/
STD.pm6
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STD.pm6
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# STD.pm
#
# Copyright 2007-2010, Larry Wall
#
# You may copy this software under the terms of the Artistic License,
# version 2.0 or later.
grammar STD:ver<6.0.0.alpha>:auth<http://perl.org>;
use STDStash;
use NAME;
package DEBUG {
our $autolexer = False;
our $symtab = False;
our $fixed_length = False;
our $fates = False;
our $longest_token_pattern_generation = False;
our $EXPR = False;
our $matchers = False;
our $trace_call = False;
our $cursors = False;
our $try_processing = False;
our $mixins = False;
our $callm_show_subnames = False;
our $use_color = False;
}
our $ALL;
=begin comment
Contextuals used in STD
=======================
# per parse
my $*ACTIONS; # class or object which defines reduce actions
my $*SETTINGNAME; # name of core setting
my $*TMP_PREFIX; # where to put tmp files
my @*MEMOS; # per-position info such as ws and line number
my $*HIGHWATER; # where we were last looking for things
my $*HIGHMESS; # current parse failure message
my $*HIGHEXPECT; # things we were looking for at the bleeding edge
my $*IN_PANIC; # don't panic recursively
# symbol table management
our $ALL; # all the stashes, keyed by id
my $*CORE; # the CORE scope
my $*SETTING; # the SETTING scope
my $*GLOBAL; # the GLOBAL scope
my $*PROCESS; # the PROCESS scope
my $*UNIT; # the UNIT scope
my $*CURLEX; # current lexical scope info
my $*CURPKG; # current package scope
my %*MYSTERY; # names we assume may be post-declared functions
# tree attributes, marked as propagating up (u) down (d) or up-and-down (u/d)
my %*LANG; # (d) braided languages: MAIN, Q, Regex, etc
my $*IN_DECL; # (d) a declarator is looking for a name to declare
my $*SCOPE = ""; # (d) which scope declarator we're under
my $*MULTINESS; # (d) which multi declarator we're under
my $*PKGDECL ::= ""; # (d) current package declarator
my $*NEWPKG; # (u/d) new package being declared
my $*NEWLEX; # (u/d) new lex info being declared
my $*DECLARAND; # (u/d) new object associated with declaration
my $*GOAL ::= "(eof)"; # (d) which special terminator we're most wanting
my $*IN_REDUCE; # (d) attempting to parse an [op] construct
my $*IN_META; # (d) parsing a metaoperator like [..]
my $*QUASIMODO; # (d) don't carp about quasi variables
my $*LEFTSIGIL; # (u) sigil of LHS for item vs list assignment
my $*QSIGIL; # (d) sigil of current interpolation
my $*INVOCANT_OK; # (d) parsing a list that allows an invocant
my $*INVOCANT_IS; # (u) invocant of args match
my $*BORG; # (u/d) who to blame if we're missing a block
=end comment
=begin notes
Some rules are named by syntactic category plus an additional symbol
specified in adverbial form, either in bare :name form or in :sym<name>
form. (It does not matter which form you use for identifier symbols,
except that to specify a symbol "sym" you must use the :sym<sym> form
of adverb.) If you use the <sym> rule within the rule, it will parse the
symbol at that point. At the final reduction point of a rule, if $sym
has been set, that is used as the final symbol name for the rule. This
need not match the symbol specified as part the rule name; that is just
for disambiguating the name. However, if no $sym is set, the original
symbol will be used by default.
Note that some of these rules are written strangely because we're
still bootstrapping via a preprocessor, gimme5. For instance,
blocks that contain nested braces are delimited by double braces
so that the preprocessor does not need to parse Perl 6 code.
This grammar relies on transitive longest-token semantics, though
initially we made a feeble attempt to order rules so a procedural
interpretation of alternation could usually produce a correct parse.
(This is becoming less true over time.)
