pt::peg::to::param(n)
okay so bestie, this is pt::peg::to::param 💖 — a page from the Parser Tools manual (the (n) is just the manual section, iykyk). She's a converter, she's book smart, and she's about to make PARAM markup appear out of thin air. Let's get into it.
🌸 NAME 🌸
pt::peg::to::param — PEG Conversion. Write PARAM format ✨
✨ SYNOPSIS ✨
package require Tcl 8.5 9
package require pt::peg::to::param ?1.1?
package require pt::peg
package require pt::pe
pt::peg::to::param reset
pt::peg::to::param configure
pt::peg::to::param configure option
pt::peg::to::param configure option value...
pt::peg::to::param convert serial🦋 DESCRIPTION 🦋
bestie, are you lost?? 😭 Having trouble understanding this document? Say less — go read the overview in the Introduction to Parser Tools. That doc is the entrypoint to the whole entire system this package is part of, no cap. 🫶
So what is this package, actually? It implements the converter from parsing expression grammars to PARAM markup. That's the whole gig. ✨
Where does she live? In the Export section of the Core Layer of Parser Tools, and you can use her two different ways:
- directly with the other packages of this layer, or
- indirectly through the export manager provided by
pt::peg::export.
That second route? It's intented for use in untrusted environments 🙈 and it goes through the corresponding export plugin pt::peg::export::param, which sits between the converter and the export manager like the world's most responsible group-chat moderator. 👑
📸 the doc drops an image reference here: IMAGE: arch_core_eplugins
💅 API 💅
The API this package hands you satisfies the spec of the Converter API found in the Parser Tools Export API specification. It's giving certified. 🎀
pt::peg::to::param reset— this command resets the configuration of the package to its default settings. fresh-start energy, we love a clean slate 🧼pt::peg::to::param configure— this command returns a dictionary containing the current configuration of the package. it's just telling you what's going on 💬pt::peg::to::param configure option— this command returns the current value of the specified configuration option of the package. wondering which options are even legal? read the Options section, bestie 👀pt::peg::to::param configure option value...— this command sets the given configuration options of the package to the specified values. again: for the set of legal options, please read the Options section.pt::peg::to::param convert serial— this command takes the canonical serialization of a parsing expression grammar (as specified in the PEG serialization format section, contained inserial) and generates PARAM markup encoding the grammar, per the current package configuration. the created string is then returned as the result of the command. slay 💅
🎀 OPTIONS 🎀
The converter to PARAM markup recognizes the following configuration variables and changes its behaviour as they specify. 👑
-template string— the value of this configuration variable is a string into which to put the generated text and the other configuration settings. the various locations for user-data are expected to be specified with the placeholders listed below. the default value is"@code@".@user@— to be replaced with the value of the configuration variable-user.@format@— to be replaced with the constantPARAM.@file@— to be replaced with the value of the configuration variable-file.@name@— to be replaced with the value of the configuration variable-name.@code@— to be replaced with the generated text.
-name string— the value of this configuration variable is the name of the grammar for which the conversion is run. the default value isa_pe_grammar.-user string— the value of this configuration variable is the name of the user for which the conversion is run. the default value isunknown.-file string— the value of this configuration variable is the name of the file or other entity from which the grammar came, for which the conversion is run. the default value isunknown.
🌈 PARAM CODE REPRESENTATION OF PARSING EXPRESSION GRAMMARS 🌈
The PARAM code representation of parsing expression grammars is assembler-like text using the instructions of the virtual machine documented in the PackRat Machine Specification, plus a few more for control flow: jump ok, jump fail, call symbol, return. 🧚
ngl, it is not really useful — except possibly as a tool demonstrating how a grammar is compiled in general, without getting distracted by the incidentals of a framework, i.e. like the supporting C and Tcl code generated by the other PARAM-derived formats. 💀
It has no direct formal specification beyond what was said above. periodt. ✨
🍓 EXAMPLE 🍓
Assuming the following PEG for simple mathematical expressions:
PEG calculator (Expression)
Digit <- '0'/'1'/'2'/'3'/'4'/'5'/'6'/'7'/'8'/'9' ;
Sign <- '-' / '+' ;
Number <- Sign? Digit+ ;
Expression <- Term (AddOp Term)* ;
MulOp <- '*' / '/' ;
Term <- Factor (MulOp Factor)* ;
AddOp <- '+'/'-' ;
Factor <- '(' Expression ')' / Number ;
END;one possible PARAM serialization for it is:
