tokenizer init

2019-06-26 22:21:36 +02:00 · 2019-06-26 22:21:36 +02:00 · 8b790839df
commit 8b790839df
1 changed files with 54 additions and 0 deletions
--- a/tokenize.l
+++ b/tokenize.l
@ -0,0 +1,54 @@
+/* 
+ *	flex tokenize.l
+ *	cc lex.yy.c -lfl
+ */
+%{
+enum yytokentype {
+  NUMBER = 258,
+  LPAR   = 259,
+  RPAR   = 260,
+  SYM    = 261,
+  STR    = 262,
+	EOL    = 263
+};
+
+int   yylval;
+char *yystr;
+%}
+
+%%
+"("	                   { return LPAR; }
+")"	                   { return RPAR; }
+[0-9]+	               { yylval = atoi(yytext); return NUMBER; }
+[ \t\n]                { /* ignore white space */ }
+\".*\"	               { printf("str: %s\n", yytext); }
+[a-zA-Z][a-zA-Z0-9]*   { printf("sym: %s\n", yytext); }
+.                      { printf("error: %s\n", yytext); }
+%%
+
+
+/*
+ * Goal: write LISP read-eval-print Loop and support
+ *       @       Function
+ *       0,1     boolean        (nand 0 1)    -> boolean
+ *                              (eq 0 0)      -> boolean
+ *       "str"   Strings        (streq str1 str2) -> boolean
+ *       abc     Symboles       (symeq s1 s2)     -> boolean
+ *       1234    Number/Integer [add,sub,div,mul,mod] -> number
+ *                              [lt, numeq]          -> boolean
+ *
+ *     (define a <symbol,number,#function)
+ *     (lambda (param ..) (.. body ..))
+ *     (if <bool> <body> <else>)
+ */
+
+int main(void)
+{
+  int tok;
+
+  while(tok = yylex()) {
+    printf("token: %d\n", tok);
+    if(tok == NUMBER) printf(" = %d\n", yylval);
+    //else printf("\n");
+  }
+}