Definition of the Breccian language - Breccia in practice is a production of texts, each comprising one or more documents. - Here the documents are defined in formal terms as document fracta.   │   │   ├──────┐   ╵ │ \ [graphical syntax notation], q.v. at end notes   document ▲   fractum │   ╷ │   ├──────┘   │   │   ▼ diagram, The form of a Breccian text. document fractum / A Breccian document in formal terms. - It comprises a head formed as a descriptor and/or a body formed as a sequence of body fracta.   │   │   ├──────┐ ┐   ╵ │ │   descriptor │ │ head   ╷ ▼ │   ┌─────┤ │ ┘   │ ├──────┘   │ │ ┐   │ ├─────┐ │   ▼ ╵ │ │   │ body ▲ │ body   │ fractum │ │   │ ╷ │ │   │ ├─────┘ │   └─────┤ ┘   │   │   ▼ - Either the descriptor or the body may be omitted, but not both. document title - The document title, if any, is determined by the first fractal head in linear order that yields a non-empty result after collapsing the whitespace of the relevant part of its content according to head type: • document head or point head - The relevant part is the whole head exclusive of commentary and indentation blinds. • divider - The relevant part is its first label. ━━━━━━━━━━━━━ Alarm point ───────────── / A specialized material point. - A point with a bullet comprising ‘!!’, or ending with ‘!!’. - It forms urgent matter for the attention of authors. / E.g. indicating an error in the document. ━━━━━━━━━━━━━ Aside point ───────────── / A specialized material point. - A point with a bullet comprising ‘/’. - It forms matter of less prominence than its place would otherwise suggest. / E.g. matter to which the reader should give less attention on a first reading. - Its descriptor, if present, is largely free form. : see `most descriptors are largely free form.$` @ `^^ Descriptor$` ━━━━━━━━━━━━━━━━━━━━━━━ Associative reference ─────────────────────── / A command point. - It indicates an object (the referent) and associates with it one or more preceding character sequences (the referrer, or referrers). - Its descriptor has this form:   referrer referent   ─── gap ──┬── clause ── gap ──┬── clause ────▶   │ │   └───────────────────┘ diagram, The form of the descriptor in an associative reference. - The referrer clause indicates the referrer or referrers. - The referent clause indicates the referent. - A single referrer may be associated with multiple referents. / via multiple, sibling references that indicate the same referrer - Multiple referrers may be overlapped or nested in any manner. / via multiple, sibling references / via a single reference that indicates multiple referrers at once referrer clause - The referrer clause indicates the referrer, or referrers, by a pattern of text occuring in the head of the reference’s parent.   ───╴‘re’╶── gap ──╴‘`’╶── pattern ──╴‘`’╶────▶ - Failing a parental head, the reference is misplaced and the document malformed. / This occurs only when the parent is a headless document fractum. - The referrer clause is optional. - If omitted, then the head of the reference’s parent is taken in effect as the referrer. effect - The effect is located in the simulacrum. if( the pattern contains one or more subexpression grouping constructs ‘(…)’ ) : re `subexpression grouping constructs` see https://perldoc.perl.org/perlreref.html#SYNTAX for( each match of the pattern within the head of the reference’s parent ) if( at least one subexpression captures a text sequence ) + Set as a referrer the union of all captured text sequences. else for( each match of the pattern within the head of the reference’s parent ) + Set as a referrer the whole of the matching text. referent clause - The referent clause indicates the referent.   URI   ┌─╴‘join’╶─┐ ┌── reference ──┐   ───┤ ├── gap ─┬─╴‘privately’╶─ gap ─┬──┤ ├────▶   └──╴‘see’╶─┘ │ │ │ fractum │   └─────────────────────┘ └── indicator ──┘   └───────────┘   referential   command : re `‘(join)’` see `^^ Jointer$` : re `‘(see)’` see `^^ Pointer$` : re `‘(privately)’` see `\`privately\` is given` @ `^^effect$` : re `(URI)$.