# -*- text -*-
# Parsing Expression Grammar 'TEMPLATE'.
# Generated for unknown, from file 'TEST'
#
# Grammar Start Expression
#
<<MAIN>>:
call sym_Expression
halt
#
# value Symbol 'AddOp'
#
sym_AddOp:
# /
# '-'
# '+'
symbol_restore AddOp
found! jump found_7
loc_push
call choice_5
fail! value_clear
ok! value_leaf AddOp
symbol_save AddOp
error_nonterminal AddOp
loc_pop_discard
found_7:
ok! ast_value_push
return
choice_5:
# /
# '-'
# '+'
error_clear
loc_push
error_push
input_next "t -"
ok! test_char "-"
error_pop_merge
ok! jump oknoast_4
loc_pop_rewind
loc_push
error_push
input_next "t +"
ok! test_char "+"
error_pop_merge
ok! jump oknoast_4
loc_pop_rewind
status_fail
return
oknoast_4:
loc_pop_discard
return
#
# value Symbol 'Digit'
#
sym_Digit:
# /
# '0'
# '1'
# '2'
# '3'
# '4'
# '5'
# '6'
# '7'
# '8'
# '9'
symbol_restore Digit
found! jump found_22
loc_push
call choice_20
fail! value_clear
ok! value_leaf Digit
symbol_save Digit
error_nonterminal Digit
loc_pop_discard
found_22:
ok! ast_value_push
return
choice_20:
# /
# '0'
# '1'
# '2'
# '3'
# '4'
# '5'
# '6'
# '7'
# '8'
# '9'
error_clear
loc_push
error_push
input_next "t 0"
ok! test_char "0"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 1"
ok! test_char "1"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 2"
ok! test_char "2"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 3"
ok! test_char "3"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 4"
ok! test_char "4"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 5"
ok! test_char "5"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 6"
ok! test_char "6"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 7"
ok! test_char "7"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 8"
ok! test_char "8"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
loc_push
error_push
input_next "t 9"
ok! test_char "9"
error_pop_merge
ok! jump oknoast_19
loc_pop_rewind
status_fail
return(this example keeps going, bestie ✨)
oknoast_19:
loc_pop_discard
return
#
# value Symbol 'Expression'
#
sym_Expression:
# /
# x
# '\('
# (Expression)
# '\)'
# x
# (Factor)
# *
# x
# (MulOp)
# (Factor)
symbol_restore Expression
found! jump found_46
loc_push
ast_push
call choice_44
fail! value_clear
ok! value_reduce Expression
symbol_save Expression
error_nonterminal Expression
ast_pop_rewind
loc_pop_discard
found_46:
ok! ast_value_push
returnokay so bestie, that first label oknoast_19 is literally just wrapping up a rule from the part before this one — it pops the location and returns, that's the whole vibe 💅
then we get to the main character of this chunk: sym_Expression 🎀 and see how those # comment lines right under it are literally the grammar rule written out? like / = ordered choice, x = sequence, * = star/kleene, ? = optional — it's the recipe, and the assembly below is the recipe cooked fr fr ✨
the way that symbol_restore Expression + found! jump found_46 works is giving memoization energy — if we already built this nonterminal, we jump straight to found_46, hit ast_value_push, and bounce 🦋 no re-parsing, obsessed.