=end notes
method p6class () { ::STD::P6 }
method TOP ($STOP = '') {
my $lang = self.cursor_fresh( self.p6class );
if $STOP {
my $*GOAL ::= $STOP;
$lang.unitstop($STOP).comp_unit;
}
else {
$lang.comp_unit;
}
}
##############
# Precedence #
##############
# The internal precedence levels are *not* part of the public interface.
# The current values are mere implementation; they may change at any time.
# Users should specify precedence only in relation to existing levels.
constant %term = (:dba('term') , :prec<z=>);
constant %methodcall = (:dba('methodcall') , :prec<y=>, :assoc<unary>, :uassoc<left>, :fiddly, :!pure);
constant %autoincrement = (:dba('autoincrement') , :prec<x=>, :assoc<unary>, :uassoc<non>, :!pure);
constant %exponentiation = (:dba('exponentiation') , :prec<w=>, :assoc<right>, :pure);
constant %symbolic_unary = (:dba('symbolic unary') , :prec<v=>, :assoc<unary>, :uassoc<left>, :pure);
constant %multiplicative = (:dba('multiplicative') , :prec<u=>, :assoc<left>, :pure);
constant %additive = (:dba('additive') , :prec<t=>, :assoc<left>, :pure);
constant %replication = (:dba('replication') , :prec<s=>, :assoc<left>, :pure);
constant %concatenation = (:dba('concatenation') , :prec<r=>, :assoc<list>, :pure);
constant %junctive_and = (:dba('junctive and') , :prec<q=>, :assoc<list>, :pure);
constant %junctive_or = (:dba('junctive or') , :prec<p=>, :assoc<list>, :pure);
constant %named_unary = (:dba('named unary') , :prec<o=>, :assoc<unary>, :uassoc<left>, :pure);
constant %structural = (:dba('structural infix'), :prec<n=>, :assoc<non>, :diffy);
constant %chaining = (:dba('chaining') , :prec<m=>, :assoc<chain>, :diffy, :iffy, :pure);
constant %tight_and = (:dba('tight and') , :prec<l=>, :assoc<list>);
constant %tight_or = (:dba('tight or') , :prec<k=>, :assoc<list>);
constant %conditional = (:dba('conditional') , :prec<j=>, :assoc<right>, :fiddly);
constant %item_assignment = (:dba('item assignment') , :prec<i=>, :assoc<right>, :!pure);
constant %list_assignment = (:dba('list assignment') , :prec<i=>, :assoc<right>, :sub<e=>, :fiddly, :!pure);
constant %loose_unary = (:dba('loose unary') , :prec<h=>, :assoc<unary>, :uassoc<left>, :pure);
constant %comma = (:dba('comma') , :prec<g=>, :assoc<list>, :nextterm<nulltermish>, :fiddly, :pure);
constant %list_infix = (:dba('list infix') , :prec<f=>, :assoc<list>, :pure);
constant %list_prefix = (:dba('list prefix') , :prec<e=>, :assoc<unary>, :uassoc<left>);
constant %loose_and = (:dba('loose and') , :prec<d=>, :assoc<list>);
constant %loose_or = (:dba('loose or') , :prec<c=>, :assoc<list>);
constant %sequencer = (:dba('sequencer') , :prec<b=>, :assoc<list>, :nextterm<statement>, :fiddly);
constant %LOOSEST = (:dba('LOOSEST') , :prec<a=!>);
constant %terminator = (:dba('terminator') , :prec<a=>, :assoc<list>);
# "epsilon" tighter than terminator
#constant $LOOSEST = %LOOSEST<prec>;
constant $LOOSEST = "a=!"; # XXX preceding line is busted
constant $item_assignment_prec = 'i=';
constant $methodcall_prec = 'y=';
