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-rw-r--r--edify/expr.h65
1 files changed, 50 insertions, 15 deletions
diff --git a/edify/expr.h b/edify/expr.h
index d2e739201..1462531b0 100644
--- a/edify/expr.h
+++ b/edify/expr.h
@@ -39,8 +39,17 @@ typedef struct {
char* errmsg;
} State;
-typedef char* (*Function)(const char* name, State* state,
- int argc, Expr* argv[]);
+#define VAL_STRING 1 // data will be NULL-terminated; size doesn't count null
+#define VAL_BLOB 2
+
+typedef struct {
+ int type;
+ ssize_t size;
+ char* data;
+} Value;
+
+typedef Value* (*Function)(const char* name, State* state,
+ int argc, Expr* argv[]);
struct Expr {
Function fn;
@@ -50,31 +59,41 @@ struct Expr {
int start, end;
};
+// Take one of the Expr*s passed to the function as an argument,
+// evaluate it, return the resulting Value. The caller takes
+// ownership of the returned Value.
+Value* EvaluateValue(State* state, Expr* expr);
+
+// Take one of the Expr*s passed to the function as an argument,
+// evaluate it, assert that it is a string, and return the resulting
+// char*. The caller takes ownership of the returned char*. This is
+// a convenience function for older functions that want to deal only
+// with strings.
char* Evaluate(State* state, Expr* expr);
// Glue to make an Expr out of a literal.
-char* Literal(const char* name, State* state, int argc, Expr* argv[]);
+Value* Literal(const char* name, State* state, int argc, Expr* argv[]);
// Functions corresponding to various syntactic sugar operators.
// ("concat" is also available as a builtin function, to concatenate
// more than two strings.)
-char* ConcatFn(const char* name, State* state, int argc, Expr* argv[]);
-char* LogicalAndFn(const char* name, State* state, int argc, Expr* argv[]);
-char* LogicalOrFn(const char* name, State* state, int argc, Expr* argv[]);
-char* LogicalNotFn(const char* name, State* state, int argc, Expr* argv[]);
-char* SubstringFn(const char* name, State* state, int argc, Expr* argv[]);
-char* EqualityFn(const char* name, State* state, int argc, Expr* argv[]);
-char* InequalityFn(const char* name, State* state, int argc, Expr* argv[]);
-char* SequenceFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* ConcatFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* LogicalAndFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* LogicalOrFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* LogicalNotFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* SubstringFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* EqualityFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* InequalityFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* SequenceFn(const char* name, State* state, int argc, Expr* argv[]);
// Convenience function for building expressions with a fixed number
// of arguments.
Expr* Build(Function fn, YYLTYPE loc, int count, ...);
// Global builtins, registered by RegisterBuiltins().
-char* IfElseFn(const char* name, State* state, int argc, Expr* argv[]);
-char* AssertFn(const char* name, State* state, int argc, Expr* argv[]);
-char* AbortFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* IfElseFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* AssertFn(const char* name, State* state, int argc, Expr* argv[]);
+Value* AbortFn(const char* name, State* state, int argc, Expr* argv[]);
// For setting and getting the global error string (when returning
@@ -112,15 +131,31 @@ Function FindFunction(const char* name);
// to NULL, free the rest and return -1. Return 0 on success.
int ReadArgs(State* state, Expr* argv[], int count, ...);
+// Evaluate the expressions in argv, giving 'count' Value* (the ... is
+// zero or more Value** to put them in). If any expression evaluates
+// to NULL, free the rest and return -1. Return 0 on success.
+int ReadValueArgs(State* state, Expr* argv[], int count, ...);
+
// Evaluate the expressions in argv, returning an array of char*
// results. If any evaluate to NULL, free the rest and return NULL.
// The caller is responsible for freeing the returned array and the
// strings it contains.
char** ReadVarArgs(State* state, int argc, Expr* argv[]);
+// Evaluate the expressions in argv, returning an array of Value*
+// results. If any evaluate to NULL, free the rest and return NULL.
+// The caller is responsible for freeing the returned array and the
+// Values it contains.
+Value** ReadValueVarArgs(State* state, int argc, Expr* argv[]);
+
// Use printf-style arguments to compose an error message to put into
// *state. Returns NULL.
-char* ErrorAbort(State* state, char* format, ...);
+Value* ErrorAbort(State* state, char* format, ...);
+
+// Wrap a string into a Value, taking ownership of the string.
+Value* StringValue(char* str);
+// Free a Value object.
+void FreeValue(Value* v);
#endif // _EXPRESSION_H