and if it isn't cached? we loc_push, ast_push, call choice_44, and then the outcome branches:
- on failure →
value_clearand unwind - on success →
value_reduce Expression,symbol_save Expression,error_nonterminal Expression,ast_pop_rewind,loc_pop_discard🌸
no cap, that's the whole pattern. it repeats for literally every nonterminal in this file and honestly? iconic consistency 💜
now choice_44 is the ordered-choice dispatch — it saves state, tries sequence_27 first, and if that dies it rewinds and tries sequence_40 instead, then finally gives up with status_fail if both flop 😭
choice_44:
# /
# x
# '\('
# (Expression)
# '\)'
# x
# (Factor)
# *
# x
# (MulOp)
# (Factor)
error_clear
ast_push
loc_push
error_push
call sequence_27
error_pop_merge
ok! jump ok_43
ast_pop_rewind
loc_pop_rewind
ast_push
loc_push
error_push
call sequence_40
error_pop_merge
ok! jump ok_43
ast_pop_rewind
loc_pop_rewind
status_fail
return
ok_43:
ast_pop_discard
loc_pop_discard
returnlowkey the ok_43 landing pad is so clean — ast_pop_discard, loc_pop_discard, return, done 🫶
here's sequence_27 — that's the parenthesized branch, '\(' (Expression) '\)' — it literally does test_char "(", calls sym_Expression, then test_char ")" 🧚 and sequence_40 is the other branch: (Factor) * (MulOp) (Factor), so sym_Factor then kleene_37 on repeat 💫
sequence_27:
# x
# '\('
# (Expression)
# '\)'
loc_push
error_clear
error_push
input_next "t ("
ok! test_char "("
error_pop_merge
fail! jump failednoast_29
ast_push
error_push
call sym_Expression
error_pop_merge
fail! jump failed_28
error_push
input_next "t )"
ok! test_char ")"
error_pop_merge
fail! jump failed_28
ast_pop_discard
loc_pop_discard
return
failed_28:
ast_pop_rewind
failednoast_29:
loc_pop_rewind
returnngl the failed_28 / failednoast_29 two-step cleanup is giving parallel-universe energy — one path had an AST pushed and needs ast_pop_rewind, the other never got that far and only needs loc_pop_rewind 🙈 like yes queen, know your unwind depth.
sequence_40:
# x
# (Factor)
# *
# x
# (MulOp)
# (Factor)
ast_push
loc_push
error_clear
error_push
call sym_Factor
error_pop_merge
fail! jump failed_41
error_push
call kleene_37
error_pop_merge
fail! jump failed_41
ast_pop_discard
loc_pop_discard
return
failed_41:
ast_pop_rewind
loc_pop_rewind
returnthen kleene_37 is the star loop — (MulOp) (Factor) zero or more times 🔁 and sequence_34 is a single (MulOp) (Factor) pair. watch the loop: it calls sequence_34, and on failure it jumps to failed_38, which rewinds and — plot twist — returns status_ok, because zero repetitions is still a valid star ✨ and on success it discards the location and jump kleene_37 right back around 💖
kleene_37:
# *
# x
# (MulOp)
# (Factor)
loc_push
error_push
call sequence_34
error_pop_merge
fail! jump failed_38
loc_pop_discard
jump kleene_37
failed_38:
loc_pop_rewind
status_ok
return sequence_34:
# x
# (MulOp)
# (Factor)
ast_push
loc_push
error_clear
error_push
call sym_MulOp
error_pop_merge
fail! jump failed_35
error_push
call sym_Factor
error_pop_merge
fail! jump failed_35
ast_pop_discard
loc_pop_discard
return
failed_35:
ast_pop_rewind
loc_pop_rewind
return
#
# value Symbol 'Factor'
#
sym_Factor:
# x
# (Term)
# *
# x
# (AddOp)
# (Term)
symbol_restore Factor
found! jump found_60
loc_push
ast_push
call sequence_57
fail! value_clear
ok! value_reduce Factor
symbol_save Factor
error_nonterminal Factor
ast_pop_rewind
loc_pop_discard
found_60:
ok! ast_value_push
returnand boom, sym_Factor arrives — same memoized symbol_restore glow-up as Expression, just with found_60 as its landing pad 🎀 it calls sequence_57, and on success does the value_reduce Factor → symbol_save Factor → error_nonterminal Factor → unwind combo 💅
sequence_57 is (Term) * ((AddOp) (Term)), kleene_54 is the star, sequence_51 is one (AddOp) (Term) — exact same shape as the multiplication layer, just with AddOp and Term swapped in 🦋
sequence_57:
# x
# (Term)
# *
# x
# (AddOp)
# (Term)
ast_push
loc_push
error_clear
error_push
call sym_Term
error_pop_merge
fail! jump failed_58
error_push
call kleene_54
error_pop_merge
fail! jump failed_58
ast_pop_discard
loc_pop_discard
return
failed_58:
ast_pop_rewind
loc_pop_rewind
return
kleene_54:
# *
# x
# (AddOp)
# (Term)
loc_push
error_push
call sequence_51
error_pop_merge
fail! jump failed_55
loc_pop_discard
jump kleene_54
failed_55:
loc_pop_rewind
