Major psql overhaul by Peter Eisentraut.

src/bin/psql/variables.h

@@ -0,0 +1,33 @@
+/* This implements a sort of variable repository. One could also think of it
+ * as cheap version of an associative array. In each one of these
+ * datastructures you can store name/value pairs.
+ *
+ * All functions (should) follow the Shit-In-Shit-Out (SISO) principle, i.e.,
+ * you can pass them NULL pointers and the like and they will return something
+ * appropriate.
+ */
+
+#ifndef VARIABLES_H
+#define VARIABLES_H
+#include <c.h>
+
+#define VALID_VARIABLE_CHARS "abcdefghijklmnopqrstuvwxyz0123456789_"
+
+struct _variable {
+    char * name;
+    char * value;
+    struct _variable * next;
+};
+
+typedef struct _variable * VariableSpace;
+
+
+VariableSpace CreateVariableSpace(void);
+const char * GetVariable(VariableSpace space, const char * name);
+bool GetVariableBool(VariableSpace space, const char * name);
+bool SetVariable(VariableSpace space, const char * name, const char * value);
+bool DeleteVariable(VariableSpace space, const char * name);
+void DestroyVariableSpace(VariableSpace space);
+
+
+#endif /* VARIABLES_H */