*(reference)` see https://tools.ietf.org/html/rfc3986#section-4.1 - The referential command determines the type and overall function of the associative reference. : re `type` see `^^◇ associative reference$` @ `^^typology$` @ `^^ Fractum$` - A non-private reference to a private referent of the same author, or authors, is malformed. effect - The effect is located in the simulacrum. if( a URI reference is given ) + Take the referent of the URI reference as the indicated referent. else - A fractum indicator is given. if( its principal pattern is omitted ) if( the reference has a referrer clause ) + Set `p` to the pattern given in the referrer clause. + Set `p` to broadened to division titling( `p` ). : see `^^broadened to division titling\( pattern \)$` + Anchor `p` by appending ‘$$’. else + Set `p` to generalized pattern( head of the reference’s parent ). : see `^^generalized pattern\( fractal head \)$` + Set the principal pattern to `p`. if( the principal pattern contains a subexpression grouping construct ‘(…)’ ) : re `subexpression grouping construct` see https://perldoc.perl.org/perlreref.html#SYNTAX + Take as the indicated referent the union of the text sequences captured by all such grouping constructs of the pattern. else + Take as the indicated referent the whole of the indicated fractum. if( `privately` is given ) + Append as a child of the associative reference a privatizer. ━━━━━━━━ Bullet ──────── / Part of a point head. - Its internal form is determined in part by external boundaries.   perfect ┊ start end ┊ descriptor,   indentation ┊╶─── sequence ─┬─┬─ interior ─┬─ character ─┬───▶ ┊ head successor,   ┊ │ │ │ │ ┊ or end of document   │ └────────────┘ │ ┊   └────────────────────────────┘   i ii iii : re `head successor` see `^^\| the head successor$` @ `^^ Fractum$` diagram, The form of a bullet. - While the precise internal form varies according to the point type, every bullet is formally conditioned by basic contraints operating in several regions, here numbered i, ii, iii. i. start sequence, one of: | a character that is neither whitespace nor backslash (5C) nor divider mark : see `^^character identification$` @ `^^ Notes$` | one or more backslashes immediately followed by a character that is neither whitespace nor backslash \ Whitespace would make it a sequence of a comment block, not a bullet. ii. interior - Coming after the start character and before the end character. - Here the bullet may contain spacing characters, and nowhere else. - One or more plain spaces (20) may follow an alphanumeric character. : see `^^character identification$` @ `^^ Notes$` - Following any other character (C), they would expel both C and themselves from the interior. / So making C either the end character if it meets the constraints of one, or part of the end boundary. - One or more no-break spaces (A0) may follow any non-alphanumeric character other than a plain space, and other than a backslash occuring in a backslash sequence at the start of the bullet. \ The backslash case is excluded because it would \ complicate Breccia Mode for Emacs, and anyway appears to be useless. : re `Breccia Mode for Emacs` see http://reluk.ca/project/Breccia/Emacs/ - Here the excluded sequences are not expulsive, rather they are simply forbidden. - No other whitespace is allowed. / Namely no newline; one could never be part of a bullet, only of its end boundary. iii. end character, a character that is none of: | whitespace | a backslash subsequent to a plain space of the interior / Rather those characters would comprise the initial part of an end boundary in the form of inline commentary, so forming part of the descriptor. ━━━━━━━━━━━━━━━ Command point ─────────────── / A formal point. - A point with a bullet comprising ‘:’. - The form of its descriptor, if any, varies with the type of command point. : re `type of command point` see `^^typology$` @ `^^ Fractum$` / Only