status_ok
return
sequence_51:
# x
# (AddOp)
# (Term)
ast_push
loc_push
error_clear
error_push
call sym_AddOp
error_pop_merge
fail! jump failed_52
error_push
call sym_Term
error_pop_merge
fail! jump failed_52
ast_pop_discard
loc_pop_discard
return
failed_52:
ast_pop_rewind
loc_pop_rewind
return
#
# value Symbol 'MulOp'
#
sym_MulOp:
# /
# '*'
# '/'
symbol_restore MulOp
found! jump found_67
loc_push
call choice_65
fail! value_clear
ok! value_leaf MulOp
symbol_save MulOp
error_nonterminal MulOp
loc_pop_discard
found_67:
ok! ast_value_push
returnok so sym_MulOp is a leaf, bestie — notice it's value_leaf MulOp instead of value_reduce, and there's no ast_push / ast_pop_rewind anywhere in it, because a leaf has literally nothing to recurse into 💀 it's just symbol_restore → choice_65 → memoize → found_67 → ast_value_push → bye 💖
and choice_65 is the tiniest ordered choice imaginable: try test_char "*", else rewind and try test_char "/", else status_fail 🙈 its success pad is oknoast_64, which is the no-AST variant — loc_pop_discard and return, no ast_pop_discard needed because this choice never pushed an AST 🧚
choice_65:
# /
# '*'
# '/'
error_clear
loc_push
error_push
input_next "t *"
ok! test_char "*"
error_pop_merge
ok! jump oknoast_64
loc_pop_rewind
loc_push
error_push
input_next "t /"
ok! test_char "/"
error_pop_merge
ok! jump oknoast_64
loc_pop_rewind
status_fail
return
oknoast_64:
loc_pop_discard
return
#
# value Symbol 'Number'
#
sym_Number:
# x
# ?
# (Sign)
# +
# (Digit)
symbol_restore Number
found! jump found_80
loc_push
ast_push
call sequence_77
fail! value_clear
ok! value_reduce Number
symbol_save Number
error_nonterminal Number
ast_pop_rewind
loc_pop_discard
found_80:
ok! ast_value_push
returnfinally for this stretch, sym_Number 👑 — the rule is ? (Sign) followed by + (Digit), so an optional sign and then one-or-more digits. same memoize-or-build skeleton, landing on found_80, and sequence_77 is the assembly: optional_70 for the sign, then poskleene_73 for the positive kleene (that's the +) 🍓
sequence_77:
# x
# ?
# (Sign)
# +
# (Digit)
ast_push
loc_push
error_clear
error_push
call optional_70
error_pop_merge
fail! jump failed_78
error_push
call poskleene_73
error_pop_merge
fail! jump failed_78
ast_pop_discard
loc_pop_discard
return
failed_78:
ast_pop_rewind
loc_pop_rewind
returnand that's exactly where this part runs out of code — optional_70 and poskleene_73 are the next girls up, so stay tuned bestie 💜✨
optional_70:
# ?
# (Sign)
loc_push
error_push
call sym_Sign
error_pop_merge
fail! loc_pop_rewind
ok! loc_pop_discard
status_ok
return
poskleene_73:
# +
# (Digit)
loc_push
call sym_Digit
fail! jump failed_74
loop_75:
loc_pop_discard
loc_push
error_push
call sym_Digit
error_pop_merge
ok! jump loop_75
status_ok
failed_74:
loc_pop_rewind
return
#
# value Symbol 'Sign'
#
sym_Sign:
# /
# '-'
# '+'
symbol_restore Sign
found! jump found_86
loc_push
call choice_5
fail! value_clear
ok! value_leaf Sign
symbol_save Sign
error_nonterminal Sign
loc_pop_discard
found_86:
ok! ast_value_push
return
#
# value Symbol 'Term'
#
sym_Term:
# (Number)
symbol_restore Term
found! jump found_89
loc_push
ast_push
call sym_Number
fail! value_clear
ok! value_reduce Term
symbol_save Term
error_nonterminal Term
ast_pop_rewind
loc_pop_discard
found_89:
ok! ast_value_push
return
#
#✨ PEG SERIALIZATION FORMAT ✨
okay bestie, new section, new vibe 💖 This is where we spill the tea on the exact format that the Parser Tools use to serialize Parsing Expression Grammars — like, turning them into immutable values so they can be shipped around, compared, whatever. ✨
And there's a whole two-tier situation going on, so pay attention 🫶: we distinguish between regular and canonical serializations. A PEG can have more than one regular serialization, but exactly one of them is canonical. Periodt. 💅
💾 regular serialization
- The serialization of any PEG is a nested Tcl dictionary. 🌸
- This dictionary holds a single key,
pt::grammar::peg, and its value. That value holds the contents of the grammar. 👑 - The contents of the grammar are a Tcl dictionary holding the set of nonterminal symbols and the starting expression. The relevant keys and their values are:
rules— The value is a Tcl dictionary whose keys are the names of the nonterminal symbols known to the grammar. 🎀- Each nonterminal symbol may occur only once.