##############
# Categories #
##############
# Categories are designed to be easily extensible in derived grammars
# by merely adding more rules in the same category. The rules within
# a given category start with the category name followed by a differentiating
# adverbial qualifier to serve (along with the category) as the longer name.
# The endsym context, if specified, says what to implicitly check for in each
# rule right after the initial <sym>. Normally this is used to make sure
# there's appropriate whitespace. # Note that endsym isn't called if <sym>
# isn't called.
my $*endsym = "null";
my $*endargs = -1;
proto token category {*}
token category:category { <sym> }
token category:sigil { <sym> }
proto token sigil {*}
token category:twigil { <sym> }
proto token twigil {*}
token category:special_variable { <sym> }
proto token special_variable {*}
token category:comment { <sym> }
proto token comment {*}
token category:version { <sym> }
proto token version {*}
token category:module_name { <sym> }
proto token module_name {*}
token category:value { <sym> }
proto token value {*}
token category:term { <sym> }
proto token term {*}
token category:strtonum { <sym> }
proto token strtonum {*}
token category:quote { <sym> }
proto token quote {*}
token category:prefix { <sym> }
proto token prefix {*}
token category:infix { <sym> }
proto token infix {*}
token category:postfix { <sym> }
proto token postfix {*}
token category:dotty { <sym> }
proto token dotty {*}
token category:circumfix { <sym> }
proto token circumfix {*}
token category:postcircumfix { <sym> }
proto token postcircumfix {*}
token category:quote_mod { <sym> }
proto token quote_mod {*}
token category:trait_mod { <sym> }
proto token trait_mod {*}
token category:type_declarator { <sym> }
proto token type_declarator {*}
token category:scope_declarator { <sym> }
proto token scope_declarator {*}
token category:package_declarator { <sym> }
proto token package_declarator {*}
token category:multi_declarator { <sym> }
proto token multi_declarator {*}
token category:routine_declarator { <sym> }
proto token routine_declarator {*}
token category:regex_declarator { <sym> }
proto token regex_declarator {*}
token category:statement_prefix { <sym> }
proto rule statement_prefix {*}
token category:statement_control { <sym> }
proto rule statement_control {*}
token category:statement_mod_cond { <sym> }
proto rule statement_mod_cond {*}
token category:statement_mod_loop { <sym> }
proto rule statement_mod_loop {*}
token category:infix_prefix_meta_operator { <sym> }
proto token infix_prefix_meta_operator {*}
# NIECZA no support for protorx with arguments (since arguments defeat LTM,
# I have no clue what this should mean)
# token category:infix_postfix_meta_operator { <sym> }
# proto token infix_postfix_meta_operator ($op) {*}
token category:infix_circumfix_meta_operator { <sym> }
proto token infix_circumfix_meta_operator {*}
token category:postfix_prefix_meta_operator { <sym> }
proto token postfix_prefix_meta_operator {*}
token category:prefix_postfix_meta_operator { <sym> }
proto token prefix_postfix_meta_operator {*}
token category:prefix_circumfix_meta_operator { <sym> }
proto token prefix_circumfix_meta_operator {*}
token category:terminator { <sym> }
proto token terminator {*}
token unspacey { <.unsp>? }
token begid { <?before \w> }
token endid { <?before <-[ \- \' \w ]> > }
token spacey { <?before <[ \s \# ]> > }
token nofun { <!before '(' | '.(' | '\\' | '\'' | '-' | "'" | \w > }
# Note, don't reduce on a bare sigil unless you don't want a twigil or
# you otherwise don't care what the longest token is.
token sigil:sym<$> { <sym> }
token sigil:sym<@> { <sym> }
token sigil:sym<%> { <sym> }
token sigil:sym<&> { <sym> }
token twigil:sym<.> { <sym> <.begid> }
token twigil:sym<!> { <sym> <.begid> }
token twigil:sym<^> { <sym> <.begid> }
token twigil:sym<:> { <sym> <.begid> }
token twigil:sym<*> { <sym> <.begid> }
token twigil:sym<?> { <sym> <.begid> }
token twigil:sym<=> { <sym> <.begid> }
token twigil:sym<~> { <sym> <.begid> }
# overridden in subgrammars
token stopper { <!> }
# hopefully we can include these tokens in any outer LTM matcher
regex stdstopper {
:temp $*STUB = return self if @*MEMOS[self.pos]<endstmt> :exists;
:dba('standard stopper')
[
| <?terminator>
| <?unitstopper>
| <?before <stopper> >
| $ # unlikely, check last (normal LTM behavior)
]
{ @*MEMOS[$¢.pos]<endstmt> = @*MEMOS[$¢.pos] || 1; }
}
token longname {
<name> {} [ <?before ':' <[ a..z A..Z _ \< \[ \« ]>> <colonpair> ]*
}
token name {
[
| <identifier> <morename>*
| <morename>+
]
}
token morename {
:my $*QSIGIL ::= '';
'::'
[
|| <?before '(' | <alpha> >
[
| <identifier>
| :dba('indirect name') '(' ~ ')' <EXPR>
]
|| <?before '::'> <.panic: "Name component may not be null">
]?
