Fix some bugs in the dynamic engraver and PostScript backend

[lilypond.git] / Documentation / user / scheme-tutorial.itely

diff --git a/Documentation/user/scheme-tutorial.itely b/Documentation/user/scheme-tutorial.itely
index bd4372ac0f7bcf419865d9fcfa4f853d74fcffb3..032fce0cf8b265644b620a37f3ed147a260557e6 100644 (file)
--- a/Documentation/user/scheme-tutorial.itely
+++ b/Documentation/user/scheme-tutorial.itely
@@ -3,7 +3,7 @@
 @node Scheme tutorial
 @appendix Scheme tutorial
 
-@cindex @code{#}
+@findex #
 @cindex Scheme
 @cindex GUILE
 @cindex Scheme, in-line code
@@ -14,8 +14,8 @@
 LilyPond uses the Scheme programming language, both as part of the
 input syntax, and as internal mechanism to glue modules of the program
 together.  This section is a very brief overview of entering data in
-Scheme.@footnote{If you want to know more about Scheme, see
-@uref{http://@/www@/.schemers@/.org}.}
+Scheme.  If you want to know more about Scheme, see
+@uref{http://@/www@/.schemers@/.org}.
 
 The most basic thing of a language is data: numbers, character
 strings, lists, etc.  Here is a list of data types that are relevant to
@@ -25,13 +25,13 @@ LilyPond input.
 @item Booleans
 Boolean values are True or False.  The Scheme for True is @code{#t}
 and False is @code{#f}.
-@cindex @code{##t}
-@cindex @code{##f}
+@findex ##t
+@findex ##f
 
 @item Numbers
 Numbers are entered in the standard fashion,
 @code{1} is the (integer) number one, while @code{-1.5} is a
-floating point number (a non-integer number). 
+floating point number (a non-integer number).
 
 @item Strings
 Strings are enclosed in double quotes,
@@ -64,7 +64,7 @@ In a music file, snippets of Scheme code are introduced with the hash
 mark @code{#}.  So, the previous examples translated in LilyPond are
 
 @example
-##t ##f 
+##t ##f
 #1 #-1.5
 #"this is a string"
 #"this
@@ -81,7 +81,7 @@ traditional @math{1+2}.
 
 @lisp
 #(+ 1 2)
-  @result{} #3 
+  @result{} #3
 @end lisp
 
 The arrow @result{} shows that the result of evaluating @code{(+ 1 2)}
@@ -90,24 +90,24 @@ be used for another calculation.
 
 @lisp
 #(+ 1 (* 3 4))
-  @result{} #(+ 1 12) 
+  @result{} #(+ 1 12)
   @result{} #13
 @end lisp
 
 These calculations are examples of evaluations; an expression like
 @code{(* 3 4)} is replaced by its value @code{12}.  A similar thing
-happens with variables.  After defining a variable  
+happens with variables.  After defining a variable
 
 @example
-twelve = #12 
+twelve = #12
 @end example
 
 @noindent
 variables can also be used in expressions, here
 
 @example
-twentyFour = #(* 2 twelve) 
-@end example 
+twentyFour = #(* 2 twelve)
+@end example
 
 @noindent
 the number 24 is stored in the variable @code{twentyFour}.
@@ -124,7 +124,7 @@ number or a string.  It is entered as
 #'twentyFour
 @end example
 
-@cindex @code{#'symbol}
+@findex #'symbol
 @cindex quoting in Scheme
 
 The quote mark @code{'} prevents the Scheme interpreter from substituting
@@ -141,15 +141,17 @@ example
 
 This instruction adjusts the appearance of stems.  The value @code{2.6}
 is put into the @code{thickness} variable of a @code{Stem}
-object.  This makes stems almost twice as thick as their normal size.
-To distinguish between variables defined in input files (like
+object.  @code{thickness} is measured relative to the thickness of
+staff lines, so these stem lines will be @code{2.6} times the
+width of staff lines.  This makes stems almost twice as thick as their
+normal size. To distinguish between variables defined in input files (like
 @code{twentyFour} in the example above) and variables of internal
 objects, we will call the latter ``properties'' and the former
 ``identifiers.''  So, the stem object has a @code{thickness} property,
 while @code{twentyFour} is an identifier.
 
 @cindex properties vs. identifiers
-@cindex identifiers vs. properties 
+@cindex identifiers vs. properties
 
 Two-dimensional offsets (X and Y coordinates) as well as object sizes
 (intervals with a left and right point) are entered as @code{pairs}.  A
@@ -158,8 +160,8 @@ and its two elements are called @code{car} and @code{cdr} respectively.}
 is entered as @code{(first . second)} and, like symbols, they must be quoted,
 
 @example
-\override TextScript #'extra-offset = #'(1 . 2)  
-@end example 
+\override TextScript #'extra-offset = #'(1 . 2)
+@end example
 
 This assigns the pair (1, 2) to the @code{extra-offset} property of the
 TextScript object.  These numbers are measured in staff-spaces, so