From 60a142f90c681f5d25e29fc8cb6761fbe2094569 Mon Sep 17 00:00:00 2001
From: Jack Firth <jackhfirth@gmail.com>
Date: Wed, 13 Apr 2022 17:40:57 -0700
Subject: [PATCH] Move symbols into their own module too

---
 base/grammar.rkt  | 15 ++-------------
 base/symbol.rkt   | 22 ++++++++++++++++++++++
 parser/earley.rkt |  2 ++
 3 files changed, 26 insertions(+), 13 deletions(-)
 create mode 100644 base/symbol.rkt

diff --git a/base/grammar.rkt b/base/grammar.rkt
index 8538b5b..991f26c 100644
--- a/base/grammar.rkt
+++ b/base/grammar.rkt
@@ -5,12 +5,9 @@
 
 
 (provide
- (struct-out terminal-symbol)
- (struct-out nonterminal-symbol)
  (struct-out cf-grammar)
  (struct-out cf-production-rule)
  (contract-out
-  [grammar-symbol? predicate/c]
   [cf-grammar-start-rules (-> cf-grammar? (set/c cf-production-rule? #:kind 'immutable))]
   [make-cf-grammar (-> #:rules (sequence/c cf-production-rule?) #:start-symbol any/c cf-grammar?)]
   [make-cf-production-rule
@@ -22,7 +19,8 @@
          racket/set
          rebellion/collection/vector
          yaragg/base/derivation
-         yaragg/base/semantic-action)
+         yaragg/base/semantic-action
+         yaragg/base/symbol)
 
 
 ;@----------------------------------------------------------------------------------------------------
@@ -52,15 +50,6 @@
 (struct cf-production-rule (nonterminal action substitution) #:transparent)
 
 
-;; A (Grammar-Symbol T S) is either a (Terminal-Symbol T) or a (Nonterminal-Symbol S)
-(define (grammar-symbol? v)
-  (or (terminal-symbol? v) (nonterminal-symbol? v)))
-
-
-(struct terminal-symbol (value) #:transparent)
-(struct nonterminal-symbol (value) #:transparent)
-
-
 (define (make-cf-grammar #:rules rules #:start-symbol start)
   (cf-grammar (sequence->vector rules) start))
 
diff --git a/base/symbol.rkt b/base/symbol.rkt
new file mode 100644
index 0000000..7f64b8d
--- /dev/null
+++ b/base/symbol.rkt
@@ -0,0 +1,22 @@
+#lang racket/base
+
+
+(require racket/contract/base)
+
+
+(provide
+ (struct-out terminal-symbol)
+ (struct-out nonterminal-symbol)
+ (contract-out
+  [grammar-symbol? predicate/c]))
+
+
+;@----------------------------------------------------------------------------------------------------
+
+
+(define (grammar-symbol? v)
+  (or (terminal-symbol? v) (nonterminal-symbol? v)))
+
+
+(struct terminal-symbol (value) #:transparent)
+(struct nonterminal-symbol (value) #:transparent)
diff --git a/parser/earley.rkt b/parser/earley.rkt
index 0d68425..94b5f05 100644
--- a/parser/earley.rkt
+++ b/parser/earley.rkt
@@ -18,6 +18,8 @@
          rebellion/private/guarded-block
          yaragg/base/derivation
          yaragg/base/grammar
+         yaragg/base/semantic-action
+         yaragg/base/symbol
          yaragg/base/token
          yaragg/parser
          (submod yaragg/parser private))