}
##############################
# Quote primitives #
##############################
# XXX should eventually be derived from current Unicode tables.
constant %open2close = (
"\x0028" => "\x0029",
"\x003C" => "\x003E",
"\x005B" => "\x005D",
"\x007B" => "\x007D",
"\x00AB" => "\x00BB",
"\x0F3A" => "\x0F3B",
"\x0F3C" => "\x0F3D",
"\x169B" => "\x169C",
"\x2018" => "\x2019",
"\x201A" => "\x2019",
"\x201B" => "\x2019",
"\x201C" => "\x201D",
"\x201E" => "\x201D",
"\x201F" => "\x201D",
"\x2039" => "\x203A",
"\x2045" => "\x2046",
"\x207D" => "\x207E",
"\x208D" => "\x208E",
"\x2208" => "\x220B",
"\x2209" => "\x220C",
"\x220A" => "\x220D",
"\x2215" => "\x29F5",
"\x223C" => "\x223D",
"\x2243" => "\x22CD",
"\x2252" => "\x2253",
"\x2254" => "\x2255",
"\x2264" => "\x2265",
"\x2266" => "\x2267",
"\x2268" => "\x2269",
"\x226A" => "\x226B",
"\x226E" => "\x226F",
"\x2270" => "\x2271",
"\x2272" => "\x2273",
"\x2274" => "\x2275",
"\x2276" => "\x2277",
"\x2278" => "\x2279",
"\x227A" => "\x227B",
"\x227C" => "\x227D",
"\x227E" => "\x227F",
"\x2280" => "\x2281",
"\x2282" => "\x2283",
"\x2284" => "\x2285",
"\x2286" => "\x2287",
"\x2288" => "\x2289",
"\x228A" => "\x228B",
"\x228F" => "\x2290",
"\x2291" => "\x2292",
"\x2298" => "\x29B8",
"\x22A2" => "\x22A3",
"\x22A6" => "\x2ADE",
"\x22A8" => "\x2AE4",
"\x22A9" => "\x2AE3",
"\x22AB" => "\x2AE5",
"\x22B0" => "\x22B1",
"\x22B2" => "\x22B3",
"\x22B4" => "\x22B5",
"\x22B6" => "\x22B7",
"\x22C9" => "\x22CA",
"\x22CB" => "\x22CC",
"\x22D0" => "\x22D1",
"\x22D6" => "\x22D7",
"\x22D8" => "\x22D9",
"\x22DA" => "\x22DB",
"\x22DC" => "\x22DD",
"\x22DE" => "\x22DF",
"\x22E0" => "\x22E1",
"\x22E2" => "\x22E3",
"\x22E4" => "\x22E5",
"\x22E6" => "\x22E7",
"\x22E8" => "\x22E9",
"\x22EA" => "\x22EB",
"\x22EC" => "\x22ED",
"\x22F0" => "\x22F1",
"\x22F2" => "\x22FA",
"\x22F3" => "\x22FB",
"\x22F4" => "\x22FC",
"\x22F6" => "\x22FD",
"\x22F7" => "\x22FE",
"\x2308" => "\x2309",
"\x230A" => "\x230B",
"\x2329" => "\x232A",
"\x23B4" => "\x23B5",
"\x2768" => "\x2769",
"\x276A" => "\x276B",
"\x276C" => "\x276D",
"\x276E" => "\x276F",
"\x2770" => "\x2771",
"\x2772" => "\x2773",
"\x2774" => "\x2775",
"\x27C3" => "\x27C4",
"\x27C5" => "\x27C6",
"\x27D5" => "\x27D6",
"\x27DD" => "\x27DE",
"\x27E2" => "\x27E3",
"\x27E4" => "\x27E5",
"\x27E6" => "\x27E7",
"\x27E8" => "\x27E9",
"\x27EA" => "\x27EB",
"\x2983" => "\x2984",
"\x2985" => "\x2986",
"\x2987" => "\x2988",
"\x2989" => "\x298A",
"\x298B" => "\x298C",
"\x298D" => "\x298E",
"\x298F" => "\x2990",
"\x2991" => "\x2992",
"\x2993" => "\x2994",
"\x2995" => "\x2996",
"\x2997" => "\x2998",
"\x29C0" => "\x29C1",
"\x29C4" => "\x29C5",
"\x29CF" => "\x29D0",
"\x29D1" => "\x29D2",
"\x29D4" => "\x29D5",
"\x29D8" => "\x29D9",
"\x29DA" => "\x29DB",
"\x29F8" => "\x29F9",
"\x29FC" => "\x29FD",
"\x2A2B" => "\x2A2C",
"\x2A2D" => "\x2A2E",
"\x2A34" => "\x2A35",
"\x2A3C" => "\x2A3D",
"\x2A64" => "\x2A65",
"\x2A79" => "\x2A7A",
"\x2A7D" => "\x2A7E",
"\x2A7F" => "\x2A80",
"\x2A81" => "\x2A82",
"\x2A83" => "\x2A84",
"\x2A8B" => "\x2A8C",
"\x2A91" => "\x2A92",
"\x2A93" => "\x2A94",
