commit 2f1568ca38beb41f0eae3ae285e5f7db65a666a2
parent 1bc725972505daef11cd942680bf6c602c926f74
Author: Wolfgang Corcoran-Mathe <wcm@sigwinch.xyz>
Date: Tue, 6 Feb 2024 14:49:16 -0500
Formal syntax: Reflow paragraphs.
Diffstat:
1 file changed, 57 insertions(+), 53 deletions(-)
diff --git a/doc/r7rs-small/formal-syntax.texinfo b/doc/r7rs-small/formal-syntax.texinfo
@@ -1,18 +1,18 @@
@node Formal syntax
@section Formal syntax
-This section provides a formal syntax for Scheme written in an extended
-BNF.
+This section provides a formal syntax for Scheme written in an
+extended BNF.
All spaces in the grammar are for legibility. Case is not significant
-except in the definitions of @svar{letter}, @svar{character name} and @svar{mnemonic escape}; for example, @code{#x1A}
-and @code{#X1a} are equivalent, but @code{foo} and @code{Foo}
-and @code{#\space} and @code{#\Space} are distinct.
-@svar{empty} stands for the empty string.
-
-The following extensions to BNF are used to make the description more
-concise: @arbno{@svar{thing}} means zero or more occurrences of
-@svar{thing}; and @atleastone{@svar{thing}} means at least one
+except in the definitions of @svar{letter}, @svar{character name}
+and @svar{mnemonic escape}; for example, @code{#x1A} and @code{#X1a}
+are equivalent, but @code{foo} and @code{Foo} and @code{#\space} and
+@code{#\Space} are distinct. @svar{empty} stands for the empty string.
+
+The following extensions to BNF are used to make the description
+more concise: @arbno{@svar{thing}} means zero or more occurrences
+of @svar{thing}; and @atleastone{@svar{thing}} means at least one
@svar{thing}.
@menu
@@ -28,41 +28,39 @@ concise: @arbno{@svar{thing}} means zero or more occurrences of
@node Lexical structure
@subsection Lexical structure
-This section describes how individual tokens (identifiers,
-numbers, etc.) are formed from sequences of characters. The following
-sections describe how expressions and programs are formed from sequences
+This section describes how individual tokens (identifiers, numbers,
+etc.) are formed from sequences of characters. The following sections
+describe how expressions and programs are formed from sequences
of tokens.
-@svar{Intertoken space} can occur on either side of any token, but not
-within a token.
+@svar{Intertoken space} can occur on either side of any token, but
+not within a token.
-Identifiers that do not begin with a vertical line are
-terminated by a @svar{delimiter} or by the end of the input.
-So are dot, numbers, characters, and booleans.
-Identifiers that begin with a vertical line are terminated by another vertical line.
+Identifiers that do not begin with a vertical line are terminated by
+a @svar{delimiter} or by the end of the input. So are dot, numbers,
+characters, and booleans. Identifiers that begin with a vertical
+line are terminated by another vertical line.
-The following four characters from the ASCII repertoire
-are reserved for future extensions to the
-language: @code{[ ] @{ @}}
+The following four characters from the ASCII repertoire are reserved
+for future extensions to the language: @code{[ ] @{ @}}
-In addition to the identifier characters of the ASCII repertoire specified
-below, Scheme implementations may permit any additional repertoire of
-Unicode characters to be employed in identifiers,
+In addition to the identifier characters of the ASCII repertoire
+specified below, Scheme implementations may permit any additional
+repertoire of Unicode characters to be employed in identifiers,
provided that each such character has a Unicode general category of Lu,
Ll, Lt, Lm, Lo, Mn, Mc, Me, Nd, Nl, No, Pd, Pc, Po, Sc, Sm, Sk, So,
or Co, or is U+200C or U+200D (the zero-width non-joiner and joiner,
respectively, which are needed for correct spelling in Persian, Hindi,
-and other languages).
-However, it is an error for the first character to have a general category
-of Nd, Mc, or Me. It is also an error to use a non-Unicode character
-in symbols or identifiers.
+and other languages). However, it is an error for the first character
+to have a general category of Nd, Mc, or Me. It is also an error to
+use a non-Unicode character in symbols or identifiers.
All Scheme implementations must permit the escape sequence
-@code{\x}@svar{hexdigits}@code{;}
-to appear in Scheme identifiers that are enclosed in vertical lines. If the character
-with the given Unicode scalar value is supported by the implementation,
-identifiers containing such a sequence are equivalent to identifiers
-containing the corresponding character.
