Worked on #3 where I believe the regexp part is now complete but it needs testing

experiments/config1.mjs

@@ -1,4 +1,4 @@
-import { Schema, Field_Configuration  } from '@efforting.tech/data/field-configuration';
+import { Schema, Field_Configuration  } from '@efforting.tech/schema/field-configuration';
 
 
 function mandatory_anything(value) {

experiments/config2.mjs

@@ -1,4 +1,4 @@
-import * as F from '@efforting.tech/data/field-configuration-factories';
+import * as F from '@efforting.tech/schema/field-configuration-factories';
 
 const s = new F.Schema({
 	foo: F.value(123, 'The value'),

experiments/feature-stub.mjs

@@ -0,0 +1,30 @@
+
+import { Stub } from '@efforting.tech/feature/stub';
+/*
+
+export function Stub(meta, name, description, module_name, function_name) {
+	return function stub() {
+		throw new Error(`The feature "${name}" of "${meta.url}" is not enabled. Enable it by calling "${function_name}(${this.name})" imported from "${module_name}"`);	//TODO - specific error
+	}
+}
+
+*/
+
+class Thing {
+
+	static from_stuff = Stub(import.meta, 'stuff-loader', 'Creates Thing from stuff', '@efforting.tech/stuff/loader', 'enable_stuff_loader');
+
+}
+
+Thing.from_stuff()
+
+/*
+
+Error: The feature "stuff-loader" of "file:///srv/Projekt/efforting.tech/nodejs.esm-library/experiments/generic-parser-2.mjs" is not enabled. Enable it by calling "enable_stuff_loader(Thing)" imported from "@efforting.tech/stuff/loader"
+    at Thing.stub [as from_stuff] (file:///srv/Projekt/efforting.tech/nodejs.esm-library/build/packages/feature/stub.mjs:4:9)
+    at file:///srv/Projekt/efforting.tech/nodejs.esm-library/experiments/generic-parser-2.mjs:10:7
+    at ModuleJob.run (node:internal/modules/esm/module_job:430:25)
+    at async node:internal/modules/esm/loader:639:26
+    at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
+
+*/

experiments/generic-parser-1.mjs

@@ -0,0 +1,40 @@
+import { RegExp_Tokenizer } from '@efforting.tech/parsing/regexp-dispatch';
+import { RegExp_Token_Parsing_Rule, Parser } from '@efforting.tech/parsing/generic-parsing';
+
+import { inspect } from 'node:util';
+
+const text = 'Hello World (how are you (doing)) I may ask';
+
+const rt = new RegExp_Tokenizer();
+rt.add_rules(new RegExp_Token_Parsing_Rule(/\w+/, (tokenizer, match) => tokenizer.push_token(match.value), 'word'));
+rt.add_rules(new RegExp_Token_Parsing_Rule(/\s+/, null, 'space'));
+rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape('('), (tokenizer, match) => tokenizer.enter_sub_tokenizer(undefined, (tokenizer, value) => tokenizer.push_token({kind: 'sub expression', value}) ), 'lpar'));
+rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape(')'), (tokenizer, match) => tokenizer.leave_sub_tokenizer(), 'rpar'));
+
+const p = new Parser(text, { tokenizer: rt });
+
+console.log(inspect(p.parse((tokenizer, value) => tokenizer.replace_value({kind: 'parsing result', value})), { colors: true, depth: null }));
+
+/*
+
+{
+  kind: 'parsing result',
+  value: [
+    'Hello',
+    'World',
+    {
+      kind: 'sub expression',
+      value: [
+        'how',
+        'are',
+        'you',
+        { kind: 'sub expression', value: [ 'doing' ] }
+      ]
+    },
+    'I',
+    'may',
+    'ask'
+  ]
+}
+
+*/

experiments/generic-parser-2.mjs

@@ -0,0 +1,146 @@
+import { Row_Based_Table } from '@efforting.tech/table';
+import { load_raster_table } from '@efforting.tech/table/raster-table';
+import { RegExp_Tokenizer } from '@efforting.tech/parsing/regexp-dispatch';
+import { RegExp_Token_Parsing_Rule, Parser } from '@efforting.tech/parsing/generic-parsing';
+
+
+function load_table(raster) {
+	const table = load_raster_table(raster, Row_Based_Table);
+	table.replace_all_cells(({cell}) => cell.trim());
+	return table;
+}
+
+const logic_ops = load_table(`
+
+	name		symbol
+	----		------
+	AND			∧
+	OR			∨
+	XOR			⊕
+	NAND		↑
+	NOR			↓
+	XNOR		⊙
+	IMPLIES		→
+	IFF			↔
+	NOT			¬
+
+`);
+
+const generic_ops = load_table(`
+
+	name		symbol
+	----		------
+	PLUS		+
+	HYPHEN		-
+	DOT			·
+	ASTERISK	*
+	CROSS		×
+	SLASH		/
+	CARET		^
+	UNDERSCORE	_
+	PERCENT		%
+
+`);
+
+const punctuation = load_table(`
+
+	name		symbol
+	----		------
+	COMMA		,
+	SEMI_COLON	;
+	COLON		:
+	PERIOD		.
+
+`);
+
+const grouping = load_table(`
+
+	name					left	right
+	----					----	-----
+	PARENTESIS				(		)
+	SQUARE_BRACKET			[		]
+	CURLY_BRACE				{		}
+	ANGLE_BRACKET			⟨		⟩
+	DOUBLE_ARROW_BRACKET	«		»
+
+`);
+
+const greek_chars = load_table(`
+
+	name		lower	upper
+	----		-----	-----
+	ALPHA		α		Α
+	BETA		β		Β
+	GAMMA		γ		Γ
+	DELTA		δ		Δ
+	EPSILON		ε		Ε
+	ZETA		ζ		Ζ
+	ETA			η		Η
+	THETA		θ		Θ
+	IOTA		ι		Ι
+	KAPPA		κ		Κ
+	LAMBDA		λ		Λ
+	MU			μ		Μ
+	NU			ν		Ν
+	XI			ξ		Ξ
+	OMICRON		ο		Ο
+	PI			π		Π
+	RHO			ρ		Ρ
+	SIGMA		σ		Σ
+	TAU			τ		Τ
+	UPSILON		υ		Υ
+	PHI			φ		Φ
+	CHI			χ		Χ
+	PSI			ψ		Ψ
+	OMEGA		ω		Ω
+
+`);
+
+
+
+
+
+const rt = new RegExp_Tokenizer();
+
+for (const { name, left, right } of grouping.iter_objects()) {
+	rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape(left),
+		(tokenizer, ingress_match) => tokenizer.enter_sub_tokenizer(undefined,
+			(tokenizer, value, egress_match) => tokenizer.push_token(
+				{kind: 'EXPR', name, value, ingress_match, egress_match}
+			)
+		), `LEFT_${name}`
+	));
+
+	rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape(right),
+		(tokenizer, match) => tokenizer.leave_sub_tokenizer(match), `RIGHT_${name}`)
+	);
+}
+
+
+for (const table of [logic_ops, generic_ops, punctuation]) {
+	for (const { name, symbol } of table.iter_objects()) {
+		rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape(symbol),
+			(tokenizer, match) => tokenizer.push_token({ kind: 'TOKEN', match }), name)
+		);
+	}
+}
+
+for (const { name, lower, upper } of greek_chars.iter_objects()) {
+	rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape(lower),
+		(tokenizer, match) => tokenizer.push_token({ kind: 'TOKEN', match }), `LOWER_${name}`)
+	);
+	rt.add_rules(new RegExp_Token_Parsing_Rule(RegExp.escape(upper),
+		(tokenizer, match) => tokenizer.push_token({ kind: 'TOKEN', match }), `UPPER_${name}`)
+	);
+}
+
+rt.add_rules(new RegExp_Token_Parsing_Rule(/\w+/, (tokenizer, match) => tokenizer.push_token({ kind: 'TOKEN', match }), 'WORD'));
+rt.add_rules(new RegExp_Token_Parsing_Rule(/\s+/, null, 'WHITESPACE'));
+
+
+const text = 'Hello World (how are you (doing)) I may ask';
+const p = new Parser(text, { tokenizer: rt });
+
+//console.log(rt.rules.at(-3));
+
+console.log(p.parse())

