1 files changed, 101 insertions, 0 deletions
diff --git a/sem3/osc/mm10/opg4.l b/sem3/osc/mm10/opg4.l
new file mode 100644
index 0000000..aeb73b1
--- /dev/null
+++ b/sem3/osc/mm10/opg4.l
@@ -0,0 +1,101 @@
+%{
+
+#include <stdio.h>
+#include <stdint.h>
+
+#define BEGIN_T 1
+#define END_T 2
+#define NUM_T 3
+#define VAR_T 4
+#define HASHSIZE 100
+
+typedef struct symnode_struct {
+	struct symnode_struct *next;
+	char *name;
+} symnode_t;
+
+symnode_t *sym_insert(char *var);
+symnode_t *sym_lookup(char *var);
+
+%}
+
+VAR			[a-zA-Z][a-zA-Z\_\-0-9]*
+TAL			[0-9]+
+
+%%
+
+begin		{printf("Found a BEGIN\n"); return BEGIN_T;}
+end			{printf("Found a END\n"); return END_T;}
+{VAR}		{printf("Found a variable %s\n", yytext); 
+				if( !sym_lookup(yytext) ) { 
+					printf("Not found inserting\n");
+					sym_insert(yytext);
+				}
+				return VAR_T;}
+{TAL}		{printf("Found a number %d\n", strtol(yytext, NULL, 10)); return NUM_T;}
+
+%%
+
+symnode_t *symlist[HASHSIZE];
+
+unsigned int hash(char *s) {
+	uint32_t hv = 0;
+	for( int i = 0; s[i] != '\0'; i++ ) {
+		// take MSB 6 bits of hv and xors with LSB of s[i]
+		uint32_t v = ( hv >> 26 ) ^ (s[i] & 0x3f);
+
+		// Push those back on hv
+		hv = (hv << 4) | v;
+	}
+	// Return appropriate size
+	return hv % HASHSIZE;
+}
+
+
+symnode_t *sym_insert(char *var) {
+	unsigned int index = hash(var);
+
+	// Save old value
+	symnode_t *oldSym = symlist[index];
+
+	// Make new
+	symlist[index] = malloc(sizeof(symnode_t));
+	if( symlist[index] == NULL ) {
+		// If malloc failed
+		symlist[index] = oldSym;
+		return NULL;
+	}
+
+	// Link old one
+	symlist[index]->next = oldSym;
+	symlist[index]->name = var;
+
+	return symlist[index];
+}
+
+symnode_t *sym_lookup(char *var) {
+	unsigned int index = hash(var);
+	symnode_t *n = symlist[index];
+
+	// Look trough list
+	while(n != NULL && strcmp(n->name, var) != 0) {
+		n = n->next;
+	}
+
+	return n;
+}
+
+
+int main(void) {
+
+	for(;;) {
+		int t = yylex();
+		printf("yylex: %d\n", t);
+		if( t == END_T ) {
+			break;
+		}
+	}
+
+	return 0;
+	
+}