/ 
Muldis-D-0.33.0
River stage zero No dependents
/ Muldis::D::Dialect::PTMD_Tiny

NAME

Muldis::D::Dialect::PTMD_Tiny - How to format Plain Text Muldis D

VERSION

This document is Muldis::D::Dialect::PTMD_Tiny version 0.24.0.

PREFACE

This document is part of the Muldis D language specification, whose root document is Muldis::D; you should read that root document before you read this one, which provides subservient details.

DESCRIPTION

This document outlines the grammar of the Plain Text Muldis D dialect named PTMD_Tiny. The fully-qualified name of this Muldis D dialect, in combination with the base language spec it is bundled with, is Muldis_D:'http://muldis.com':'N.N.N':'PTMD_Tiny' (when the bundled base language version is substituted for the N.N.N).

This dialect is designed to exactly match the Muldis D system catalog (the possible representation of Muldis D code that is visible to or updateable by Muldis D programs at runtime) as to what non-critical meta-data it explicitly stores; so code in the PTMD_Tiny dialect should be round-trippable with the system catalog with the result maintaining all the details that were started with. Since it matches the system catalog, this dialect should be able to exactly represent all possible Muldis D base language code (and probably all extensions too), rather than a subset of it. This dialect similarly matches the HDMD_Perl_Tiny dialect, which is documented at Muldis::D::Dialect::HDMD_Perl_Tiny.

This dialect is designed to be as small as possible while meeting the above criteria, and is designed such that a parser that handles all of this dialect can be tiny, hence the dialect's Tiny name. Likewise, a code generator for this dialect from the system catalog can be tiny.

This document mainly just specifies a way to represent Muldis D values as character strings. Since the fundamental way to do data definition in Muldis D is to update catalog (information schema) variables, aka the Muldis D meta-model, which are themselves just data, then this document only needs to tell you how to define values to put in the catalog variables. Defining data types or routines are done by defining catalog values describing them.

See instead Muldis::D::Core for how to actually define the tuples and relations that define your data types and routines and queries and so forth.

See also Muldis::D::Dialect::HDMD_Perl_Tiny and look up its syntax for representing Muldis D literal values, each syntax item typically corresponds to a syntax item in the current document; the other document helps explain the meaning of and further constraints on value specifications than this current document does. The syntax given in the current document primarily tests for well-formedness, not that code is otherwise valid.

Keeping in mind that any Plain Text Muldis D code file has to actually consist of a Muldis D bootloader routine, the following grammar is actually the grammar to parse a bootloader routine, which is simply a series of procedure calls (specifically procedures with no subject-to-update parameters), where earlier procedure calls are to system-defined data-definition routines (their arguments are values to put in the system catalog), and later ones are then to user-defined routines that the earlier statements either loaded or defined.

Now another quality of the PTMD_Tiny dialect is that it is designed to work easily for a single-pass parser, or at least a single-pass lexer; all the context that one needs to know for how to parse or lex any arbitrary substring of code is provided by prior code. Therefore, a PTMD_Tiny parser can easily work on a streaming input like a file-handle where you can't go back earlier in the stream. Often this means a parser can work with little RAM.

Also the dialect is designed that any amount of whitespace can be added or omitted next to most non-alphanumeric characters (which happen to be next to alphanumeric tokens) without that affecting the meaning of the code at all, except obviously for within character string literals. And long binary or character strings can be split into arbitrary-size substrings, without affecting the meaning. And many elements are identified by name rather than ordinal position, so to some degree the order they appear has no effect on the meaning. So programmers can easily format (separate, indent, linewrap, order) code how they like, and making an automated code reformatter shouldn't be difficult. Often, named elements can also be omitted entirely for brevity, in which case the parser would use context to supply default values for those elements. These qualities are all shared by the HDMD_Perl_Tiny dialect too.

