Module parser 

Recursive descent parser for natural language to first-order logic.

This module implements a hand-written recursive descent parser that transforms natural language sentences into logical expressions. The parser operates in two modes: Declarative for natural language propositions (Logicaffeine mode) and Imperative for strict, deterministic scoping (LOGOS mode).

Architecture

The parser is split into specialized submodules:

Module	Responsibility
clause	Sentence-level parsing: conditionals, conjunctions, relative clauses
noun	Noun phrase parsing with determiners, adjectives, possessives
verb	Verb phrase parsing, event semantics, thematic roles
modal	Modal verbs (can, must, might) with Kripke semantics
quantifier	Quantifier scope: every, some, no, most
question	Wh-movement and question formation
pragmatics	Pragmatic inference during parsing
common	Shared utilities (copula lists, etc.)

Key Types

• Parser: The main parser struct holding tokens, state, and arenas
• ParserMode: Declarative (NL) vs Imperative (LOGOS) mode
• ParserGuard: RAII guard for speculative parsing with automatic rollback
• NegativeScopeMode: Wide vs narrow scope for lexically negative verbs
• ModalPreference: Default, epistemic, or deontic readings for modals

Example

use logicaffeine_language::parser::{Parser, ParserMode};

// Lexer produces tokens, then parser produces LogicExpr
let expr = parser.parse_sentence()?;

Structs

EventTemplate

Template for constructing Neo-Davidsonian events.

Parser

Recursive descent parser for natural language to first-order logic.

ParserGuard

RAII guard for speculative parsing with automatic rollback.

Enums

ModalPreference

Controls interpretation of polysemous modals (may, can, could). Used by compile_forest to generate multiple semantic readings.

NegativeScopeMode

Controls scope of negation for lexically negative verbs (lacks, miss). “user who lacks a key” can mean:

ParserMode

Determines how the parser interprets sentences.

ResolvedPronoun

Result of pronoun resolution during parsing.

Traits

ClauseParsing

Trait for parsing clause-level structures.

ImperativeVerbParsing

Trait for parsing verb phrases in imperative (LOGOS) mode.

LogicVerbParsing

Trait for parsing verb phrases in declarative (logic) mode.

ModalParsing

Trait for parsing modal verbs and aspect chains.

NounParsing

Trait for parsing noun phrases.

PragmaticsParsing

Trait for parsing pragmatic and focus-sensitive constructions.

QuantifierParsing

Trait for parsing quantified expressions and managing scope.

QuestionParsing

Trait for parsing interrogative sentences.