experiments/package.json

@@ -1,4 +1,7 @@
 {
+  "name": "@efforting.tech/experiments",
+  "version": "0.0.1",
+  "private": true,
   "devDependencies": {
     "tree-sitter": "^0.25.0",
     "tree-sitter-javascript": "^0.25.0"

experiments/reduction-scanner-1.mjs

@@ -1,14 +1,109 @@
 import { Reduction_Scanner, Reduction_Settings } from  '@efforting.tech/rule-processing/reduction-scanner';
-//import { Sub_Sequence_Rule } from  '@efforting.tech/rule-processing/rules';
+import * as R from  '@efforting.tech/rule-processing/rules';
+
+import { inspect } from 'node:util';
+
+/*
+Here's what needs addressing:
+
+**`perform_reduction` refactor**
+- Remove the `start_index` loop — scanning is the condition's responsibility
+- RULE_MAJOR: iterate rules, call `rule.match(sequence, context)`, apply first that returns a match
+- POSITION_MAJOR: collect matches from all rules, apply the one with lowest `start_index` in result
+
+**`Sequence_Condition.match` implementation**
+- Iterate positions internally
+- Return match result with `start_index`, `end_index`, captures
+- Return null if no match found anywhere
+
+**Rule interface**
+- `rule.match(sequence, context)` → match result or null
+- `rule.action(scanner, sequence, match)` → performs the transformation
+- Decide: forwarding getters, bind in constructor, or scanner calls `rule.condition.match` directly
+
+**Match result shape**
+- `{ rule, sequence, start_index, end_index, captures, ...extra_info }`
+- `captures` lazily evaluated via getter
+
+**Normalization**
+- Decide when rules get normalized/compiled (construction, first transform, explicit `prepare()`)
+- Normalize bare functions to condition objects at that point
+
+**`context` shape**
+- What does the scanner inject into context beyond `start_index`/`end_index`?
+- How does `extra_info` from resolver flow through to condition match?
+*/
 
 
-const rss = Reduction_Settings.load();
 
+class Rule {	//NOTE: This is somewhat of a place holder because we may want to declare specific transformations later rather than always having an opaque handler function
+	constructor(condition, handler) {
+		Object.assign(this, { condition, handler });
+	}
+
+	get match() {
+		return this.condition.match.bind(this.condition);
+	}
+
+	get action() {
+		return this.handler;
+	}
+
+}
+
+
+
+
+const N = new R.Predicate((i) => typeof i === 'number' || i.type == 'BINOP' );
+const ASTERISK = new R.Strict_Equality('*');
+const PLUS = new R.Strict_Equality('+');
+
+
+const rss = Reduction_Settings.load({
+	// Switching this on or off affects whether add comes before mul or not
+	//reduction_order: 'POSITION_MAJOR',
+});
 const rs = new Reduction_Scanner(rss);
 
-rss.rules.push();
 
+rss.rules.push(
+	new Rule(
+		new R.Sequence_Condition([N, ASTERISK, N]),
+		(rs, sequence, match) => {
+			const MS = match.match_start;
+			const ME = match.match_end;
+			sequence.splice(MS, ME - MS + 1, { type: 'BINOP', op: 'MUL', operands: [sequence[MS], sequence[ME]]});
+		}
+	),
+
+	new Rule(
+		new R.Sequence_Condition([N, PLUS, N]),
+		(rs, sequence, match) => {
+			const MS = match.match_start;
+			const ME = match.match_end;
+			sequence.splice(MS, ME - MS + 1, { type: 'BINOP', op: 'ADD', operands: [sequence[MS], sequence[ME]]});
+		},
+	),
+
+);
 
 const arr = [10, '+', 20, '*', 30];
-console.log(rs.perform_reduction(arr));
-console.log(arr);
+console.log(inspect(rs.transform(arr), { colors: true, depth: null }));
+
+/* OUTPUT
+
+[
+  {
+    type: 'BINOP',
+    op: 'ADD',
+    operands: [ 10, { type: 'BINOP', op: 'MUL', operands: [ 20, 30 ] } ]
+  }
+]
+
+
+*/
+
+
+// These are for testing conditions without reduction
+// const sc = new R.Sequence_Condition([N, PLUS, N]);
+// console.log(sc.match([10, '+', 20, '*', 30]));

experiments/reduction-scanner-2.mjs

@@ -0,0 +1,76 @@
+import { Reduction_Scanner, Reduction_Settings } from  '@efforting.tech/rule-processing/reduction-scanner';
+import * as R from  '@efforting.tech/rule-processing/rules';
+
+import { inspect } from 'node:util';
+
+
+
+class Rule {	//NOTE: This is somewhat of a place holder because we may want to declare specific transformations later rather than always having an opaque handler function
+	constructor(condition, handler) {
+		Object.assign(this, { condition, handler });
+	}
+
+	get match() {
+		return this.condition.match.bind(this.condition);
+	}
+
+	get action() {
+		return this.handler;
+	}
+
+}
+
+
+
+function sequence_rule(sequence, transform_fn) {
+	return new Rule(
+		new R.Sequence_Condition(sequence),
+		(rs, sequence, match) => {
+			const MS = match.match_start;
+			const ME = match.match_end;
+			sequence.splice(MS, ME - MS + 1, transform_fn(...sequence.slice(MS, ME + 1)));
+		}
+	);
+}
+
+
+const N = new R.Predicate((i) => typeof i === 'number' || i.type == 'BINOP' );
+const ASTERISK = new R.Strict_Equality('*');
+const PLUS = new R.Strict_Equality('+');
+const HAT = new R.Strict_Equality('^');
+
+
+const rss = Reduction_Settings.load({
+	// Switching this on or off affects whether add comes before mul or not
+	//reduction_order: 'POSITION_MAJOR',
+});
+
+const rs = new Reduction_Scanner(rss);
+
+rss.rules.push(
+
+	sequence_rule([N, HAT, N], 		(left, op, right) => ({ type: 'BINOP', op: 'HAT', operands: [left, right]})),
+	sequence_rule([N, ASTERISK, N], (left, op, right) => ({ type: 'BINOP', op: 'ASTERISK', operands: [left, right]})),
+	sequence_rule([N, PLUS, N], 	(left, op, right) => ({ type: 'BINOP', op: 'PLUS', operands: [left, right]})),
+
+);
+
+const arr = [10, '^', 5, '+', 20, '*', 30];
+console.log(inspect(rs.transform(arr), { colors: true, depth: null }));
+
+/* OUTPUT
+
+
+[
+  {
+    type: 'BINOP',
+    op: 'PLUS',
+    operands: [
+      { type: 'BINOP', op: 'HAT', operands: [ 10, 5 ] },
+      { type: 'BINOP', op: 'ASTERISK', operands: [ 20, 30 ] }
+    ]
+  }
+]
+
+
+*/

