1 files changed, 47 insertions, 0 deletions
diff --git a/src/lexer.l b/src/lexer.l
new file mode 100644
index 0000000..c9aaff0
--- /dev/null
+++ b/src/lexer.l
@@ -0,0 +1,47 @@
+%option noyywrap yylineno
+
+%{
+#include "parser.tab.h"
+%}
+
+DIGIT       [0-9]
+IDENT       [A-Za-z][A-Za-z0-9]*
+WHITESPACE  [ \t\r\n]+
+
+%%
+
+"skip"          { return TOKEN_SKIP; }
+"if"            { return TOKEN_IF; }
+"then"          { return TOKEN_THEN; }
+"else"          { return TOKEN_ELSE; }
+"end"           { return TOKEN_END; }
+"while"         { return TOKEN_WHILE; }
+"do"            { return TOKEN_DO; }
+
+"("             { return TOKEN_LEFT_PARENTHESIS; }
+")"             { return TOKEN_RIGHT_PARENTHESIS; }
+";"             { return TOKEN_SEMICOLON; }
+":="            { return TOKEN_ASSIGN; }
+
+"+"             { return TOKEN_PLUS; }
+"-"             { return TOKEN_MINUS; }
+"*"             { return TOKEN_MULTIPLY; }
+
+"or"            { return TOKEN_OR; }
+"and"           { return TOKEN_AND; }
+"not"           { return TOKEN_NOT; }
+
+"="             { return TOKEN_EQUALS; }
+"#"             { return TOKEN_NOT_EQUALS; }
+"<="            { return TOKEN_LESS_EQUAL; }
+"<"             { return TOKEN_LESS_THAN; }
+">="            { return TOKEN_GREATER_EQUAL; }
+">"             { return TOKEN_GREATER_THAN; }
+
+{DIGIT}+        { yylval.num = atoi(yytext); return TOKEN_NUMERAL; }
+{IDENT}         { yylval.id = strdup(yytext); return TOKEN_IDENTIFIER; }
+
+{WHITESPACE}    { }
+.               { fprintf(stderr, "Unknown char: %s\n", yytext); }
+
+%%