4 Fretted string instruments</a> </li> <li><a name="toc-Percussion-1" href="Percussion.ja.html#Percussion">2.5 Percussion</a> </li> <li><a name="toc-Wind-instruments-1" href="Wind-instruments.ja.html#Wind-instruments">2.6 Wind instruments</a> </li> <li><a name="toc-Chord-notation-1" href="Chord-notation.ja.html#Chord-notation">2.7 Chord notation</a> </li> <li><a name="toc-Ancient-notation-1" href="Ancient-notation.ja.html#Ancient-notation">2.8 Ancient notation</a> </li> <li><a name="toc-World-music-1" href="World-music.ja.html#World-music">2.9 World music</a> </li> </ul> </li> <li><a name="toc-General-input-and-output-1" href="General-input-and-output.ja.html#General-input-and-output">3. General input and output</a> <ul class="toc"> <li><a name="toc-Input-structure-1" href="Input-structure.ja.html#Input-structure">3.1 Input structure</a> </li> <li><a name="toc-Titles-and-headers-1" href="Titles-and-headers.ja.html#Titles-and-headers">3.2 Titles and headers</a> </li> <li><a name="toc-Working-with-input-files-1" href="Working-with-input-files.ja.html#Working-with-input-files">3.3 Working with input files</a> </li> <li><a name="toc-Controlling-output-1" href="Controlling-output.ja.html#Controlling-output">3.4 Controlling output</a> </li> <li><a name="toc-MIDI-output-1" href="MIDI-output.ja.html#MIDI-output">3.5 MIDI output</a> </li> </ul> </li> <li><a name="toc-Spacing-issues-1" href="Spacing-issues.ja.html#Spacing-issues">4. Spacing issues</a> <ul class="toc"> <li><a name="toc-Paper-and-pages-1" href="Paper-and-pages.ja.html#Paper-and-pages">4.1 Paper and pages</a> </li> <li><a name="toc-Music-layout-1" href="Music-layout.ja.html#Music-layout">4.2 Music layout</a> </li> <li><a name="toc-Breaks-1" href="Breaks.ja.html#Breaks">4.3 Breaks</a> </li> <li><a name="toc-Vertical-spacing-1" href="Vertical-spacing.ja.html#Vertical-spacing">4.4 Vertical spacing</a> </li> <li><a name="toc-Horizontal-spacing-1" href="Horizontal-spacing.ja.html#Horizontal-spacing">4.5 Horizontal spacing</a> </li> <li><a name="toc-Fitting-music-onto-fewer-pages-1" href="Fitting-music-onto-fewer-pages.ja.html#Fitting-music-onto-fewer-pages">4.6 Fitting music onto fewer pages</a> </li> </ul> </li> <li><a name="toc-Changing-defaults-1" href="Changing-defaults.ja.html#Changing-defaults">5. Changing defaults</a> <ul class="toc"> <li><a name="toc-Interpretation-contexts-1" href="Interpretation-contexts.ja.html#Interpretation-contexts">5.1 Interpretation contexts</a> </li> <li><a name="toc-Explaining-the-Internals-Reference-1" href="Explaining-the-Internals-Reference.ja.html#Explaining-the-Internals-Reference">5.2 Explaining the Internals Reference</a> </li> <li><a name="toc-Modifying-properties-1" href="Modifying-properties.ja.html#Modifying-properties">5.3 Modifying properties</a> </li> <li><a name="toc-Useful-concepts-and-properties-1" href="Useful-concepts-and-properties.ja.html#Useful-concepts-and-properties">5.4 Useful concepts and properties</a> </li> <li><a name="toc-Advanced-tweaks-1" href="Advanced-tweaks.ja.html#Advanced-tweaks">5.5 Advanced tweaks</a> </li> </ul> </li> <li class="toc_current"><a name="toc-Interfaces-for-programmers-1" href="Interfaces-for-programmers.ja.html#Interfaces-for-programmers">6. Interfaces for programmers</a> <ul class="toc"> <li><a name="toc-Music-functions-1" href="Music-functions.ja.html#Music-functions">6.1 Music functions</a> </li> <li><a name="toc-Programmer-interfaces-1" href="Programmer-interfaces.ja.html#Programmer-interfaces">6.2 Programmer interfaces</a> </li> <li><a name="toc-Building-complicated-functions-1" href="Building-complicated-functions.ja.html#Building-complicated-functions">6.3 Building complicated functions</a> </li> <li><a name="toc-Markup-programmer-interface-1" href="Markup-programmer-interface.ja.html#Markup-programmer-interface">6.4 Markup programmer interface</a> </li> <li class="toc_current"><a