"\x2A95" => "\x2A96",
"\x2A97" => "\x2A98",
"\x2A99" => "\x2A9A",
"\x2A9B" => "\x2A9C",
"\x2AA1" => "\x2AA2",
"\x2AA6" => "\x2AA7",
"\x2AA8" => "\x2AA9",
"\x2AAA" => "\x2AAB",
"\x2AAC" => "\x2AAD",
"\x2AAF" => "\x2AB0",
"\x2AB3" => "\x2AB4",
"\x2ABB" => "\x2ABC",
"\x2ABD" => "\x2ABE",
"\x2ABF" => "\x2AC0",
"\x2AC1" => "\x2AC2",
"\x2AC3" => "\x2AC4",
"\x2AC5" => "\x2AC6",
"\x2ACD" => "\x2ACE",
"\x2ACF" => "\x2AD0",
"\x2AD1" => "\x2AD2",
"\x2AD3" => "\x2AD4",
"\x2AD5" => "\x2AD6",
"\x2AEC" => "\x2AED",
"\x2AF7" => "\x2AF8",
"\x2AF9" => "\x2AFA",
"\x2E02" => "\x2E03",
"\x2E04" => "\x2E05",
"\x2E09" => "\x2E0A",
"\x2E0C" => "\x2E0D",
"\x2E1C" => "\x2E1D",
"\x2E20" => "\x2E21",
"\x3008" => "\x3009",
"\x300A" => "\x300B",
"\x300C" => "\x300D",
"\x300E" => "\x300F",
"\x3010" => "\x3011",
"\x3014" => "\x3015",
"\x3016" => "\x3017",
"\x3018" => "\x3019",
"\x301A" => "\x301B",
"\x301D" => "\x301E",
"\xFD3E" => "\xFD3F",
"\xFE17" => "\xFE18",
"\xFE35" => "\xFE36",
"\xFE37" => "\xFE38",
"\xFE39" => "\xFE3A",
"\xFE3B" => "\xFE3C",
"\xFE3D" => "\xFE3E",
"\xFE3F" => "\xFE40",
"\xFE41" => "\xFE42",
"\xFE43" => "\xFE44",
"\xFE47" => "\xFE48",
"\xFE59" => "\xFE5A",
"\xFE5B" => "\xFE5C",
"\xFE5D" => "\xFE5E",
"\xFF08" => "\xFF09",
"\xFF1C" => "\xFF1E",
"\xFF3B" => "\xFF3D",
"\xFF5B" => "\xFF5D",
"\xFF5F" => "\xFF60",
"\xFF62" => "\xFF63",
);
constant %close2open = invert %open2close;
# assumes whitespace is eaten already
method peek_delimiters {
my $pos = self.pos;
my $startpos = $pos;
my $char = substr(self.orig,$pos++,1);
if $char ~~ /^\s$/ {
self.panic("Whitespace character is not allowed as delimiter"); # "can't happen"
}
elsif $char ~~ /^\w$/ {
self.panic("Alphanumeric character is not allowed as delimiter");
}
elsif %close2open{$char} {
self.panic("Use of a closing delimiter for an opener is reserved");
}
elsif $char eq ':' {
self.panic("Colons may not be used to delimit quoting constructs");
}
my $rightbrack = %open2close{$char};
if not defined $rightbrack {
return $char, $char;
}
while substr(self.orig,$pos,1) eq $char {
$pos++;
}
my $len = $pos - $startpos;
my $start = $char x $len;
my $stop = $rightbrack x $len;
return $start, $stop;
}
role startstop[$start,$stop] {
token starter { $start }
token stopper { $stop }
} # end role
role stop[$stop] {
token starter { <!> }
token stopper { $stop }
} # end role
role unitstop[$stop] {
token unitstopper { $stop }
} # end role
token unitstopper { $ }
method balanced ($start,$stop) { self.mixin( STD::startstop[$start,$stop] ); }
method unbalanced ($stop) { self.mixin( STD::stop[$stop] ); }
method unitstop ($stop) { self.mixin( STD::unitstop[$stop] ); }
method truly ($bool,$opt) {
return self if $bool;
self.sorry("Can't negate $opt adverb");
self;
}
token charname {
[
| <radint>
| <alpha> .*? <?before \s*[ ',' | '#' | ']']>
] || <.sorry: "Unrecognized character name"> .*?<?terminator>
}
token charnames { \s* [<charname><.ws>] ** [','\s*] }
token charspec {
[
| :dba('character name') '[' ~ ']' <charnames>
| \d+
| <[ ?..Z \\.._ ]>
| <?> <.sorry: "Unrecognized \\c character"> .