- The empty string is not a legal nonterminal symbol. (not me trying to name a rule
""💀) - The value for each symbol is a Tcl dictionary itself. The relevant keys and their values in this dictionary are:
is— The value is the serialization of the parsing expression describing the symbols sentennial structure, as specified in the section PE serialization format. ✨mode— The value can be one of three values specifying how a parser should handle the semantic value produced by the symbol. 🦋value— The semantic value of the nonterminal symbol is an abstract syntax tree consisting of a single node node for the nonterminal itself, which has the ASTs of the symbol's right hand side as its children. 🌈leaf— The semantic value of the nonterminal symbol is an abstract syntax tree consisting of a single node node for the nonterminal, without any children. Any ASTs generated by the symbol's right hand side are discarded. 🙈void— The nonterminal has no semantic value. Any ASTs generated by the symbol's right hand side are discarded (as well). 💀
start— The value is the serialization of the start parsing expression of the grammar, as specified in the section PE serialization format. ⭐
- The terminal symbols of the grammar are specified implicitly as the set of all terminal symbols used in the start expression and on the RHS of the grammar rules. 🧚
👑 canonical serialization
The canonical serialization of a grammar has the format as specified in the previous item, and then additionally satisfies the constraints below — which is what makes it unique among all the possible serializations of this grammar. One grammar, one canonical form. Main character energy only. 💅
- The keys found in all the nested Tcl dictionaries are sorted in ascending dictionary order, as generated by Tcl's builtin command
lsort -increasing -dict. 🎀 - The string representation of the value is the canonical representation of a Tcl dictionary. I.e. it does not contain superfluous whitespace. No extra crumbs, we keep it clean. ✨
🍓 EXAMPLE
Say we're working with the following PEG for simple mathematical expressions 👇
PEG calculator (Expression)
Digit <- '0'/'1'/'2'/'3'/'4'/'5'/'6'/'7'/'8'/'9' ;
Sign <- '-' / '+' ;
Number <- Sign? Digit+ ;
Expression <- Term (AddOp Term)* ;
MulOp <- '*' / '/' ;
Term <- Factor (MulOp Factor)* ;
AddOp <- '+'/'-' ;
Factor <- '(' Expression ')' / Number ;
END;Then its canonical serialization (except for whitespace) is this absolute serve 💖👇
pt::grammar::peg {
rules {
AddOp {is {/ {t -} {t +}} mode value}
Digit {is {/ {t 0} {t 1} {t 2} {t 3} {t 4} {t 5} {t 6} {t 7} {t 8} {t 9}} mode value}
Expression {is {x {n Term} {* {x {n AddOp} {n Term}}}} mode value}
Factor {is {/ {x {t (} {n Expression} {t )}} {n Number}} mode value}
MulOp {is {/ {t *} {t /}} mode value}
Number {is {x {? {n Sign}} {+ {n Digit}}} mode value}
Sign {is {/ {t -} {t +}} mode value}
Term {is {x {n Factor} {* {x {n MulOp} {n Factor}}}} mode value}
}
start {n Expression}
}So here's the tea ☕: this is the format the Parser Tools use to serialize Parsing Expressions as immutable values — like, for transport, comparison, and all that jazz. 💖
We distinguish between regular and canonical serializations. A parsing expression can have more than one regular serialization, but only exactly one of them will ever be canonical. No cap. 💅
✨ Regular serialization ✨
🧬 Atomic Parsing Expressions 🧬
epsilon— this string is an atomic parsing expression. It matches the empty string. Periodt. 🫧dot— also an atomic parsing expression. It matches any character. Literally any. 🌈alnum— atomic parsing expression, matches any Unicode alphabet or digit character. This is a custom extension of PEs based on Tcl's builtin commandstring is. Iykyk. 💅alpha— matches any Unicode alphabet character. Also a custom extension based on Tcl'sstring is. 👑ascii— matches any Unicode character belowU0080. Custom extension based onstring is. 💻control— matches any Unicode control character. Custom extension based onstring is. 🎮digit— matches any Unicode digit character. And yes, that includes characters outside the[0..9]range, bestie. 🤯 Custom extension based onstring is.graph— matches any Unicode printing character, except for space. Custom extension based onstring is. 📊lower— matches any Unicode lower-case alphabet character. Custom extension based onstring is. 