experiments/reduction-scanner-3.mjs

@@ -0,0 +1,157 @@
+import { Reduction_Scanner, Reduction_Settings } from  '@efforting.tech/rule-processing/reduction-scanner';
+import * as R from  '@efforting.tech/rule-processing/rules';
+
+import { inspect } from 'node:util';
+
+
+class Rule_Match {
+	constructor(rule, match) {
+		Object.assign(this, { rule, match });
+	}
+
+	get action() {
+		return this.rule.handler;
+	}
+
+
+}
+
+
+class Rule {	//NOTE: This is somewhat of a place holder because we may want to declare specific transformations later rather than always having an opaque handler function
+	constructor(condition, handler) {
+		Object.assign(this, { condition, handler });
+	}
+
+	match(...args) {
+		const match = this.condition.match(...args);
+		if (match) {
+			return new Rule_Match(this, match);
+		}
+	}
+
+
+}
+
+class Sub_Scan_Rule_Match {
+	constructor(rule, sub_scan_candidate) {
+		Object.assign(this, { rule, sub_scan_candidate });
+	}
+
+	get action() {
+		return this.sub_scan_candidate.match.action;
+	}
+
+	get match() {
+		return this.sub_scan_candidate.match.match;
+	}
+
+}
+
+class Sub_Scan_Rule {
+	constructor(sub_system) {
+		Object.assign(this, { sub_system });
+	}
+
+	match(...args) {
+		const candidate = this.sub_system.find_reduction_candidate(...args);
+		if (candidate) {
+			return new Sub_Scan_Rule_Match(this, candidate)
+		}
+	}
+
+
+}
+
+
+
+function sequence_rule(sequence, transform_fn) {
+	return new Rule(
+		new R.Sequence_Condition(sequence),
+		({sequence, match}) => {
+			const MS = match.match_start;
+			const ME = match.match_end;
+			sequence.splice(MS, ME - MS + 1, transform_fn(...sequence.slice(MS, ME + 1)));
+		}
+	);
+}
+
+
+
+const N = new R.Predicate((i) => typeof i === 'number' || i.type == 'BINOP' );
+
+const CARET = new R.Strict_Equality('^');
+const CARON = new R.Strict_Equality('ˇ');
+
+const ASTERISK = new R.Strict_Equality('*');
+const SLASH = new R.Strict_Equality('/');
+
+const PLUS = new R.Strict_Equality('+');
+const MINUS = new R.Strict_Equality('-');
+
+// These are the outer settings
+const rss = Reduction_Settings.load();
+
+// These are the inner settings
+const rss_inner = Reduction_Settings.load({
+	reduction_order: 'POSITION_MAJOR',
+});
+
+const rs = new Reduction_Scanner(rss);
+
+// Local factory for sub system
+function sub_system(...rules) {
+	const sub_settings = { ...rss_inner, rules };
+	const scanner = new Reduction_Scanner(sub_settings);
+	return new Sub_Scan_Rule(scanner);
+}
+
+
+
+
+rss.rules.push(
+	sub_system(
+		sequence_rule([N, CARET, N], 		(left, op, right) => ({ type: 'BINOP', op: 'CARET', operands: [left, right]})),
+		sequence_rule([N, CARON, N], 		(left, op, right) => ({ type: 'BINOP', op: 'CARON', operands: [left, right]})),
+	),
+
+	sub_system(
+		sequence_rule([N, ASTERISK, N], (left, op, right) => ({ type: 'BINOP', op: 'ASTERISK', operands: [left, right]})),
+		sequence_rule([N, SLASH, N], (left, op, right) => ({ type: 'BINOP', op: 'SLASH', operands: [left, right]})),
+	),
+
+	sub_system(
+		sequence_rule([N, PLUS, N], 	(left, op, right) => ({ type: 'BINOP', op: 'PLUS', operands: [left, right]})),
+		sequence_rule([N, MINUS, N], 	(left, op, right) => ({ type: 'BINOP', op: 'MINUS', operands: [left, right]})),
+	),
+);
+
+
+const arr = [5, '-', 10, '^', 5, 'ˇ', 2, '+', 20, '*', 30];
+console.log(inspect(rs.transform(arr), { colors: true, depth: null }));
+
+
+/*
+
+[
+  {
+    type: 'BINOP',
+    op: 'MINUS',
+    operands: [
+      5,
+      {
+        type: 'BINOP',
+        op: 'PLUS',
+        operands: [
+          {
+            type: 'BINOP',
+            op: 'CARON',
+            operands: [ { type: 'BINOP', op: 'CARET', operands: [ 10, 5 ] }, 2 ]
+          },
+          { type: 'BINOP', op: 'ASTERISK', operands: [ 20, 30 ] }
+        ]
+      }
+    ]
+  }
+]
+
+*/

experiments/regexp-tokenizer.mjs

@@ -12,4 +12,15 @@ rt.set_default_identifier('random stuff');
 
 for (const m of rt.iter_matches('#Hello World!')) {
 	console.log({class: m.constructor.name, identifier: m.identifier, value: m.value, captured: m.captured });
-};
+};
+
+
+console.log('--=| Slicing |=--')
+
+for (const m of rt.iter_matches('#Hello World!', 3, -3)) {
+	//console.log(m, m.pending_index)
+	console.log({class: m.constructor.name, identifier: m.identifier, value: m.value, captured: m.captured });
+
+
+};
+

experiments/table-1.mjs

@@ -0,0 +1,23 @@
+import { Row_Based_Table } from '@efforting.tech/table'
+
+
+const t = new Row_Based_Table({ column_names: 'SKU, Quantity, Price' });
+
+//console.log(t.column_names_lut);	/* { SKU: 0, Quantity: 1, Price: 2 } */
+
+t.push_rows(
+	['VOLVO-1', 3, 120_000],
+	['VOLVO-2', 4, 140_000],
+)
+
+const [A] = t.read_rows(0);
+const [B] = t.snapshot_rows(1);
+
+console.log(A.value);
+console.log(B.value);
+A.update({Quantity: 5});
+console.log(A.value);
+
+for (const r of t) {
+	console.log(r.object);
+}