]
}
proto token backslash {*}
proto token escape {*}
token starter { <!> }
token escape:none { <!> }
# and this is what makes nibbler polymorphic...
method nibble ($lang) {
self.cursor_fresh($lang).nibbler;
}
# note: polymorphic over many quote languages, we hope
token nibbler {
:my $text = '';
:my $from = self.pos;
:my $to = $from;
:my @nibbles = ();
:my $multiline = 0;
# { self.from = self.pos; } NIECZA
[ <!before <stopper> >
[
|| <starter> <nibbler> <stopper>
{
push @nibbles, $¢.makestr(TEXT => $text, _from => $from, _pos => $to ) if $from != $to;
my $n = $<nibbler>[*-1]<nibbles>;
my @n = @$n;
push @nibbles, $<starter>;
push @nibbles, @n;
push @nibbles, $<stopper>;
$text = '';
$to = $from = $¢.pos;
}
|| <escape> {
push @nibbles, $¢.makestr(TEXT => $text, _from => $from, _pos => $to ) if $from != $to;
push @nibbles, $<escape>[*-1];
$text = '';
$to = $from = $¢.pos;
}
|| .
{{
my $ch = substr(self.orig, $¢.pos-1, 1);
$text ~= $ch;
$to = $¢.pos;
if $ch ~~ "\n" {
$multiline++;
}
}}
]
]*
{
push @nibbles, $¢.makestr(TEXT => $text, _from => $from, _pos => $to ) if $from != $to or !@nibbles;
$<nibbles> = @nibbles;
$.pos = $¢.pos;
$<nibbler> :delete;
$<escape> :delete;
$<starter> :delete;
$<stopper> :delete;
$*LAST_NIBBLE = $¢;
$*LAST_NIBBLE_MULTILINE = $¢ if $multiline;
}
}
token babble ($l) {
:my $lang = $l;
:my $start;
:my $stop;
<.ws>
[ <quotepair> <.ws>
{
my $kv = $<quotepair>[*-1];
$lang = ($lang.tweak(| ($kv.<k> => $kv.<v>))
or $lang.sorry("Unrecognized adverb :" ~ $kv.<k> ~ '(' ~ $kv.<v> ~ ')'));
}
]*
$<B> = {
($start,$stop) = $¢.peek_delimiters();
$lang = $start ne $stop ?? $lang.balanced($start,$stop)
!! $lang.unbalanced($stop);
[$lang,$start,$stop];
}
}
our @herestub_queue;
class Herestub {
has $.delim;
has $.orignode;
has $.lang;
method new(:$delim, :$orignode, :$lang) {
my $new = self.CREATE;
$new!delim = $delim;
$new!orignode = $orignode;
$new!lang = $lang;
$new;
}
}
role herestop {
token stopper { ^^ {} $<ws>=(\h*?) $*DELIM \h* <.unv>?? $$ \v? }
}
# XXX be sure to temporize @herestub_queue on reentry to new line of heredocs
method heredoc () {
my $here = self;
while my $herestub = shift @herestub_queue {
my $*DELIM = $herestub.delim;
my $lang = $herestub.lang.mixin( ::herestop );
my $doc;
if ($doc) = $here.nibble($lang) {
$here = $doc.trim_heredoc();
$herestub.orignode<doc> = $doc;
}
else {
self.panic("Ending delimiter $*DELIM not found");
}
}
return self.cursor($here.pos); # return to initial type
}
method herelang () { Any }
token quibble ($l) {
:my ($lang, $start, $stop);
<babble($l)>
{ my $B = $<babble><B>; ($lang,$start,$stop) = @$B; }
$start <nibble($lang)> [ $stop || <.panic: "Couldn't find terminator $stop"> ]
{
if $lang.herelang {
push @herestub_queue,
Herestub.new(
delim => $<nibble><nibbles>[0]<TEXT>,
orignode => $¢,
lang => $lang.herelang,
);
}
}
}
token quotepair {
:my $key;
:my $value;
':'
:dba('colon pair (restricted)')
[
| '!' <identifier> [ <?before '('> <.sorry: "Argument not allowed on negated pair"> <circumfix> ]?
