stage 4 (incomplete).front

1 files changed, 31 insertions, 0 deletions

diff --git a/s4/sym.c b/s4/sym.c
new file mode 100644
index 0000000..8749791
--- /dev/null
+++ b/s4/sym.c
@@ -0,0 +1,31 @@
+#include <u.h>
+#include <libc.h>
+#include "dat.h"
+#include "fns.h"
+
+static Symbol *symtab;
+
+Symbol *
+install(char *s, int t, double v)
+{
+	Symbol *sym;
+
+	sym = emalloc(sizeof(Symbol));
+	sym->name = strdup(s);
+	sym->type = t;
+	sym->u.val = v;
+	sym->next = symtab;
+	symtab = sym;
+	return sym;
+}
+
+Symbol *
+lookup(char *s)
+{
+	Symbol *sym;
+
+	for(sym = symtab; sym != nil; sym = sym->next)
+		if(strcmp(sym->name, s) == 0)
+			return sym;
+	return nil;
+}