name="toc-Contexts-for-programmers-1" href="Contexts-for-programmers.ja.html#Contexts-for-programmers">6.5 Contexts for programmers</a> <ul class="toc"> <li class="toc_current"><a name="toc-Context-evaluation-1" href="Context-evaluation.ja.html#Context-evaluation">6.5.1 Context evaluation</a> </li> <li><a name="toc-Running-a-function-on-all-layout-objects-1" href="Running-a-function-on-all-layout-objects.ja.html#Running-a-function-on-all-layout-objects">6.5.2 Running a function on all layout objects</a> </li> </ul> </li> <li><a name="toc-Scheme-procedures-as-properties-1" href="Scheme-procedures-as-properties.ja.html#Scheme-procedures-as-properties">6.6 Scheme procedures as properties</a> </li> <li><a name="toc-Using-Scheme-code-instead-of-_005ctweak-1" href="Using-Scheme-code-instead-of-_005ctweak.ja.html#Using-Scheme-code-instead-of-_005ctweak">6.7 Using Scheme code instead of <code>\tweak</code></a> </li> <li><a name="toc-Difficult-tweaks-1" href="Difficult-tweaks.ja.html#Difficult-tweaks">6.8 Difficult tweaks</a> </li> </ul> </li> <li><a name="toc-Literature-list-1" href="Literature-list.ja.html#Literature-list">A. Literature list</a> </li> <li><a name="toc-Notation-manual-tables-1" href="Notation-manual-tables.ja.html#Notation-manual-tables">B. Notation manual tables</a> <ul class="toc"> <li><a name="toc-Chord-name-chart-1" href="Chord-name-chart.ja.html#Chord-name-chart">B.1 Chord name chart</a> </li> <li><a name="toc-Common-chord-modifiers-1" href="Common-chord-modifiers.ja.html#Common-chord-modifiers">B.2 Common chord modifiers</a> </li> <li><a name="toc-Predefined-fretboard-diagrams-1" href="Predefined-fretboard-diagrams.ja.html#Predefined-fretboard-diagrams">B.3 Predefined fretboard diagrams</a> </li> <li><a name="toc-MIDI-instruments-1" href="MIDI-instruments.ja.html#MIDI-instruments">B.4 MIDI instruments</a> </li> <li><a name="toc-List-of-colors-1" href="List-of-colors.ja.html#List-of-colors">B.5 List of colors</a> </li> <li><a name="toc-The-Feta-font-1" href="The-Feta-font.ja.html#The-Feta-font">B.6 The Feta font</a> </li> <li><a name="toc-Note-head-styles-1" href="Note-head-styles.ja.html#Note-head-styles">B.7 Note head styles</a> </li> <li><a name="toc-Text-markup-commands-1" href="Text-markup-commands.ja.html#Text-markup-commands">B.8 Text markup commands</a> </li> <li><a name="toc-Text-markup-list-commands-1" href="Text-markup-list-commands.ja.html#Text-markup-list-commands">B.9 Text markup list commands</a> </li> <li><a name="toc-List-of-articulations-1" href="List-of-articulations.ja.html#List-of-articulations">B.10 List of articulations</a> </li> <li><a name="toc-Percussion-notes-1" href="Percussion-notes.ja.html#Percussion-notes">B.11 Percussion notes</a> </li> <li><a name="toc-All-context-properties-1" href="All-context-properties.ja.html#All-context-properties">B.12 All context properties</a> </li> <li><a name="toc-Layout-properties-1" href="Layout-properties.ja.html#Layout-properties">B.13 Layout properties</a> </li> <li><a name="toc-Identifiers-1" href="Identifiers.ja.html#Identifiers">B.14 Identifiers</a> </li> <li><a name="toc-Scheme-functions-1" href="Scheme-functions.ja.html#Scheme-functions">B.15 Scheme functions</a> </li> </ul> </li> <li><a name="toc-Cheat-sheet-1" href="Cheat-sheet.ja.html#Cheat-sheet">C. Cheat sheet</a> </li> <li><a name="toc-LilyPond-grammar-1" href="LilyPond-grammar.ja.html#LilyPond-grammar">D. LilyPond grammar</a> </li> <li><a name="toc-GNU-Free-Documentation-License-1" href="GNU-Free-Documentation-License.ja.html#GNU-Free-Documentation-License">E. GNU Free Documentation License</a> </li> <li><a name="toc-LilyPond-command-index-1" href="LilyPond-command-index.ja.html#LilyPond-command-index">F. LilyPond command index</a> </li> <li><a name="toc-LilyPond-index-1" href="LilyPond-index.ja.html#LilyPond-index">G. LilyPond index</a> </li> </ul> </div> </div> </body> </html>