in the case of a *null command* may the descriptor be omitted. - Processors interpret command points and execute their commands in linear order. null command - A command point that does nothing. \ The null command is an artifact of formal consistency; \ it occurs only because a descriptor is defined as optional in the head of a point. - Its descriptor has this form:   ───┬─ gap ─┬───▶   │ │   └───────┘ ━━━━━━━━━━━━ Commentary ──────────── / Part of a descriptor. - Commentary is matter for the attention of authors, publishers or other atypical readers. - Formally it appears as either inline commentary or block commentary. inline commentary - Commentary subsequent to non-commentary, non-whitespace on the same line. \ [‘commentary’]   inline commentary   ┌─────────────────────────────────────────┐     ┌───╴◀────────┐   ┌─╴◀────┐ ┌─╴◀────┐ │ │   inline non- │ │ ┊ │ │ │ inline │ ┊ end of   -whitespace ╶─┴─╴‘ ’╶─┘ ┊╶──┴─╴‘\’╶─┴─┬─╴‘ ’╶─┬─┴─ character ─┴─┬─┬───▶ ┊ line   ┊ │ │ │ │ ┊   │ └─────────────────┘ │   └───────────────────────────┘ diagram, The form of inline commentary. block commentary - Commentary comprising whole lines. \ [‘commentary’] - Each line has this form:   ┌───╴◀────────┐   ┌─╴◀────┐ ┌─╴◀────┐ │ │   start ┊ │ │ │ │ │ inline │ ┊ end of   of ┊╶──┬─┴─╴‘ ’╶─┴─┬─┴─╴‘\’╶─┴─┬─╴‘ ’╶─┬─┴─ character ─┴─┬─┬───▶ ┊ line   line ┊ │ │ │ │ │ │ ┊   └───────────┘ │ └─────────────────┘ │   └───────────────────────────┘ diagram, The form of a line of block commentary. ━━━━━━━━━━━━ Descriptor ──────────── / Part of a document head or point head. - Elaborative, explanatory text in the head of a document or point. - It starts with a gap.   · · · ·   · · ┊ head successor,   ─── gap ─── · ? · ────▶ ┊ or end of document   · · ┊   · · · · : re `head successor` see `^^\| the head successor$` @ `^^ Fractum$` diagram, The abstract form of a descriptor. - What follows the gap (abstracted from the diagram) depends on the type of fractum in which the descriptor appears. - Here most descriptors are largely free form, constrained only by the end boundary of their head (as shown). - The descriptor of a formal point, however, is further constrained. : re `formal point` see `^^◇ formal point$` @ `^^typology$` @ `^^ Fractum$` gap - A type of separator used in a descriptor.   ┌────────────────────────╴◀──────────────────────────────────┐   │ │   │ ┌───────────────────────────╴‘ ’╶────────────────────────┐ │   │ │ │ │   ───┴─┤ block ├─┴───▶   │ ┌─── commentary ──┐ │   │ inline │ │ │   └─┬─╴‘ ’╶── commentary ─┬─ newline ──┤ indentation ├─┘   │ │ ├─── blind ───┤   └─────────────────────┘ │ │   └─────────────────┘ ━━━━━━━━━━ Division ────────── / A body fractum. - A body fractum forming a part of the document markedly separate from other parts. : re `markedly separate` see `^^divider$` - Its head is called a divider. ───────── divider ┈┈┈┈┈┈┈┈┈ - The head of a division. - It comprises one or more divider segments. - Therefore no two dividers can be made contiguous; rather they become two segments of one divider.   │   │   ├─────┐   ╵ │   divider ▲   segment │   ╷ │   ├─────┘   │   │   ▼ diagram, The form of a divider. divider segment / Part of a divider. - It starts with a perfectly indented divider mark.   perfect divider   indentation ─── mark   ╷   │   ┌─────┤   │ ├───────┐   │ ╵ │   │ character ▲   │ ╷ │   │ ├───────┘   └─────┤   │   │   ▼   ╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴   divider segment, point,   or end of document diagram, The form of a divider segment. - Any characters subsequent to the divider mark are largely free form, constrained only by the end boundary of the segment, as shown. divider mark - A character in the Unicode range 2500-259F. : re `2500-259F` see `^^character identification$` @ `^^ Notes$` - One of a drawing character or inversion mark. drawing character - Unicode 2500-2587, 2589-258F, 2591-259F. inversion mark - Unicode 2588 (full block), 2590 (right half block). ──────────────── division label ┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈ / Part of a divider segment. - A sequence in a divider of non divider-mark characters.   │   │   ╵   non   divider-mark,   non-whitespace   ╷   ┌─────────┤   │ ┌───────┤   │ │ ├────────┐   │ │ ╵ │   │ │ non ▲   │ │ divider-mark │   │ │ ╷ │   │ │ ├────────┘   │ └───────┤   │ ╵   │ non   │ divider-mark,   │ non-whitespace   │ ╷   └─────────┤   │   │   ▼ diagram, The form of a division label. inverse labeling / A deprecated part of a division label. - It occurs at the start of a division label bounded by an inversion marker.   inversion ┊ non non non   marker ┊╶───╴ divider-mark, ─┬─┬─ divider-mark, ─┬── divider-mark, ─┬───▶   ┊ non-whitespace │ │ non-newline │ non-whitespace │   │ │ │ │   │ └──────────────────┘ │   └───────────────────────────────────────┘ diagram, The form of inverse labeling. - Presenters show inverse labeling, together with any space characters that immediately precede or follow it, in reverse video. \ Not ‘inverse video’. https://www.lexico.com/en/definition/reverse_video - Exception: inline commentary is excluded and presented as is. - Inverse labeling is deprecated, liable to be removed from the language. \ It concerns presentation alone, making it improper to the language. \ It has turned out to be largely useless thus far. 2019-9 inversion marker   ┌─╴◀────┐   inversion │ │   ─── mark ──┬─┴─╴‘ ’╶─┴─┬───▶   │ │   └───────────┘ - Where a full block character (2588) succeeds an inversion mark on the same line, with at most non divider-mark characters in between, that full block is disabled as an inversion mark. : see `^^character identification$` @ `^^ Notes$` / The full block pairs with the preceding inversion mark and by itself does not start a new sequence of inverse labeling. division titling / A type of division labeling. - Division titling is division labeling that (discounting spaces, 20) leads the line on which it occurs. : see `^^character identification$` @ `^^ Notes$` -   ┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄╮   This is division titling, ┊ This is not   and this too ┊   ┄┄┄┄┄┄┄┄┄┄┄┄┄ This is not ┄╯ example: An example of division titling. The drawing sequences here (dashed lines) are perfectly indented. - Presenters may give greater prominence to division titling, e.g. showing it in bold face. ─────────────────── apparent division ┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈ - A group of siblings led by a bodiless division (bare divider). - It comprises the bodiless division and its subsequent siblings (in linear order) prior to the next sibling (if any) that is itself a division. / It is a flat form of partition, as opposed to the hierarchical form of true division. / It may be transformed to a true division by indenting the siblings to instead make them children of the divider. ━━━━━━━━━ Fractum ───────── - The basic formal unit of Breccian composition, hierarchy and order. typology • document fractum ◇ body fractum • division ◇ point ◇ formal point ◇ command point ◇ associative reference • jointer • pointer • null command • privatizer ◇ material point ◇ specialized material point • alarm point • aside point • task point • generic point abstract form - A fractum divides formally into two parts: a head and a body.   │   │   ╵   · · · · ┐   · · │   · ? · │ head   · · │   · · · · ┘   ╷   │   ┌─────┤ ┐   │ ├─────┐ │   │ ╵ │ │   │ body ▲ │ body   │ fractum │ │   │ ╷ │ │   │ ├─────┘ │   └─────┤ ┘   │   │   ▼ head - The part of a fractum exclusive of its children. - Its internal form (abstracted from the diagram) varies according to the fractum type. - Its end boundary (not fully shown) always comprises one of: | the head successor - The head successor (S) is the fractum succeeding the head in linear order. - In terms relative to the head’s own fractum F, S is the first applicable of: | the first child of F / in its body, that is | the next sibling of F | the next sibling of the nearest ancestor of F | the end of the document body - The part of a fractum comprising its children alone; a sequence of sibling body fracta. - A body is always optional: regardless of the fractum type, it may be omitted. fractal relatives • parent - The parent of a fractum is the first applicable of: | its nearest (in linear order) fractal precedecessor of less indentation | the document fractum • child - A fractum that has a parent. - All body fracta are children. - No document fractum is a child. ━━━━━━━━━━━━━━━━━━━━ Fractum indication ──────────────────── fractum indicator( default principal pattern ) - An indicator of a fractum, here referred to as ‘the principal fractum’.   ┌   1 │ ────▶   └     ┌ principal   2 │ ───╴ pattern ─────▶   └     ┌ ┌────╴◀─── gap ───┐   │ │ │   │ principal │ ancestor │   3 │ ───┬─╴ pattern ── gap ─┬─┴─ qualification ─┴───▶   │ │ │   └ └───────────────────┘     ┌ ┌────╴◀─── gap ───┐   │ │ │   │ principal │ ancestor │ document   4 │ ───┬─╴ pattern ── gap ─┬──┬─┴─ qualification ─┴─ gap ─┬── qualification ────▶   │ │ │ │ │   └ └───────────────────┘ └───────────────────────────┘ diagram, The four forms of a fractum indicator. - Where a formal definition refers to a fractum indicator, the reference must be qualified by the specification of a default value for the principal pattern, which also serves as the implied value of the whole fractum indicator if all its components are omitted. principal pattern - An indicator of the principal fractum by the pattern of its text.   ───╴‘`’╶── pattern ──╴‘`’╶───▶ - The indication it gives is the return value of this procedure: if( the pattern contains one or more subexpression grouping constructs ‘(…)’ ) : re `subexpression grouping constructs` see https://perldoc.perl.org/perlreref.html#SYNTAX for( each match of the pattern ) if( at least one subexpression captures a text sequence, and all captured text sequences lie within the same fractal head ) + Set as indicated the fractal head’s fractum. else for( each match of the pattern ) + Set as indicated the fractum whose head contains the first matched character in linear order. if( exactly one fractum is indicated ) return( the indicated fractum ) if( the referent document is Breccian ) throw( error, the indication is ambiguous ) generalized pattern( fractal head ) / Returns a generalized pattern of the given `fractal head`, which is commonly used to specify the default value for a principal pattern. + Set `p` to the text of the given `fractal head`. + Trim `p` of commentary. + Trim `p` of leading whitespace on its first line. + Trim `p` of trailing whitespace. + Set `p` to literalized pattern( `p` ). : see `^^literalized pattern\( string \)$` + Collapse all remaining whitespace of `p` to ‘\s+’. / Neutralizing differences in indentation and line wrapping. if( `fractal head` is a divider ) + Anchor `p` by prepending ‘^^’. for( each repetitive sequence (S) of a drawing character (C) in `p` ) + Collapse S to a single C followed by ‘+’. / Neutralizing differences in horizontal length, e.g. owing to indentation. else if( `p` ends with literalized pattern(‘+’) or literalized pattern(‘!!’) ) / Then `fractal head` may comprise a task bullet or alarm bullet. if( `p` does not comprise literalized pattern(‘+’) or literalized pattern(‘!!’) ) / Viz the (potential) bullet here is not ‘+’ or ‘!!’ alone. + Append ‘?’. / Making the terminal ‘+’ or ‘!!’ optional in order to ensure a pattern broad enough to match a generic bullet. / A use case here is to join a generic head ‘foo’, for instance, from a task head ‘foo+’, in order to task ‘foo’ for action. + Set `p` to broadened to division titling( `p` ). : see `^^broadened to division titling\( pattern \)$` + Anchor `p` by appending ‘$$’. return( `p` ) broadened to division titling( p ) / Returns the given pattern `p` broadened to match division titling. + Anchor `p` by prepending ‘^ *’. + Ensure that `p` functions in *case insensitive* mode (`i`). : re `\*case insensitive\* mode` see https://perldoc.perl.org/perlreref.html#OPERATORS return( `p` ) ancestor qualification - An indicator of an ancestor of the principal fractum. - It indicates the ancestor by the pattern of its text.   ───╴‘@’╶── gap ──╴‘`’╶── pattern ──╴‘`’╶───▶ - Where multiple ancestor qualifications appear in series, each successor indicates an ancestor of the one indicated by its predecessor. document qualification - An indicator of the document of the principal fractum.   ───╴‘@’╶── gap ─── URI reference ────▶ : re `URI reference` see https://tools.ietf.org/html/rfc3986#section-4.1 ━━━━━━━━━━━━━━━ Generic point ─────────────── / A material point. - A point with a bullet outside the form of any specialized material point. - Otherwise a generic point is largely free form. - Its bullet is conditioned only by the basic constraints. : re `basic constraints` see `(basic constraints) ` @ `^^ Bullet$` - Likewise its descriptor, which may also be omitted. : re `Likewise its descriptor` see `most descriptors are largely free form.$` @ `^^ Descriptor$` ━━━━━━━━━━━━━━━━━━━ Indentation blind ─────────────────── / Part of a descriptor. - A sequence of lines each headed by a single no-break space (A0) and thereby excluded from the Breccian rules of indentation. : see `^^character identification$` @ `^^ Notes$` -   ┌───╴◀────────┐   │ │   start ┊ │ inline │   of ┊╶─── A0 ──┬─┴─ character ─┴─┬───▶   line ┊ │ │   └─────────────────┘ diagram, The form of each line in a blind. This diagram is itself an example of a blind comprising six lines. - Regardless of its indentation, a blind does not interrupt the fractal head in which it occurs; rather the head continues (blindly in regard to indentation) through the blind. ━━━━━━━━━ Jointer ───────── - An associative reference with a referential command of `join`. - In effect it stands for the fractal body of its referent. - Any referrer clause in a jointer indicates the referrer in particular as the rationale for writing the jointer into the text. effect - The effect is located in the simulacrum. - There each parent of the jointer gains for a child each child of the referent that does not duplicate a pre-existing child. / Not to imply that the text would be presentable in this form. / If in the source code the referent fractum itself has a jointer as its child, then the effect will apply recursively. - By the same token, the children of the referent gain for a parent each parent of the jointer that does not duplicate a pre-existing parent. / Again, the effect here is recursive. - In both cases, the duplication test ignores variations in commentary and whitespacing. ━━━━━━━━━━━━━━━━━━ Pattern matching ────────────────── - Matching character sequences with regular expressions. pattern - The form of a pattern is a Perl-compatible regular expression modified as follows. : re `Perl compatible regular expression` see https://perldoc.perl.org/perlreref.html • `\t` symbolizes not a tab, but one unit of perfect indentation. • `^^` expands to `^\t*`, an anchored, leading sequence of perfect indentation. - To put an actual `^^` in the pattern, insert a regexp comment, as with `^(?#)^`. • `$$` expands to `(?: +\\(?: .*)?)?$`, allowing for inline commentary and ignoring it. - To put an actual `$$` in the pattern, insert a regexp comment, as with `$(?#)$`. • Literal backquote characters ‘`’ are forbidden. - Patterns in Breccia are formally delimited using backquote characters ‘`’. - To put a backquote character ‘`’ in a pattern, escape it with a backslash ‘\`’. / Of course, backslashes themselves remain escapable, too. / The trailing backquote delimiter in pattern `foo\\`, for example, is not escaped by the preceding backslash because the backslash itself is escaped. • Breccian inline commentary is forbidden. - No start sequence of inline commentary may appear in the pattern. / For example `·\·` or `·\\·`, where each ‘·’ stands for a space character. - Replace it with an equivalent. / For example `··` and `·\N{U+005C}·` respectively. - Patterns function in multiline mode, aka option `m`. : re `(multiline mode).+(option \`m\`)` see https://perldoc.perl.org/perlreref.html#OPERATORS literalized pattern( string ) / Returns the given string as a literally enquoted pattern, as defined for Perl `quotemeta`. : re `quotemeta` see https://perldoc.perl.org/functions/quotemeta.html ━━━━━━━ Point ─────── / A body fractum. - The more common of the body fractum types. : re `body fractum types` see `^^typology$` @ `^^ Fractum$` - Its head comprises a perfectly indented bullet, and often a descriptor.   start ┊ perfect ┊ head successor,   of ┊╶─── indentation ─── bullet ──┬── descriptor ──┬───▶ ┊ or end of document   line ┊ │ │ ┊   └────────────────┘ : re `head successor` see `^^\| the head successor$` @ `^^ Fractum$` diagram, The form of a point head. - The internal form of the bullet, the internal form of the descriptor, and whether the descriptor may be omitted all depend on the type of point. : re `type of point` see `^^typology$` @ `^^ Fractum$` ━━━━━━━━━ Pointer ───────── - An associative reference with a referential command of `see`. - Its only effect is to form a reference. ━━━━━━━━━━━━ Privatizer ──────────── / A command point. - It marks its parent, together with all simulacral descendants, as private fracta. - Its descriptor has this form:   ───╴‘private’╶────▶ diagram, The form of the descriptor in a privatizer. ━━━━━━━━━━━━ Simulacrum ──────────── - A simulacrum is the dynamic, runtime form of a Breccian text, as opposed to the static, written form of its source code. - Initially equal to the source text, the simulacral text is transformed at runtime by the effect of embedded command points. default referent: source code or simulacrum? - Throughout the language definition, the default for formal referents is the source code. - Where it might otherwise be questioned whether the definition is referring to the source versus the simulacral text, it is taken as referring to the source text. ━━━━━━━━━━━━ Task point ──────────── / A specialized material point. - A point with a bullet comprising ‘+’, or ending with ‘+’. - It describes work to be done or undertaken. / After the definition of ‘task’ in the Oxford English Dictionary. : see https://www.lexico.com/en/definition/task \ Defining a specialized point for tasking is justified by the Breccian purpose of drafting, \ for which inline tasking is an important capability. \ re `purpose of drafting` see `for outlining and drafting` @ README.html ━━━━━━━━━━━━ Whitespace ──────────── / A class of character. allowed whitespace : see `^^character identification$` @ `^^ Notes$` • space (20) • newline (A, D) • no-break space (A0) as described for use in bullets and indentation blinds \ Allowing any other horizontal whitespace (9, 2000-200A, 202F, 205F, 3000) \ would be too confusing in Breccia, where indentation determines syntax. perfect indentation - Perfect indentation comes at the start of a line. - It comprises zero or more segments of space characters, each four in length.   ┌───────────╴◀────────────┐   start ┊ │ │   of ┊╶──┬─┴─╴‘ ’╶─╴‘ ’╶─╴‘ ’╶─╴‘ ’╶─┴─┬───▶   line ┊ │ │   └─────────────────────────────┘ ━━━━━━━ Notes ─────── character identification - Characters are here identified by the hexadecimal codes of the Unicode standard. : re `Unicode standard` see https://www.unicode.org/standard/standard.html \ [‘commentary’] \ - It comprises commentary, but not necessarily a comment. \ - Rather it might be only part of a larger comment that extends across several lines. \ - A comment might begin as inline commentary, for example, then continue as block commentary. \ [graphical syntax notation] \ - The present text uses syntax diagrams because it is aimed at Breccian authors in general, \ who are not expected to be comfortable with a textual notation such as Backus-Naur Form. \ Copyright © 2019-2020 Michael Allan. Licence MIT.