🔡print— matches any Unicode printing character, including space. Custom extension based onstring is. 🖨️punct— matches any Unicode punctuation character. Custom extension based onstring is. ‼️space— matches any Unicode space character. Custom extension based onstring is. 🌌upper— matches any Unicode upper-case alphabet character. Custom extension based onstring is. 🔠wordchar— matches any Unicode word character. That's any alphanumeric character (seealnum) plus any connector punctuation characters, like underscore. Custom extension based onstring is. 📝xdigit— matches any hexadecimal digit character. Custom extension based onstring is. 🔢ddigit— matches any decimal digit character. This one is a custom extension based on Tcl's builtin commandregexp. 👀- The expression
[list t x]is an atomic parsing expression. It matches the terminal stringx. 🎯 - The expression
[list n A]is an atomic parsing expression. It matches the nonterminalA. 🏷️
🧩 Combined Parsing Expressions 🧩
- For parsing expressions
e1,e2, ..., the result of[list / e1 e2 ... ]is a parsing expression too. This is the ordered choice, aka prioritized choice. Choose your fighter. 🥊 - For parsing expressions
e1,e2, ..., the result of[list x e1 e2 ... ]is a parsing expression as well. This is the sequence. One after the other. ➡️ - For a parsing expression
e, the result of[list * e]is a parsing expression as well. This is the kleene closure, describing zero or more repetitions. Star power. ⭐ - For a parsing expression
e, the result of[list + e]is a parsing expression as well. This is the positive kleene closure, describing one or more repetitions. Plus sign energy. ➕ - For a parsing expression
e, the result of[list & e]is a parsing expression as well. This is the and lookahead predicate. Peek ahead. 🔮 - For a parsing expression
e, the result of[list ! e]is a parsing expression as well. This is the not lookahead predicate. Nope, not today. 🚫 - For a parsing expression
e, the result of[list ? e]is a parsing expression as well. This is the optional input. Maybe, maybe not. 🤷
👑 Canonical serialization 👑
The canonical serialization of a parsing expression uses the format from the previous item, but then it also has to satisfy the constraints below. These make it unique among all possible serializations of that parsing expression. So it's the one true queen. 👑
- The string representation of the value is the canonical representation of a pure Tcl list. I.e., it does not contain superfluous whitespace. No extra spaces, bestie. ✂️
- Terminals are not encoded as ranges (where the start and end of the range are identical). Keep it simple. 🎀
🌟 EXAMPLE 🌟
Assuming the parsing expression shown on the right-hand side of the rule
Expression <- Term (AddOp Term)*then its canonical serialization (except for whitespace) is
{x {n Term} {* {x {n AddOp} {n Term}}}}🐞 BUGS, IDEAS, FEEDBACK 🐞
This document, and the package it describes, will undoubtedly contain bugs and other problems. I know, shocking. 😭 Please report such in the category pt of the Tcllib Trackers at http://core.tcl.tk/tcllib/reportlist. Also, if you have ideas for enhancements for either the package and/or the documentation, please report those too. We love a glow-up. ✨
When proposing code changes, please provide unified diffs, i.e., the output of diff -u. That's the move. 💅
Also note: attachments are strongly preferred over inlined patches. You can attach files by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar. Easy peasy. 🍋
🔑 KEYWORDS 🔑
EBNFLL(k)PARAMPEGTDPLcontext-free languagesconversionexpressionformat conversiongrammarmatchingparserparsing expressionparsing expression grammarpush down automatonrecursive descentserializationstatetop-down parsing languagestransducer
📂 CATEGORY 📂
Parsing and Grammars. That's the category. Slay. 💅
© COPYRIGHT ©
Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>. Respect the OG. 🙌
And that's the whole vibe. This page is from tcllib 1.1, for pt::peg::to::param(n). Stay slay, bestie. 💖✨
📦 where this page comes from
- fedora 43: tcllib 2.0-3.fc43 · TCL
- fedora 44: tcllib 2.0-4.fc44 · TCL
- nixos 26.05: tcllib 2.0
- nixpkgs unstable: tcllib 2.0
- Copyright (c) 2009 Andreas Kupries <andreas_kupries@users\&.sourceforge\&.net>
- 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms