af48dccaec7297a6031a6f12cafc4b4df438ffa5
kent
  Wed Aug 14 19:08:18 2019 -0700
Passing symbol table to parse for better error checking.

diff --git src/inc/strex.h src/inc/strex.h
index 359079d..ac5320c 100644
--- src/inc/strex.h
+++ src/inc/strex.h
@@ -1,30 +1,31 @@
 /* strex.h - interface to string expression language,  currently used in tabToTabDir
  * to describe how the output fields are filled in from input fields. */
 
 #ifndef STREX_H
 #define STREX_H
 
 /* Parsing out something into strex */
 struct strexParse;    /* A parser generated tree */
 
-struct strexParse *strexParseString(char *s, char *fileName, int fileLineNumber);
+typedef char* (*StrexLookup)(void *symbols, char *key);
+/* Callback to lookup value of key in a symbol table. */
+
+struct strexParse *strexParseString(char *s, char *fileName, int fileLineNumber,
+    void *symbols, StrexLookup lookup);
 /* Parse out string expression in s and return root of tree. The fileName and 
  * fileLineNumber are just used in the error message.  Ideally they should help 
- * the user navigate to where the problem was. */
+ * the user navigate to where the problem was. 
+ *    If symbols is non-null then it and lookup will be used together to complain
+ *    about missing variables rather than just generating empty strings when 
+ *    they are referenced. */
 
 void strexParseDump(struct strexParse *p, int depth, FILE *f);
 /* Dump out strexParse tree and children for debugging.  Usual depth is 0. */
 
-
-
 /* Evaluating a parsed out strex expression */
-
-typedef char* (*StrexEvalLookup)(void *symbols, char *key);
-/* Callback to lookup value of key in a symbol table. */
-
-char *strexEvalAsString(struct strexParse *p, void *symbols, StrexEvalLookup lookup);
+char *strexEvalAsString(struct strexParse *p, void *symbols, StrexLookup lookup);
 /* Evaluating a strex expression on a symbol table with a lookup function for variables and
  * return result as a string value. */
 
 #endif /* STREX_H */