+@code{\x}@svar{hexdigits}@code{;} to appear in Scheme identifiers
+that are enclosed in vertical lines. If the character with the given
+Unicode scalar value is supported by the implementation, identifiers
+containing such a sequence are equivalent to identifiers containing
+the corresponding character.
@c TODO: Better alignment in output.
@format
@@ -89,8 +87,8 @@ containing the corresponding character.
@svar{directive} @expansion{} @code{#!fold-case} | @code{#!no-fold-case}
@end format
-Note that it is ungrammatical to follow a @svar{directive} with anything
-but a @svar{delimiter} or the end of file.
+Note that it is ungrammatical to follow a @svar{directive} with
+anything but a @svar{delimiter} or the end of file.
@format
@svar{atmosphere} @expansion{} @svar{whitespace} ∣ @svar{comment}
@@ -98,8 +96,8 @@ but a @svar{delimiter} or the end of file.
@svar{intertoken space} @expansion{} @arbno{@svar{atmosphere}}
@end format
-Note that @code{+i}, @code{-i} and @svar{infnan} below are exceptions to the
-@svar{peculiar identifier} rule; they are parsed as numbers, not
+Note that @code{+i}, @code{-i} and @svar{infnan} below are exceptions
+to the @svar{peculiar identifier} rule; they are parsed as numbers, not
identifiers.
@format
@@ -162,11 +160,13 @@ identifiers.
@svar{byte} @expansion{} @pseudoprod{any exact integer between 0 and 255}
@end format
-The following rules for @svar{num R}, @svar{complex R}, @svar{real R}, @svar{ureal R}, @svar{uinteger R}, and
-@svar{prefix R} are implicitly replicated for R = 2, 8, 10, and 16. There are no rules for @svar{decimal
-2}, @svar{decimal 8}, and @svar{decimal 16}, which means that numbers containing decimal points
-or exponents are always in decimal radix. Although not shown below, all alphabetic
-characters used in the grammar of numbers can appear in either upper or lower case.
+The following rules for @svar{num R}, @svar{complex R}, @svar{real R},
+@svar{ureal R}, @svar{uinteger R}, and @svar{prefix R} are implicitly
+replicated for R = 2, 8, 10, and 16. There are no rules for
+@svar{decimal 2}, @svar{decimal 8}, and @svar{decimal 16}, which means
+that numbers containing decimal points or exponents are always in
+decimal radix. Although not shown below, all alphabetic characters used
+in the grammar of numbers can appear in either upper or lower case.
@format
@svar{num @var{R}} @expansion{} @svar{prefix @var{R}}
@@ -220,8 +220,9 @@ characters used in the grammar of numbers can appear in either upper or lower ca
@node External representations formal
@subsection External representations
-@svar{Datum} is what the read procedure (@ref{Input}) successfully parses. Note that any
-string that parses as an @svar{expression} will also parse as a @svar{datum}.
+@svar{Datum} is what the read procedure (@ref{Input}) successfully
+parses. Note that any string that parses as an @svar{expression} will
+also parse as a @svar{datum}.
@format
@svar{datum} @expansion{} @svar{simple datum} ∣ @svar{compound datum}
@@ -244,18 +245,20 @@ string that parses as an @svar{expression} will also parse as a @svar{datum}.
@node Expressions formal
@subsection Expressions
-The definitions in this and the following subsections assume that all the syntax keywords
-defined in this report have been properly imported from their libraries, and that none of
-them have been redefined or shadowed.
+The definitions in this and the following subsections assume that all
+the syntax keywords defined in this report have been properly imported
+from their libraries, and that none of them have been redefined or
+shadowed.
[grammar]
@node Quasiquotations
@subsection Quasiquotations
-The following grammar for quasiquote expressions is not context-free. It is presented as
-a recipe for generating an infinite number of production rules. Imagine a copy of the
-following rules for @var{D} = 1, 2, 3, @dots{}, where @var{D} is the nesting depth.
+The following grammar for quasiquote expressions is not context-free.
+It is presented as a recipe for generating an infinite number of
+production rules. Imagine a copy of the following rules for @var{D} =
+1, 2, 3, @dots{}, where @var{D} is the nesting depth.
[grammar]
@@ -269,8 +272,9 @@ The interpretation as an @svar{unquotation} or
@node Transformers
@subsection Transformers
-Note: Though this grammar does not say so, a top-level @code{syntax-rules} pattern must be
-a list pattern, not a vector pattern or an identifier pattern.
+Note: Though this grammar does not say so, a top-level
+@code{syntax-rules} pattern must be a list pattern, not a vector
+pattern or an identifier pattern.
[grammar]