experiments/table-2.mjs

@@ -0,0 +1,34 @@
+import { Row_Based_Table } from '@efforting.tech/table';
+import { load_raster_table } from '@efforting.tech/table/raster-table';
+
+
+const t = load_raster_table(`
+
+	SKU		Quantity		Price
+	---		--------		-----
+	V-1		2				120_000
+	V-2		3				140_000
+
+`, Row_Based_Table);
+
+
+// { row_name, column_name, row_index, column_index, row, cell }
+t.replace_all_cells(
+	({column_name, cell}) => {
+		const translation = {
+			SKU: (s) => s.trim(),
+			Quantity: parseInt,
+			Price: (p) => parseFloat(p.replace(/_/g, '')),
+		}[column_name];
+		return translation ? translation(cell) : cell;
+	}
+);
+
+for (const r of t) {
+	console.log(r.object);
+}
+
+/*
+{ SKU: 'V-1', Quantity: 2, Price: 120000 }
+{ SKU: 'V-2', Quantity: 3, Price: 140000 }
+*/

package-manifest.yaml

@@ -1,3 +1,4 @@
+# TODO: Add a way to help making sure we keep internal-dependencies up to date
 scope: '@efforting.tech'
 registry: 'https://npm.efforting.tech/'
 version: 0.2.9
@@ -25,6 +26,24 @@ packages:
     path: source/data
     documentation: documentation/data
     description: Data management
+    internal-dependencies:
+      - schema
+
+  table:
+    path: source/table
+    description: Table management
+    internal-dependencies:
+      - schema
+      - text
+
+  feature:
+    path: source/feature
+    description: Feature management
+
+  schema:
+    path: source/schema
+    #documentation: documentation/schema
+    description: Schema system
     internal-dependencies:
       - errors
 

package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "@efforting.tech/experiments": "file:experiments"
+  }
+}

planning/math-subsystem.md

@@ -0,0 +1,79 @@
+# Mathematical Expression Subsystem
+
+> [!NOTE]
+> This document is written by Claude by Anthropic using Sonnet 4.6 and has yet to be vetted by Mikael Lövqvist
+
+## Overview
+
+A math-like expression language built on top of the reduction scanner, supporting
+operator notation, matrix literals, subscripts, superscripts, and symbolic operators.
+
+## Operator Notation
+
+Operators are identified by their symbol name rather than semantic meaning, since the
+same symbol can mean different things depending on operand types:
+
+- `*` (ASTERISK) — could be scalar multiplication, Hadamard product, or scale depending on types
+- `·` (DOT) — dot product
+- `×` (CROSS) — cross product
+- `⊕` (OPLUS) — direct sum or XOR
+
+Semantic resolution (e.g. `ASTERISK(matrix, matrix)` → Hadamard) is a separate
+type-inference pass, not part of the structural reduction.
+
+## ASCII Input for Special Symbols
+
+LaTeX-inspired escape sequences for entering special symbols in plain ASCII:
+
+- `\oplus` → ⊕
+- `\times` → ×
+- `\cdot` → ·
+- `\otimes` → ⊗
+
+`^` is reserved for superscript (not XOR), `_` for subscript. `S_12` reads as S₁₂.
+
+## Matrix Literals
+
+Single-line input using nested brackets:
+
+```
+[[1, 0, 0], [0, 1, 0], [0, 0, 1]]
+```
+
+Pretty-printed output using Unicode bracket characters:
+
+```
+⎡1 0 0⎤
+⎢0 1 0⎥
+⎣0 0 1⎦
+```
+
+## 2D Raster Reduction Scanner
+
+For parsing pretty-printed multi-line matrix literals within larger expressions like
+`M + 2 * N` where M and N are written in 2D notation, a raster-based reduction pass
+is needed before the standard 1D reduction pass.
+
+### Approach
+
+1. **Raster pass first** — operate on a 2D grid of characters
+2. Locate matrix corner anchors `⎡⎤⎣⎦` — these are highly selective so candidate
+   detection is cheap
+3. Scan right for `⎤`, down for `⎣`, verify `⎦` at intersection
+4. Use `⎢`/`⎥` to identify row boundaries within the region
+5. Collapse the identified rectangle into a single matrix token
+6. **1D pass second** — the surrounding expression now contains ordinary tokens and
+   the collapsed matrix nodes, reducible by standard rules
+
+### Scope Boundaries
+
+Fraction bars define containment — a matrix appearing in a numerator or denominator
+is only part of that sub-expression. The horizontal extent of the fraction bar bounds
+the operand scan. Containment must be resolved outside-in: find outermost structure
+first, recurse into sub-regions.
+
+### Generalization
+
+A 2D reduction scanner is a natural generalization of the 1D scanner — the "sequence"
+becomes a 2D array and conditions match spatial patterns rather than linear ones.
+The same anchor-point and backtracking concepts apply.

source/data/iteration-utilities.mjs

@@ -0,0 +1,31 @@
+export class Switchable_Iterator {
+	constructor(iterator=null, stack=[]) {
+		Object.assign(this, { iterator, stack });
+	}
+
+	push(iterator) {
+		this.stack.push(this.iterator);
+		this.switch_to(iterator);
+	}
+
+	pop(iterator) {
+		this.switch_to(this.stack.pop());
+	}
+
+	switch_to(iterator) {
+		this.iterator = iterator;
+	}
+
+	next() {
+		return this.iterator.next();
+	}
+
+	peek() {
+		return this.iterator.peek();
+	}
+
+	[Symbol.iterator]() {
+		return this;
+	}
+
+}

source/data/object-utilities.mjs

@@ -0,0 +1,9 @@
+
+export function assign_defined(target, source) {
+	Object.assign(target, Object.fromEntries(Object.entries(source).filter(([k ,v]) => v !== undefined )));
+}
+
+
+export function assign_using_predicate(target, source, kv_predicate) {
+	Object.assign(target, Object.fromEntries(Object.entries(source).filter(kv_predicate)));	// Call predicate with ([k, v])
+}

source/data/stack.mjs

@@ -0,0 +1,54 @@
+export const DELETE_PROPERTY = Symbol('DELETE_PROPERTY');
+
+
+export class String_Keyed_Stack {
+	constructor(target={}, stack=[]) {
+		Object.assign(this, { target, stack });
+	}
+
+	push(updates={}) {
+		const frame = {}
+		this.stack.push(frame);
+		for (const [key, value] of Object.entries(updates)) {
+
+			if (key in this.target) {
+				frame[key] = this.target[key];
+			} else {
+				frame[key] = DELETE_PROPERTY;
+			}
+
+			if (value === DELETE_PROPERTY) {
+				delete this.target[key];
+			} else {
+				this.target[key] = value;
+			}
+		}
+		return frame;
+	}
+
+	push_defined(updates={}) {
+		this.push(Object.fromEntries(Object.entries(updates).filter(([k ,v]) => v !== undefined )));
+	}
+
+	pop(copy_previous_state=false) {
+		const frame = this.stack.pop();
+		const { target } = this;
+
+		const return_value = copy_previous_state ? { ...target } : null;
+
+		for (const [key, value] of Object.entries(frame)) {
+			if (value === DELETE_PROPERTY) {
+				delete target[key];
+			} else {
+				target[key] = value;
+			}
+		}
+
+		return return_value;
+	}
+
+	get top_reverse_delta() {
+		return this.stack.at(-1);
+	}
+
+}

source/data/string-utilities.mjs

@@ -1,4 +1,4 @@
-import * as CF from '@efforting.tech/data/field-configuration-factories';
+import * as CF from '@efforting.tech/schema/field-configuration-factories';
 
 
 export const Indention_Mode = new CF.symbol_set({

source/errors.mjs

@@ -6,7 +6,7 @@ import { inspect } from 'node:util';
 
 export class Tokenization_Error extends Error {
 	constructor(data) {
-		const { parser, value, index, end_index } = data;
+		const {parser, text, start_position, end_position, match_start, match_end, value} = data;
 		super(`Tokenization_Error`);	//TODO: Format message
 		this.data = data;
 	}

source/feature/stub.mjs

@@ -0,0 +1,7 @@
+
+export function Stub(meta, name, description, module_name, function_name) {
+	return function stub() {
+		throw new Error(`The feature "${name}" of "${meta.url}" is not enabled. Enable it by calling "${function_name}(${this.name})" imported from "${module_name}"`);	//TODO - specific error
+	}
+}
+

source/parsing/generic-parsing.mjs

@@ -0,0 +1,100 @@
+import { RegExp_Token_Rule } from '@efforting.tech/parsing/regexp-dispatch';
+import { Switchable_Iterator } from '@efforting.tech/data/iteration-utilities';
+import { String_Keyed_Stack } from '@efforting.tech/data/stack';
+import { assign_defined } from '@efforting.tech/data/object-utilities';
+import * as F from '@efforting.tech/schema/field-configuration-factories';
+
+export class RegExp_Token_Parsing_Rule extends RegExp_Token_Rule {
+	constructor(pattern, action, identifier=undefined) {
+		super(pattern, identifier);
+		Object.assign(this, { action });
+	}
+}
+
+
+export const Parser_State = new F.Schema({
+
+	position: F.value(0, 'Pending position in source'),
+	value: F.factory(() => [], 'Pending value to return'),
+	sub_tokenizer_handlers: F.factory(() => [], 'Pending sub tokenizer handlers'),
+	tokenizer: F.value(null, 'Current tokenizer'),
+	context: F.value(null, 'User supplied context'),
+
+}, 'Parser state');
+
+
+
+export class Parser {
+	constructor(source, state=undefined) {
+		state = Parser_State.load(state);
+		const token_generator = new Switchable_Iterator();
+		const stack = new String_Keyed_Stack(state);
+		Object.assign(this, { source, state, stack, token_generator });
+		this.switch_to();
+	}
+
+
+	switch_to(tokenizer=undefined, position=undefined) {
+		assign_defined(this.state, { tokenizer, position });
+		this.token_generator.switch_to(this.state.tokenizer.iter_matches(this.source, this.state.position));
+	}
+
+	parse(handler=undefined) {
+
+		for (const match of this.token_generator) {
+			const { action } = match.rule;
+			if (!action) { continue; }
+
+			if (typeof action !== 'function') {	//TODO - proper error (possibly a warning, the warning is nice when you are developing, have to think about this one)
+				console.log('NOT IMPLEMENTED', match.rule.action);
+				continue;
+			}
+
+			this.state.position = match.pending_index;
+			this.state.match = match;
+			action(this, match);
+
+		}
+
+		if (handler) {
+			this.state.match = null;	//TODO: Decide if we should reset match here or not
+			handler(this, this.state.value);
+			return this.state.value;
+		} else {
+			return this.state.value;
+		}
+
+
+	}
+
+	push_token(...tokens) {
+		this.state.value.push(...tokens);
+	}
+
+	replace_value(value) {
+		this.state.value = value;
+	}
+
+	enter_sub_tokenizer(tokenizer=undefined, handler=undefined) {
+		this.stack.push_defined({ tokenizer, value: [] });
+		if (handler) {
+			this.state.sub_tokenizer_handlers.push(handler);
+		}
+		this.switch_to(tokenizer);
+	}
+
+	leave_sub_tokenizer(egress_match=null) {
+		const frame = this.stack.pop(true);
+		const { sub_tokenizer_handlers } = this.state;
+
+		if (sub_tokenizer_handlers.length) {
+			const handler = sub_tokenizer_handlers.pop();
+			this.state.match = null;	//TODO: Decide if we should reset match here or not
+			handler(this, frame.value, egress_match);
+		} else {
+			this.push_token(frame.value);
+		}
+		this.switch_to();
+	}
+
+}

source/parsing/regexp-dispatch.mjs

@@ -7,13 +7,24 @@ import { Tokenization_Error } from '@efforting.tech/errors';
 //
 //			Specifically it is not currently decided where the boundary between rule/action/capture should be
 
+
+function normalize_bounds(text, start_position, end_position) {
+	const len = text.length;
+	const norm_start = start_position < 0 ? Math.max(0, len + start_position) : start_position;
+	const norm_end = end_position == undefined ? undefined : (end_position < 0 ? Math.max(0, len + end_position) : end_position);
+	return [norm_start, norm_end];
+}
+
+
 export class Pattern_Match {
-	constructor(match, rule) {
-		Object.assign(this, { match, rule });
+	constructor(text, start_position, end_position, match, rule) {
+		// Normalize positions
+		[start_position, end_position] = normalize_bounds(text, start_position, end_position);
+		Object.assign(this, { text, start_position, end_position, match, rule });
 	}
 
 	get identifier() {
-		return this.rule. identifier;
+		return this.rule.identifier;
 	}
 
 	get value() {
@@ -24,28 +35,34 @@ export class Pattern_Match {
 		return this.match.slice(1);
 	}
 
-	get pending_index() {
-		return this.match.index + this.match[0].length;
+	get absolute_start() {
+		return this.match.index + this.start_position;
 	}
 
+	get absolute_end() {
+		return this.match.index + this.start_position + this.match[0].length - 1;
+	}
+
+	get pending_index() {
+		return this.match.index + this.start_position + this.match[0].length;
+	}
 }
 
 export class Default_Match {
-	constructor(text, index, end_index, action) {
-		const identifier = action(this);
-		Object.assign(this, { text, index, end_index, action, identifier });
-	}
+	//TBD: Here we invoke action while creating this object, and assign the identifier but we don't do that on Pattern_Match - this feels a bit sketchy
+	constructor(text, start_position, end_position, match_start, match_end, value, action) {
+		// Normalize positions
+		[start_position, end_position] = normalize_bounds(text, start_position, end_position);
+		[match_start, match_end] = normalize_bounds(text, match_start, match_end);
 
-	get value() {
-		return this.text;
+		const identifier = action(this);	//TODO: action protocol in accordance with issue #5
+		Object.assign(this, { text, start_position, end_position, match_start, match_end, value, action, identifier });
 	}
 
-
 	get pending_index() {
-		if (this.end_index === null) {
-			return null;
-		} else {
-			return this.end_index;
+		// CLARIFICATION: loose inequality ( != ) matches null and undefined but not false/0/'' but we use strict for start_position since it is always a number
+		if (this.match_end != undefined) {
+			return this.match_end + 1;
 		}
 	}
 }
@@ -70,12 +87,13 @@ export class Abstract_RegExp_Token_Rule {
 }
 
 export class RegExp_Token_Rule extends Abstract_RegExp_Token_Rule {
-	constructor(pattern, identifier=this) {
+	constructor(pattern, identifier=undefined) {
 		super(pattern);
-		Object.assign(this, { identifier });
+		Object.assign(this, { identifier: identifier ?? this });
 	}
 }
 
+
 export class RegExp_Tokenizer {
 	constructor(rules=[], default_action=undefined) {
 		Object.assign(this, { rules, default_action });
@@ -91,53 +109,58 @@ export class RegExp_Tokenizer {
 		this.rules.push(...rules_to_add);
 	}
 
-	immediate_match(text, position=0) {
+	immediate_match(text, start_position=0, end_position=undefined) {
+		// CLARIFICATION: loose inequality ( != ) matches null and undefined but not false/0/'' but we use strict for start_position since it is always a number
+		const bounded = start_position !== 0 || end_position != undefined;
+		const text_to_search = bounded ? text.slice(start_position, end_position) : text;
+
 		for (const rule of this.rules) {
 			const pattern = rule.immediate_pattern;
-			pattern.lastIndex = position;
-			const match = pattern.exec(text);
+			pattern.lastIndex = 0;
+			const match = pattern.exec(text_to_search);
 			if (match) {
-				return new Pattern_Match(match, rule);
+				return new Pattern_Match(text, start_position, end_position, match, rule);
 			}
 		}
 	}
 
 
-	_handle_default_match(value, index, end_index=null) {
+	_handle_default_match(text, start_position, end_position, match_start, match_end, value) {
 		const { default_action } = this;
 		if (!default_action) {
-			throw new Tokenization_Error({ parser: this, value, index, end_index });
+			throw new Tokenization_Error({ parser: this, text, start_position, end_position, match_start, match_end, value });
 		}
-		return new Default_Match(value, index, end_index, default_action);
+		return new Default_Match(text, start_position, end_position, match_start, match_end, value, default_action);
 	}
 
 
-	closest_scanning_match(text, position=0) {
-		const immediate_match = this.immediate_match(text, position);
+	closest_scanning_match(text, start_position=0, end_position=undefined) {
+
+		const immediate_match = this.immediate_match(text, start_position, end_position);
 		if (immediate_match) {
 			return immediate_match;
 		}
 
 		let best_candidate;
-		for (const candidate of this.iter_scanning_rule_candidates(text, position)) {
-			if ((best_candidate === undefined) || (best_candidate.match.index > candidate.match.index)) {
+		for (const candidate of this.iter_scanning_rule_candidates(text, start_position, end_position)) {
+			if ((best_candidate === undefined) || (best_candidate.absolute_start > candidate.absolute_start)) {
 				best_candidate = candidate;
 			}
 		}
 
 		// There was no match, just get the tail
 		if (!best_candidate) {
-			const tail = text.slice(position);
+			const tail = text.slice(start_position);
 			if (tail.length) {
-				return this._handle_default_match(tail, position);
+				return this._handle_default_match(text, start_position, end_position, start_position, end_position, tail);
 			}
 		}
 
 		// There was a match, check the head
 		if (best_candidate) {
-			const head = text.slice(position, best_candidate.match.index);
+			const head = text.slice(start_position, best_candidate.absolute_start);
 			if (head.length) {
-				return this._handle_default_match(head, position, best_candidate.match.index);
+				return this._handle_default_match(text, start_position, end_position, start_position, best_candidate.absolute_start - 1, head);
 			}
 		}
 
@@ -146,32 +169,41 @@ export class RegExp_Tokenizer {
 	}
 
 
-	*iter_scanning_rule_candidates(text, position=0) {
-		// Iterates over all rules and yields any matches found anywhere (but only once per rule)
+	*iter_scanning_rule_candidates(text, start_position=0, end_position=undefined) {
+		// CLARIFICATION: loose inequality ( != ) matches null and undefined but not false/0/'' but we use strict for start_position since it is always a number
+		const bounded = start_position !== 0 || end_position != undefined;
+		const text_to_search = bounded ? text.slice(start_position, end_position) : text;
 
+
+		// Iterates over all rules and yields any matches found anywhere (but only once per rule)
 		for (const rule of this.rules) {
 			const pattern = rule.scanning_pattern;
-			pattern.lastIndex = position;
-			const match = pattern.exec(text);
+			pattern.lastIndex = 0;
+			const match = pattern.exec(text_to_search);
 
 			if (match) {
-				yield new Pattern_Match(match, rule);
+				yield new Pattern_Match(text, start_position, end_position, match, rule);
 			}
 		}
 
 	}
 
 
-	*iter_matches(text, position=0) {
+	*iter_matches(text, start_position=0, end_position=undefined) {
+
+		// Normalize positions
+		[start_position, end_position] = normalize_bounds(text, start_position, end_position);
+
 		while (true) {
-			const pending = this.closest_scanning_match(text, position);
+			const pending = this.closest_scanning_match(text, start_position, end_position);
 			if (pending) {
 				yield pending;
 			}
-			if (!pending || pending.pending_index === null) {
+			// CLARIFICATION: loose equality ( == ) matches null and undefined but not false/0/'' but we use strict for start_position since it is always a number
+			if (!pending || pending.pending_index == null || pending.pending_index === end_position ) {
 				break;
 			}
-			position = pending.pending_index;
+			start_position = pending.pending_index;
 
 		}
 	}

source/rule-processing/reduction-scanner.mjs

@@ -1,7 +1,5 @@
 import { Reduction_Contract, FPR_Contract } from './contracts.mjs';
-
-
-import * as CF from '@efforting.tech/data/field-configuration-factories';
+import * as CF from '@efforting.tech/schema/field-configuration-factories';
 
 
 export const Reduction_Order = new CF.symbol_set({
@@ -25,6 +23,8 @@ export const FP_Reduction_Settings = new CF.Schema({
 
 
 
+//TODO - we should probably have a pre-defined record shape as argument for actions and such rather than using an ever growing list of positionals or an anonymous Object()
+
 export class Reduction_Scanner {
 
 	static settings_schema = Reduction_Settings;
@@ -38,38 +38,58 @@ export class Reduction_Scanner {
 		}
 	}
 
-	perform_reduction(sequence) {
+	find_reduction_candidate(sequence) {
 		const { settings } = this;
 		switch (settings.reduction_order) {
 
 			case Reduction_Order.symbols.RULE_MAJOR:
 				for (const rule of settings.rules) {
-					for (let start_index=0; start_index < sequence.length; start_index++) {
-						const match = rule.match(sequence, start_index);
-						if (match) {
-							rule.action(this, sequence, match);
-							return true;
-						}
+					const match = rule.match(sequence);
+					if (match) {
+						return { sequence, rule, match };
 					}
 				}
-				return false;
+				return;
 
 			case Reduction_Order.symbols.POSITION_MAJOR:
-				for (let start_index=0; start_index < sequence.length; start_index++) {
-					for (const rule of settings.rules) {
-						const match = rule.match(sequence, start_index);
-						if (match) {
-							rule.action(this, sequence, match);
-							return true;
+
+				let best_match, best_rule;
+
+				for (const rule of settings.rules) {
+					const match = rule.match(sequence);
+
+					if (match)  {
+						if (!best_match || best_match.match_start > match.match_start) {
+							//TODO - early return if start of sequence
+							best_match = match;
+							best_rule = rule;
 						}
 					}
 				}
-				return false;
+
+				if (best_match) {
+					return { sequence, rule: best_rule, match: best_match };
+				}
+
+
+				return;
 			default:
 				throw new Error(`Unknown reduction order: ${this.reduction_order}`);	//TODO: Force invalid configuration  error
 
 		}
+	}
 
+
+	perform_reduction(sequence) {
+		const candidate = this.find_reduction_candidate(sequence);
+		if (candidate) {
+			const { sequence, rule, match } = candidate;
+			//console.log('ACT', match.match)
+			match.action({ reduction_system: this, rule, sequence, match: match.match });
+			return true;
+		} else {
+			return false;
+		}
 	}
 
 	clear_transform_state() {

source/rule-processing/resolvers.mjs

@@ -1,5 +1,7 @@
 import { Item_Unresolvable } from '@efforting.tech/errors';
 
+//TODO: Should this be integrated with rules.mjs for predicates? Possibly a normalization step during rule insertion.
+
 export class Abstract_Resolver {
 	resolve(item, extra_info={}) {
 		const result = this.resolve_handler(item, extra_info);

source/rule-processing/rules.mjs

@@ -0,0 +1,108 @@
+
+const ABORT_SEQUENCE = Symbol('ABORT_SEQUENCE');
+
+export class Abstract_Item_Condition {
+	match(sequence, context={}) {
+		return this.match_value(sequence[context.start_index ?? 0], context);
+	}
+
+}
+
+export class Abstract_Sequence_Condition {
+}
+
+export class Match {
+	constructor(rule, value, context) {
+		Object.assign(this, { rule, value, ...context });
+	}
+}
+
+export class Predicate extends Abstract_Item_Condition {
+	constructor(predicate) {
+		super();
+		Object.assign(this, { predicate });
+	}
+
+	match_value(item, context={}) {
+		if (this.predicate(item, context)) {
+			const si = context.start_index ?? 0;
+			return new Match(this, item, { ...context, match_start: si, match_end: si });
+		};
+	}
+
+}
+
+export class Type_Is extends Abstract_Item_Condition {
+	constructor(type) {
+		super();
+		Object.assign(this, { type });
+	}
+
+	match_value(item, context={}) {
+		if (typeof item === this.type) {
+			const si = context.start_index ?? 0;
+			return new Match(this, item, { ...context, match_start: si, match_end: si });
+		};
+	}
+
+}
+
+export class Strict_Equality extends Abstract_Item_Condition {
+	constructor(value) {
+		super();
+		Object.assign(this, { value });
+	}
+
+	match_value(item, context={}) {
+		if (item === this.value) {
+			const si = context.start_index ?? 0;
+			return new Match(this, item, { ...context, match_start: si, match_end: si });
+		}
+	}
+
+}
+
+
+export class Sequence_Condition extends Abstract_Sequence_Condition {
+	constructor(sequence) {
+		super();
+		Object.assign(this, { sequence });
+	}
+
+	match(sequence, context={}) {
+		//TODO: For anchors we need anchor_start_index and anchor_end_index (compare with regexp ^ and $)
+		const start_index = context.start_index ?? 0;
+		const end_index = context.end_index ?? sequence.length - 1;
+
+		const match_from = (sequence_index, pattern_index=0) => {
+
+			if (pattern_index === this.sequence.length) {
+				return [];
+			}
+
+			//TODO - There are plenty of optimizations to be implemented here but we must be suer they are correct - we will start naively
+			const sub_condition = this.sequence[pattern_index];
+			const sub_match = sub_condition.match(sequence, { ...context, start_index: sequence_index });
+
+			//console.log('match_from', {sequence_index, pattern_index, sub_condition, sub_match})
+
+			if (sub_match) {
+				const remaining = match_from(sub_match.match_end + 1, pattern_index + 1);
+				if (remaining) {
+					return [sub_match, ...remaining];
+				}
+			}
+
+		}
+
+		for (let i=start_index; i<=end_index; i++) {
+			const m = match_from(i);
+			if (m) {
+				// NOTE: If result is empty array which can be a positive match, match_start and match_end will be undefined which is by design
+				return new Match(this, m, { match_start: m.at(0)?.match_start, match_end: m.at(-1)?.match_end, ...context});
+			}
+		}
+
+	}
+
+}

source/rule-processing/state-serializer.mjs

@@ -1,4 +1,4 @@
-import * as CF from '@efforting.tech/data/field-configuration-factories';
+import * as CF from '@efforting.tech/schema/field-configuration-factories';
 
 
 export const Object_Serialization_Strategy = new CF.Schema({

source/table/raster-table.mjs

@@ -0,0 +1,46 @@
+import { tabs_to_spaces } from '@efforting.tech/text/text-utilities';
+
+const raster_table_pattern = /^((?:[^\S\n]|[\w-])+)\n((?:[^\S\n]|-)+)\n(.+)/ms;
+const column_pattern = /\s*(.+?)(?=\s{2,}|$)/gd;
+const row_pattern = /^(.+)$/mg
+
+// If loader is null we return a raw representation
+export function load_raster_table(raster, loader=null, tab_width=4, null_padding=true) {
+	if (raster.match(/\t/g)) {
+		raster = tabs_to_spaces(raster, tab_width);
+	}
+
+	if (null_padding) {	//TODO - this is just experimental proof of concept
+		raster = raster.replace(/〃/g, '\0〃');
+	}
+
+
+	const m = raster.match(raster_table_pattern);
+	const column_matches = [...m[1].matchAll(column_pattern)];
+	const column_positions = [...column_matches.map(cm => cm.indices[1][0])]
+	const column_names = [...column_matches.map(cm => cm[1])]
+	const rows = [];
+
+	for (const row of m[3].matchAll(row_pattern)) {
+
+		const pending_row = [];
+		for (let ci=0; ci<column_positions.length; ci++) {
+			const cell = row[1].slice(column_positions[ci], column_positions[ci+1]);
+			if (null_padding) {
+				pending_row.push(cell.replace(/\0/, ''));
+			} else {
+				pending_row.push(cell);
+			}
+		}
+		rows.push(pending_row);
+	}
+
+	if (loader) {
+		return new loader({ rows, column_names });
+	} else {
+		return {column_names, column_positions, rows};
+	}
+}
+
+
+//TODO: load_ditto_raster_table