{ $key = $<identifier>.Str; $value = 0; }
| <identifier>
{ $key = $<identifier>.Str; }
[
|| <.unsp>? <?before '('> <circumfix> { $value = $<circumfix>; }
|| { $value = 1; }
]
| $<n>=(\d+) $<id>=(<[a..z]>+) [ <?before '('> <.sorry: "2nd argument not allowed on pair"> <circumfix> ]?
{ $key = $<id>.Str; $value = $<n>.Str; }
]
$<k> = {$key} $<v> = {$value}
}
token quote:sym<' '> { :dba('single quotes') "'" ~ "'" <nibble($¢.cursor_fresh( %*LANG<Q> ).tweak(:q).unbalanced("'"))> }
token quote:sym<" "> { :dba('double quotes') '"' ~ '"' <nibble($¢.cursor_fresh( %*LANG<Q> ).tweak(:qq).unbalanced('"'))> }
token circumfix:sym<« »> { :dba('shell-quote words') '«' ~ '»' <nibble($¢.cursor_fresh( %*LANG<Q> ).tweak(:qq).tweak(:ww).balanced('«','»'))> }
token circumfix:sym«<< >>» { :dba('shell-quote words') '<<' ~ '>>' <nibble($¢.cursor_fresh( %*LANG<Q> ).tweak(:qq).tweak(:ww).balanced('<<','>>'))> }
token circumfix:sym«< >» { :dba('quote words') '<' ~ '>'
[
[ <?before 'STDIN>' > <.obs('<STDIN>', '$' ~ '*IN.lines')> ]? # XXX fake out gimme5
[ <?before '>' > <.obs('<>', "lines() to read input,\n or ('') to represent the null string,\n or () to represent Nil")> ]?
<nibble($¢.cursor_fresh( %*LANG<Q> ).tweak(:q).tweak(:w).balanced('<','>'))>
]
}
##################
# Lexer routines #
##################
token ws {
:temp $*STUB = return self if @*MEMOS[self.pos]<ws> :exists;
:my $startpos = self.pos;
:my $*HIGHEXPECT = {};
:dba('whitespace')
[
| \h+ <![\#\s\\]> { @*MEMOS[$¢.pos]<ws> = $startpos; } # common case
| <?before \w> <?after \w> :::
{ @*MEMOS[$startpos]<ws>:delete; }
<.sorry: "Whitespace is required between alphanumeric tokens"> # must \s+ between words
]
||
[
| <.unsp>
| <.vws> <.heredoc>
| <.unv>
# | $ { $¢.moreinput } NIECZA break inf loop
]*
{
if ($¢.pos == $startpos) {
@*MEMOS[$¢.pos]<ws>:delete;
}
else {
@*MEMOS[$¢.pos]<ws> = $startpos;
@*MEMOS[$¢.pos]<endstmt> = @*MEMOS[$startpos]<endstmt>
if @*MEMOS[$startpos]<endstmt> :exists;
}
}
}
token unsp {
\\ <?before [\s|'#'] >
:dba('unspace')
[
| <.vws>
| <.unv>
# | $ { $¢.moreinput } NIECZA break inf loop
]*
}
token vws {
:dba('vertical whitespace')
[
[
| \v
# | '#DEBUG -1' { say "DEBUG"; $*DEBUG = -1; } \V* \v
| '<<<<<<<' :: <?before [.*? \v '=======']: .*? \v '>>>>>>>' > <.sorry: 'Found a version control conflict marker'> \V* \v
| '=======' :: .*? \v '>>>>>>>' \V* \v # ignore second half
]
]+
}
# We provide two mechanisms here:
# 1) define $*moreinput, or
# 2) override moreinput method
method moreinput () {
$*moreinput.() if $*moreinput;
self;
}
token unv {
:dba('horizontal whitespace')
[
| \h+
| <?before \h* '=' [ \w | '\\'] > ^^ <.pod_comment>
| \h* <comment>
]
}
token comment:sym<#`(...)> {
'#`' :: [ <?opener> || <.panic: "Opening bracket is required for #` comment"> ]
<.quibble($¢.cursor_fresh( %*LANG<Q> ))>
}
token comment:sym<#(...)> {
'#' <?opener>
<.suppose
<quibble($¢.cursor_fresh( %*LANG<Q> ))>
<!before <[,;:]>* \h* [ '#' | $$ ] > # extra stuff on line after closer?
