refactor: replace string-based formula representation with interned SymbolIds and introduce stateful Clausifier for TPTP parsing

1 files changed, 62 insertions, 12 deletions

diff --git a/include/atp/frontend/tptp_parser.h b/include/atp/frontend/tptp_parser.h
index f43f020..075b45e 100644
--- a/include/atp/frontend/tptp_parser.h
+++ b/include/atp/frontend/tptp_parser.h
@@ -16,13 +16,21 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-
 #pragma once
 
 /// @file tptp_parser.h
-/// @brief Bridge from ANTLR4-generated parse tree to internal Formula AST.
+/// @brief TPTP format parser — converts .p files to internal representations.
+///
+/// The parser interns all symbols (predicates, functions, variables) into the
+/// SymbolTable and builds terms in the TermBank during parsing. This is the
+/// E Prover approach: parse and intern simultaneously, avoiding a separate
+/// resolution pass.
+///
+/// V1: Hand-written recursive descent for TPTP CNF/FOF subset.
+///     (ANTLR4 integration deferred — avoids build complexity for V1.)
 
 #include "atp/core/clause.h"
+#include "atp/core/symbol_table.h"
 #include "atp/core/term_bank.h"
 #include "atp/normalize/formula.h"
 
@@ -31,22 +39,64 @@
 
 namespace atp {
 
-/// Role of a TPTP formula (axiom, hypothesis, conjecture, etc.)
+/// Role of a TPTP formula.
+/// See TPTP spec: https://www.tptp.org/TPTP/SyntaxBNF.html
 enum class FormulaRole : uint8_t {
-    kAxiom,
-    kHypothesis,
-    kConjecture,
-    kNegatedConjecture,
+    kAxiom,                ///< Background truth
+    kHypothesis,           ///< Problem-specific assumption
+    kDefinition,           ///< Symbol definition (can be unfolded)
+    kAssumption,           ///< Assumed for this proof attempt
+    kLemma,                ///< Derived intermediate result
+    kTheorem,              ///< Previously proved statement (used as axiom)
+    kConjecture,           ///< The statement to prove
+    kNegatedConjecture,    ///< Already negated conjecture (input was cnf)
+    kPlain,                ///< No semantic role specified
 };
 
+/// Map a TPTP role string to enum. Returns kPlain for unknown roles.
+FormulaRole parseRole(std::string_view role_str);
+
 /// A parsed TPTP formula with its name and role.
 struct AnnotatedFormula {
-    std::string name;
-    FormulaRole role;
-    std::unique_ptr<Formula> formula;
+    std::string name;                  ///< Formula name (e.g., "axiom1")
+    FormulaRole role;                  ///< Semantic role
+    std::unique_ptr<Formula> formula;  ///< The FOL formula (for fof(...))
+    std::vector<Clause> clauses;       ///< Direct clauses (for cnf(...))
+    bool is_cnf = false;               ///< true if input was cnf(), false if fof()
+};
+
+/// A complete parsed TPTP problem.
+struct ParsedProblem {
+    std::vector<AnnotatedFormula> formulas;
+
+    /// Does any formula contain an equality predicate?
+    bool has_equality = false;
+
+    /// Original file path (for error messages).
+    std::string source_file;
 };
 
-/// Parse a TPTP file and return the annotated formulas.
-std::vector<AnnotatedFormula> parseTptpFile(const std::string& filepath, TermBank& bank);
+/// Parse a TPTP file.
+///
+/// For `cnf(...)` entries: clauses are built directly (no clausification needed).
+/// For `fof(...)` entries: Formula AST is built (clausification happens later).
+///
+/// All symbols are interned into `symbols` and terms into `bank` during parsing.
+ParsedProblem parseTptpFile(const std::string& filepath,
+                            TermBank& bank, SymbolTable& symbols);
+
+/// Parse a TPTP string (for testing).
+ParsedProblem parseTptpString(const std::string& input,
+                              TermBank& bank, SymbolTable& symbols);
+
+/// Prepare a parsed problem for proving:
+///   1. Negate conjecture formulas.
+///   2. Clausify all fof() formulas.
+///   3. Collect all cnf() clauses directly.
+///   4. Assign ClauseIds and set provenance to kInput.
+///
+/// Returns the final clause set ready for the Prover.
+std::vector<Clause> prepareForProving(ParsedProblem& problem,
+                                      TermBank& bank, SymbolTable& symbols);
 
 }  // namespace atp