source/table/table.mjs

@@ -0,0 +1,165 @@
+import * as F from '@efforting.tech/schema/field-configuration-factories';
+import { parse_csv } from '@efforting.tech/data/string-utilities';
+
+export const Row_Based_Table_Settings = new F.Schema({
+
+	rows: F.factory(() => [], 'Rows to initialize table with'),
+	row_names: F.typed_factory((v) => typeof v === 'string' ? parse_csv(v) : v, () => [], 'Names of rows'),
+	column_names: F.typed_factory((v) => typeof v === 'string' ? parse_csv(v) : v, () => [], 'Names of columns'),
+
+}, 'Row based table settings');
+
+
+export class Table_Row_Reference {
+
+	constructor(table, index, snapshot=null) {
+		Object.assign(this, { table, index, snapshot });
+	}
+
+	get value() {
+		const { table, index, snapshot } = this;
+		return snapshot ?? table.read_row(index);
+	}
+
+	get object() {
+		const { table, index, snapshot } = this;
+		const { column_names } = table;
+		const value = snapshot ?? table.read_row(index);
+		//TODO - check shape of column_names vs the value
+
+		return Object.fromEntries(value.map((cell, column_index) => [column_names[column_index], cell]));
+	}
+
+
+	update(updates) {
+		const { table, index, snapshot } = this;
+		if (snapshot) {
+			throw new Error('Can not update snapshot references, clear the snapshot to reuse this index');	//TODO - proper error
+		}
+		table.write_row(index, updates);
+	}
+
+}
+
+export class Row_Based_Table {
+
+	constructor(settings) {
+		const { rows, column_names, row_names } = Row_Based_Table_Settings.load(settings);
+		Object.assign(this, { rows });
+		this.set_column_names(...column_names);
+		this.set_row_names(...row_names);
+	}
+
+	// General operations
+
+	get width() {
+		const { rows, column_names } = this;
+		return rows[0]?.length || column_names.length || undefined;
+	}
+
+	get length() {
+		const { rows } = this;
+		return rows.length;
+	}
+
+	get size() {
+		const { width, length } = this;
+		return [width, length];
+	}
+
+	replace_all_cells(replacement_fn) {
+
+		for (const [row_index, row] of this.rows.entries()) {
+			const pending_row = [];
+			for (const [column_index, cell] of row.entries()) {
+				const row_name = this.row_names[row_index];
+				const column_name = this.column_names[column_index];
+				pending_row.push(replacement_fn({ row_name, column_name, row_index, column_index, row, cell }));
+			}
+			this.rows[row_index] = pending_row;
+		}
+
+
+	}
+
+	// TODO: Make sure column and row operations covers the same uses
+	// TODO: Sub table operations
+
+	// Column operations
+
+	set_column_names(...names) {
+		this.column_names = names;
+		this.column_names_lut = Object.fromEntries(names.map((name, index) => [name, index]));
+	}
+
+	// Row operations
+
+	set_row_names(...names) {
+		this.row_names = names;
+		this.row_names_lut = Object.fromEntries(names.map((name, index) => [name, index]));
+	}
+
+	read_rows(...indices) {
+		const result = [];
+		for (const index of indices) {
+			result.push(new Table_Row_Reference(this, index));
+		}
+		return result;
+	}
+
+	snapshot_rows(...indices) {
+		//NOTE: Snapshot doesn't include current layout or other settings, just the contents of the row at the time, and it currently is a shallow copy
+		const result = [];
+		for (const index of indices) {
+			result.push(new Table_Row_Reference(this, index, [...this.rows[index]]));
+		}
+		return result;
+	}
+
+	push_rows(...rows) {
+		//TODO - verify shape
+		this.rows.push(...rows);
+	}
+
+	read_row(index) {
+		return this.rows[index];
+	}
+
+	write_row(index, row_data) {
+		const { rows, column_names_lut } = this;
+		if (Array.isArray(row_data)) {
+			//TODO - shape check
+			rows[index] = row_data;
+		} else {
+			//TODO - possibly allow array of array for using numerical indices
+			const work_row = rows[index];
+			for (const [key, value] of Object.entries(row_data)) {
+				const col_index = column_names_lut[key];
+
+				if (col_index === undefined) {
+					throw new Error(`Unknown column: ${key}`);	//TODO - proper error
+				}
+
+				work_row[col_index] = value;
+			}
+		}
+	}
+
+
+	//TODO: Implement map and other functions expected by collections
+
+	*[Symbol.iterator]() {
+		for (const index of this.rows.keys()) {
+			yield new Table_Row_Reference(this, index);
+		}
+	}
+
+	*iter_objects() {
+		for (const index of this.rows.keys()) {
+			yield new Table_Row_Reference(this, index).object;
+		}
+	}
+
+
+}
+

source/text/basic-tree.mjs

@@ -1,6 +1,5 @@
-import { string_has_contents, indented_line_iterator } from  '@efforting.tech/data/string-utilities';
-import * as CF from '@efforting.tech/data/field-configuration-factories';
-import { Text_Settings } from  '@efforting.tech/data/string-utilities';
+import { Text_Settings, string_has_contents, indented_line_iterator } from  '@efforting.tech/data/string-utilities';
+import * as CF from '@efforting.tech/schema/field-configuration-factories';
 
 export const Text_Tree_Settings = new CF.Schema({
 	//BUG - there is currently no way (I think) to put defaults into a sub schema - this should be fixed

source/text/text-utilities.mjs

@@ -0,0 +1,30 @@
+export const char_width_lut = {
+	'〃': 2,
+}
+
+
+//NOTE - this one only support posix newlines, this should be fixed later
+export function tabs_to_spaces(text, tab_width=4) {
+	let pending_column_index=0;
+
+	let result = '';
+	for (const char of text) {
+		if (char == '\t') {
+			const new_column_index = (Math.floor(pending_column_index / tab_width) + 1) * tab_width;
+			result += ' '.repeat(new_column_index - pending_column_index);
+			pending_column_index = new_column_index;
+		} else {
+			if (char.charCodeAt(0) === 10) {
+				result += '\n';
+				pending_column_index = 0;
+/*			} else if (char.charCodeAt(0) < 32) {
+				result += '<27>';
+*/			} else {
+				pending_column_index += (char_width_lut[char] ?? 1)
+				result += char;
+			}
+		}
+	}
+	return result;
+
+}

tools/stage-for-npm.mjs

@@ -88,6 +88,9 @@ for (const [package_name, package_data] of Object.entries(manifest.packages)) {
 	const linked_docs = pkg.documentation ? link_tree(pkg.documentation, pkg_dir).map(p => path.relative(pkg_dir, p)) : [];
 	//console.log('DOCS', { linked_docs });
 
+
+	// A file named after its package (e.g. table.mjs in the table package) becomes the root export '.'
+	// All other files become named subpath exports e.g. './raster-table'
 	const exports_map = {};
 	for (const file of linked_sources) {
 		const name = path.basename(file, '.mjs');
@@ -145,11 +148,15 @@ const publish_script = (
 	`${publish_script_lines.join('\n')}\n`
 );
 
+const repo_root = path.resolve(output_directory, '../..');
+const experiments_link_line = `mkdir -p "${repo_root}/experiments/node_modules"\nln -sf "../../build/packages" "${repo_root}/experiments/node_modules/@efforting.tech"`;
+
 const dev_stage_script = (
 	'#!/usr/bin/env bash\n' +
 	'set -e\n' +
 	`${dev_stage_mkdir_lines.join('\n')}\n` +
-	`${dev_stage_script_lines.join('\n')}\n`
+	`${dev_stage_script_lines.join('\n')}\n` +
+	experiments_link_line
 );