/*
 * test_formatter_labels_grammar.lime -- regression fixture for
 * Lime-Letter-20 (PostgreSQL migration team).
 *
 * v0.3.2's formatter stripped LHS / RHS letter labels (`(A)`,
 * `(B)`, etc.) from rule headers while keeping action-body
 * references to those labels.  Result: formatted grammars
 * compiled by lime -> .c -> gcc broke at gcc with "undeclared
 * identifier" errors on every action body that referenced a
 * stack-slot alias.
 *
 * v0.3.2 also stripped explicit `[SYMBOL]` precedence markers
 * from rules, silently changing parser semantics around unary
 * operators.
 *
 * This fixture exercises both invariants:
 *   - LHS labels: `expr(A) ::= ...`
 *   - RHS labels: `... PLUS expr(B).`
 *   - Multiple labels per rule: `(A) ::= (B) PLUS (C).`
 *   - Single-letter labels: A, B, C
 *   - Multi-character labels: `Lhs`, `Rhs`
 *   - Explicit precedence: `[UMINUS]`
 *   - Mixed labeled + unlabeled symbols on the same RHS
 *
 * The driver asserts the formatted output contains every label
 * AND idempotence (format(format(F)) == format(F)).
 */

%name FmtLabelsTest
%token_type {int}
%type expr {int}
%extra_argument {int *result}

%left PLUS.
%left TIMES.
%right UMINUS.

%token PLUS TIMES MINUS LPAREN RPAREN INTEGER.

%include {
#include <stdio.h>
}

/* expr is the arithmetic expression non-terminal.  All actions
 * reference letter-aliased stack slots. */
program(P) ::= expr(A).               { P = A; *result = A; }

/* Multi-label, multi-RHS aliases. */
expr(R) ::= expr(L) PLUS expr(M).     { R = L + M; }
expr(R) ::= expr(L) TIMES expr(M).    { R = L * M; }

/* Mixed labeled + unlabeled symbols (LPAREN / RPAREN unaliased). */
expr(R) ::= LPAREN expr(M) RPAREN.    { R = M; }

/* Single-RHS-symbol with label. */
expr(R) ::= INTEGER(N).               { R = N; }

/* Explicit precedence marker -- the [UMINUS] must round-trip. */
expr(R) ::= MINUS expr(M). [UMINUS]   { R = -M; }