grammar::me::util(3tcl)

✨ NAME ✨

grammar::me::util — AST utilities 💖 (yes bestie, it's giving "little helper package that does the tree-to-value glow-up")

---

🌸 SYNOPSIS 🌸

package require Tcl 8.5 9

package require grammar::me::util ?0.2?

::grammar::me::util::ast2tree ast tree ?root?

::grammar::me::util::ast2etree ast mcmd tree ?root?

mcmd lc location

mcmd tok from ?to?

::grammar::me::util::tree2ast tree ?root?

---

🦋 DESCRIPTION 🦋

okay so this package is literally the friend group of utility commands that lets you convert between the different representations of abstract syntax trees — the ones spelled out over in the grammar::me_ast document. no cap, that's the whole vibe. 🎀

• ::grammar::me::util::ast2tree ast tree ?root? — this one converts an ast from value representation to object representation. every single node in the ast gets converted into a node of this tree, and the root of the AST becomes a child of the node root. if you don't explicitly hand over that node, the root of the tree is used instead, default behaviour slay. 🫶 and listen: existing content of tree is not touched — not removed, not changed, nothing — with the one exception of the specified root node, which will gain a new child. so yeah, it's additive, she's respectful. ✨
• ::grammar::me::util::ast2etree ast mcmd tree ?root? — basically ::grammar::me::util::ast2tree's sibling, same energy, except the result comes out in the extended object representation of the input AST. and where does the extended info come from? the command prefix mcmd. 👑 she has to understand two methods, lc and tok, with the semantics specified right below, so let's get into it:
  • mcmd lc location — takes the location of a token, given as an offset in the input stream, and returns a 2-element list holding the associated line number and column index, in that order. two numbers, one list, iconic. 📍
  • mcmd tok from ?to? — takes one or two locations, from and to, as offsets in the input stream, and returns a Tcl list containing the specified part of the input stream. both locations are inclusive, so don't come for me about off-by-ones, she's inclusive on purpose. 💅 if to isn't specified it defaults to the value of from — so you get exactly one. each element of the returned list is itself a list containing the token, its associated lexeme, the line number, and column index, in this order. four things, that order, periodt. 🍓

and for the record, both the ensemble command ::grammar::me::tcl (provided by the package grammar::me::tcl) and the objects command created by the package ::grammar::me::cpu fit the above specification. so you've got options, bestie. 🌈

• ::grammar::me::util::tree2ast tree ?root? — the reverse direction, the glow-down if you will. this one converts an ast in (extended) object representation into a value and returns it. if you specify a root node, the AST gets generated from that node downward. otherwise the root of the tree object is used as the starting point. 🌟

---

💀 BUGS, IDEAS, FEEDBACK 💀

ngl, this document, and the package it describes, will undoubtedly contain bugs and other problems. 😭 please report such in the category grammar_me of the Tcllib Trackers at [http://core.tcl.tk/tcllib/reportlist]. and please also report any ideas for enhancements you may have for either the package and/or the documentation — we want all of it, fr fr. 🙈

when proposing code changes, please provide unified diffs, i.e the output of diff -u. (yes, exactly that, don't freestyle it.)

also note, attachments are strongly preferred over inlined patches. 📎 attachments can be made 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. iykyk.

---

⭐ KEYWORDS ⭐

abstract syntax tree, syntax tree, tree

---

👑 CATEGORY 👑

Grammars and finite automata

---

💜 COPYRIGHT 💜

Copyright (c) 2005 Andreas Kupries <andreas_kupries@users.sourceforge.net>

---

and that's the whole page, bestie — brought to you by tcllib, version 0.2, living its best life as grammar::me::util(3tcl). go build some trees, you've got this 🧚✨🎀