GRAMMAR OF TINY PLAIN TEXT MULDIS D

This grammar is formatted as a Perl 6 grammar which could be used to parse it. That said, it is only meant to be illustrative, as only some Muldis D implementations would actually be written in Perl 6 or understand Perl 6 grammars. The following Perl 6 code does successfully compile using the current Perl6::Pugs, though it has not yet been tested for correct execution. Actually, the last several versions were not even tested for being able to compile, but it is assumed they are close to being compilable at least. Any remaining errors should be corrected as soon as possible.

use v6-alpha;

# grammar Muldis_D_PTMD_Tiny:auth<http://muldis.com>:ver<0.24.0>;
grammar Muldis_D_PTMD_Tiny-0.24.0-http://muldis.com;

token bootloader {
    (<language_name>)
    (<bootloader_procedure_call>*)
}

token language_name {
    (Muldis_D)
    <spec_sep>
    <ln_authority>
    <spec_sep>
    <ln_version>
    <spec_sep>
    <ln_dialect>
    <spec_sep>
    <ln_extensions>
}

token ln_authority { <quoted_text_str> }

token ln_version { <quoted_text_str> }

token ln_dialect { <text_delim> (PTMD_Tiny) <text_delim> }

token ln_extensions { <tuple_body> }

token bootloader_procedure_call {
    (boot_call)
    <spec_sep>
    <procedure_name>
    <spec_sep>
    <procedure_args>
}

token procedure_name { <name_chain_body> }

token procedure_args { <tuple_body> }

token literal {
      <scalar_or_qv>
    | <bool>
    | <int>
    | <blob>
    | <text>
    | <tuple_or_qv>
    | <relation_or_qv>
    | <name>
    | <name_chain>
    | <decl_name_chain>
    | <comment>
    | <order>
    | <rat>
    | <rat_round_meth>
}

token scalar_or_qv {
    ((Quasi)? Scalar)
    <spec_sep>
    <scalar_type_name>
    <spec_sep>
    <possrep_name>
    <spec_sep>
    <possrep_attrs>
}

token scalar_type_name { <name_chain_body> }

token possrep_name { <name> }

token possrep_attrs { <tuple_body> }

token bool { (Bool) <spec_sep> (false|true) }

token int {
    (Int)
    <spec_sep>
    (<[1-9A-Z]>)
    <spec_sep>
    (0|\-?<[1-9A-Z]><[0-9A-Z]>*)
}

token blob {
    (Blob)
    <spec_sep>
    (<[137F]>)
    <spec_sep>
    ((<[0-9A-F]>*) (<segment_sep> (<[0-9A-F]>*))*)
}

token text {
    (Text)
    <spec_sep>
    <quoted_text_str>
}

token tuple_or_qv {
    ((Quasi)? Tuple)
    <spec_sep>
    <tuple_body>
}

token relation_or_qv {
      <generic_relation_empty_body_or_qv>
    | <generic_relation_with_tuples_or_qv>
    | <generic_relation_ordered_attr_or_qv>
    | <set_or_qv>
    | <nothing_or_qv>
    | <single_or_qv>
    | <array_or_qv>
    | <bag_or_qv>
}

token generic_relation_empty_body_or_qv {
    ((Quasi)? Relation)
    <spec_sep>
    <list_open>
        (((<name>) <list_sep>)*)
    <list_close>
}

token generic_relation_with_tuples_or_qv {
    ((Quasi)? Relation)
    <spec_sep>
    <list_open>
        (((<tuple_body>) <list_sep>)*)
    <list_close>
}

token generic_relation_ordered_attr_or_qv {
    ((Quasi)? Relation)
    <spec_sep>
    <ord_list_open>
        (((<name>) <list_sep>)*)
    <ord_list_close>
    <spec_sep>
    <list_open>
    ((
        <ord_list_open>
            (((<literal>) <list_sep>)*)
        <ord_list_close> <list_sep>
    )*)
    <list_close>
}

token tuple_body {
    <list_open>
        (((<name> <pair_sep> <literal>) <list_sep>)*)
    <list_close>
}

token set_or_qv {
    ((Quasi)? Set)
    <spec_sep>
    <list_open>
        (((<literal>) <list_sep>)*)
    <list_close>
}

token nothing_or_qv { ((Quasi)? Nothing) }

token single_or_qv {
    ((Quasi)? Single)
    <spec_sep>
    <list_open>
        (<literal>)
    <list_close>
}

token array_or_qv {
    ((Quasi)? Array)
    <spec_sep>
    <ord_list_open>
        (((<literal>) <list_sep>)*)
    <ord_list_close>
}

token bag_or_qv {
      bag_counted_values_or_qv
    | bag_repeated_values_or_qv
}

token bag_counted_values_or_qv {
    ((Quasi)? Bag)
    <spec_sep>
    (count)
    <spec_sep>
    <list_open>
        (((<literal>) <pair_sep> (<count>) <list_sep>)*)
    <list_close>
}

token count {
    (<[1-9A-Z]>)
    <spec_sep>
    (<[1-9A-Z]><[0-9A-Z]>*)
}

token bag_repeated_values_or_qv {
    ((Quasi)? Bag)
    <spec_sep>
    (repeat)
    <spec_sep>
    <list_open>
        (((<literal>) <list_sep>)*)
    <list_close>
}

token list_open { \s* '{' \s* }

token list_close { \s* '}' \s* }

token ord_list_open { \s* '[' \s* }

token ord_list_close { \s* ']' \s* }

token list_sep { \s* ',' \s* }

token pair_sep { \s* '=>' \s* }

token spec_sep { \s* ':' \s* }

token quoted_text_str {
    (<quoted_text_str_seg> (<segment_sep> <quoted_text_str_seg>)*)
}

token segment_sep { \s* '~' \s* }

token quoted_text_str_seg {
    <text_delim>
        (<text_char>*)
    <text_delim>
}

token text_delim { <[']> }

token text_char { ['\b'|'\q'|<-[\\\']>] }

token name { <quoted_text_str> }

token name_chain {
    (NameChain)
    <spec_sep>
    <name_chain_body>
}

token name_chain_body {
      nc_array
    | nc_flat
}

token nc_array {
    <ord_list_open>
        ((<name>) (\s* <nc_elem_sep> \s* (<name>))+)
    <ord_list_close>
}

token nc_flat {
    <text_delim>
        ((<nc_char>*) (<nc_elem_sep> (<nc_char>*))+)
    <text_delim>
}

token nc_elem_sep { '.' }

token nc_char { ['\b'|'\q'|'\p'|<-[\\\'\.]>] }

token decl_name_chain {
    (DeclNameChain)
    <spec_sep>
    <decl_name_chain_body>
}

token decl_name_chain_body {
      dnc_array
    | dnc_flat
}

token dnc_array {
    <ord_list_open>
        (((<name>) (\s* <nc_elem_sep> \s* (<name>))?)?)
    <ord_list_close>
}

token dnc_flat {
    <text_delim>
        (<nc_elem_sep> ((<nc_char>*) <nc_elem_sep>)*)
    <text_delim>
}

token comment {
    (Comment)
    <spec_sep>
    <quoted_text_str>
}

token order { (Order) <spec_sep> (increase|same|decrease|-1|0|1) }

token rat {
      rat_with_radix
    | rat_as_ratio
    | rat_as_float
}

token rat_with_radix {
    (Rat)
    <spec_sep>
    (radix)
    <spec_sep>
    (<[1-9A-Z]>)
    <spec_sep>
    (0|\-?<[1-9A-Z]><[0-9A-Z]>*\.?<[0-9A-Z]>*)
}

token rat_as_ratio {
    (Rat)
    <spec_sep>
    (ratio)
    <spec_sep>
    (<[1-9A-Z]>)
    <spec_sep>
    ((0|\-?<[1-9A-Z]><[0-9A-Z]>*) \s* \/ \s* (<[1-9A-Z]><[0-9A-Z]>*))
}

token rat_as_float {
    (Rat)
    <spec_sep>
    (float)
    <spec_sep>
    (<[1-9A-Z]>)
    <spec_sep>
    ((0|\-?<[1-9A-Z]><[0-9A-Z]>*)
    \s*
    \*
    \s*
    (<[2-9A-Z]><[0-9A-Z]>*)
    \s*
    \^
    \s*
    (0|\-?<[1-9A-Z]><[0-9A-Z]>*))
}

token rat_round_meth {
    (RatRoundMeth)
    <spec_sep>
    (half_down|half_up|half_even|to_floor|to_ceiling|to_zero|to_inf)
}

EXAMPLES

The following are fragments of actual Plain Text Muldis D code.

Muldis_D:'http://muldis.com':'1.2.3':'PTMD_Tiny':{};

boot_call:'sys.std.Core.Cat.create_public_relvar':{ ... };

Scalar:'sys.std.Rational.Type.Rat':'float':{
    'mantissa' => Int:9:45207196,
    'radix'    => Int:9:10,
    'exponent' => Int:9:37,
}

Scalar:'fed.lib.the_db.WeekDay':'name':{
    '' => Text:'monday',
}

Scalar:'fed.lib.the_db.WeekDay':'number':{
    '' => Int:9:5,
}

Bool:true

Int:1:11001001

Int:7:0

Int:7:644

Int:9:-34

Int:9:42

Int:F:DEADBEEF

Int:Z:-HELLOWORLD

Int:3:301

Int:B:A09B

Blob:1:00101110100010

Blob:3:

Blob:F:A705E

Blob:7:523504376

Text:'Ceres'

Text:'サンプル'

Text:''

Text:'Perl'

Tuple:{}

Tuple:{
    'login_name' => Text:'hartmark',
    'login_pass' => Text:'letmein',
    'is_special' => Bool:true,
}

Tuple:{
    'name' => Text:'Michelle',
    'age'  => Int:9:17,
}

Relation:{}

Relation:{ {}, }

Relation:{ 'x', 'y', 'z', }

Relation:{
    {
        'login_name' => Text:'hartmark',
        'login_pass' => Text:'letmein',
        'is_special' => Bool:true,
    },
}

Relation:[ 'name', 'age', ]:{
    [ Text:'Michelle', Int:9:17, ],
}

Set:{
    Text:'Canada',
    Text:'Spain',
    Text:'Jordan',
    Text:'Thailand',
}

Set:{
    Int:9:3,
    Int:9:16,
    Int:9:85,
}

Nothing

Single:{ Text:'2003.07.24' }

Array:[
    Text:'Alphonse',
    Text:'Edward',
    Text:'Winry',
]

Array:[
    Int:9:57,
    Int:9:45,
    Int:9:63,
    Int:9:61,
]

Bag:count:{
    Text:'Apple'  => 9:500,
    Text:'Orange' => 9:300,
    Text:'Banana' => 9:400,
}

Bag:repeat:{
    Text:'Foo',
    Text:'Quux',
    Text:'Foo',
    Text:'Bar',
    Text:'Baz',
    Text:'Baz',
}

'login_pass'

'First Name'

NameChain:['fed'.'data'.'the_db'.'gene'.'sorted_person_name']

NameChain:'fed.data.the_db.stats.samples_by_order'

DeclNameChain:['gene'.'sorted_person_name']

DeclNameChain:'.stats.samples_by_order.'

Comment:'This does something.'

Order:same

Rat:radix:1:-1.1

Rat:radix:9:-1.5

Rat:radix:9:3.14159

Rat:radix:A:0.0

Rat:radix:F:DEADBEEF.FACE

Rat:radix:Z:0.000AZE

Rat:ratio:6:500001/1000

Rat:ratio:B:A09B/A

Rat:float:1:1011101101*10^-11011

Rat:float:9:45207196*10^37

RatRoundMeth:half_up

SEE ALSO

Go to Muldis::D for the majority of distribution-internal references, and Muldis::D::SeeAlso for the majority of distribution-external references.

AUTHOR

Darren Duncan (perl@DarrenDuncan.net)

LICENSE AND COPYRIGHT

This file is part of the formal specification of the Muldis D language.

Muldis D is Copyright © 2002-2008, Darren Duncan.

See the LICENSE AND COPYRIGHT of Muldis::D for details.

TRADEMARK POLICY

The TRADEMARK POLICY in Muldis::D applies to this file too.

ACKNOWLEDGEMENTS

The ACKNOWLEDGEMENTS in Muldis::D apply to this file too.