init

expr.h

@@ -0,0 +1,42 @@
+#ifndef __EXPR_H__
+#define __EXPR_H__
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct {
+	size_t start, end;
+	const char *err;
+} ExprError;
+
+typedef struct {
+	const char *name;
+	const char *description;
+	double (*func)(double *args);
+	const char **arg_names;
+	size_t n_args;
+} ExprBuiltinFunc;
+
+typedef struct {
+	const char *name;
+	const char *description;
+	double val;
+} ExprBuiltinVar;
+
+typedef struct _Expr Expr;
+
+extern ExprBuiltinFunc *expr_builtin_funcs;
+extern const size_t     expr_n_builtin_funcs;
+extern ExprBuiltinVar  *expr_builtin_vars;
+extern const size_t     expr_n_builtin_vars;
+
+Expr *expr_new();
+void expr_destroy(Expr *e);
+ExprError expr_set(Expr *e, const char *expr) __attribute__((warn_unused_result));
+ExprError expr_eval(Expr *e, double *out_res) __attribute__((warn_unused_result));
+void expr_set_var(Expr *e, const char *name, double val);
+bool expr_get_var(Expr *e, const char *name, double *out); /* Returns false if not present */
+void expr_set_func(Expr *e, const char *name, double (*func)(double *args), size_t n_args);
+
+#endif /* __EXPR_H__ */