Crate elenchus_parser 

elenchus-parser — parses the English-like elenchus DSL into an AST.

Style mirrors vsm-parser: zero-copy over &str, nom + nom_locate for line/column tracking, and a human-friendly ^--- here error display. Syntax is line/keyword-oriented (not S-expressions) so small models cannot trip on parentheses or indentation.

Grammar (see docs/SPEC.md, “Grammar (EBNF)”):

• statements are newline-terminated; indentation is cosmetic, not significant;
• keywords are ALWAYS CAPS (ASCII); identifiers are content (case-sensitive, verbatim, any-script letters — e.g. условие, 名前);
• block boundaries (PREMISE/RULE bodies) are found by keywords, never by indent.

Structs

Atom

An atom is the triple (subject, predicate, object?) — the unit of identity. Creature.A has flying and Creature.A has swimming are DIFFERENT atoms.

Literal

A literal is an atom, optionally negated (NOT ...).

Located

Container for data associated with its source location.

ParseError

A friendly error structure that can be displayed to the user.

Program

A parsed program: a flat sequence of statements.

Enums

Body

The body of an PREMISE or RULE.

Conn

How the literals in a WHEN/THEN group combine. A single-literal group is always Conn::And (the connective is irrelevant with one literal).

ListOp

List constraint operators (body of a list-style PREMISE).

Statement

A top-level statement.

Constants

RESERVED

Reserved words — always CAPS, in full. An identifier may not equal any of these.

Functions

is_reserved

Whether word is a reserved keyword.

parse

Parse a full .vrf source into a Program.

Type Aliases

Span

Source code fragment with line and column tracking.