>
<.worry: "Embedded comment seems to be missing backtick"> <!>
}
token comment:sym<#=(...)> {
'#=' <?opener> ::
<quibble($¢.cursor_fresh( %*LANG<Q> ))>
}
token comment:sym<#=> {
'#=' :: $<attachment> = [\N*]
}
token comment:sym<#> {
'#' {} \N*
}
token ident {
<.alpha> \w*
}
token apostrophe {
<[ ' \- ]>
}
token identifier {
<.ident> [ <.apostrophe> <.ident> ]*
}
# XXX We need to parse the pod eventually to support $= variables.
token pod_comment {
^^ \h* '=' <.unsp>?
[
| 'begin' \h+ <identifier> ::
[
|| .*? "\n" [ :r \h* '=' <.unsp>? 'end' \h+ $<identifier> » \N* ]
|| <?{ $<identifier>.Str eq 'END'}> .*
|| { my $id = $<identifier>.Str; self.panic("=begin $id without matching =end $id"); }
]
| 'begin' » :: \h* [ $$ || '#' || <.sorry: "Unrecognized token after =begin"> \N* ]
[ .*? "\n" \h* '=' <.unsp>? 'end' » \N* || { self.panic("=begin without matching =end"); } ]
| 'for' » :: \h* [ <identifier> || $$ || '#' || <.sorry: "Unrecognized token after =for"> \N* ]
[.*? ^^ \h* $$ || .*]
| ::
[ <?before .*? ^^ '=cut' » > <.panic: "Obsolescent pod format, please use =begin/=end instead"> ]?
[<alpha>||\s||<.sorry: "Illegal pod directive">]
\N*
]
}
# suppress fancy end-of-line checking
token embeddedblock {
# encapsulate braided languages
:temp %*LANG;
:my $*SIGNUM;
:my $*GOAL ::= '}';
:temp $*CURLEX;
:dba('embedded block')
<.newlex>
<.finishlex>
'{' :: [ :lang(%*LANG<MAIN>) <statementlist> ]
[ '}' || <.panic: "Unable to parse statement list; couldn't find right brace"> ]
}
token binints { [<.ws><binint><.ws>] ** ',' }
token binint {
<[ 0..1 ]>+ [ _ <[ 0..1 ]>+ ]*
}
token octints { [<.ws><octint><.ws>] ** ',' }
token octint {
<[ 0..7 ]>+ [ _ <[ 0..7 ]>+ ]*
}
token hexints { [<.ws><hexint><.ws>] ** ',' }
token hexint {
<[ 0..9 a..f A..F ]>+ [ _ <[ 0..9 a..f A..F ]>+ ]*
}
token decints { [<.ws><decint><.ws>] ** ',' }
token decint {
\d+ [ _ \d+ ]*
}
token integer {
[
| 0 [ b '_'? <binint>
| o '_'? <octint>
| x '_'? <hexint>
| d '_'? <decint>
| <decint>
<!!{ $¢.worry("Leading 0 does not indicate octal in Perl 6; please use 0o" ~ $<decint>.Str ~ " if you mean that") }>
]
| <decint>
]