1 files changed, 58 insertions, 0 deletions
diff --git a/lex-pattern.l b/lex-pattern.l
new file mode 100644
index 0000000..d091c74
--- /dev/null
+++ b/lex-pattern.l
@@ -0,0 +1,58 @@
+%{
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include "ast.h"
+#include "parse-pattern.h"
+
+static int intlit(long *out, const char *in)
+{
+	errno = 0;
+	*out = strtol(in, NULL, 10);
+	return errno == ERANGE ? T_BADLIT : T_INTEGER;
+}
+
+static int strlit(char **out, const char *in, size_t inlen)
+{
+	in    += 1;
+	inlen -= 2;
+
+	size_t len = 0;
+	for (const char *c = in; c < in + inlen; c++, len++) {
+		if (*c == '\"') c++;
+	}
+
+	char *str;
+	if (!(*out = str = malloc(len + 1))) return T_NOMEM;
+
+	for (const char *c = in; c < in + inlen; *str++ = *c++) {
+		if (*c == '\"') c++;
+	}
+	*str = 0;
+
+	return T_STRING;
+}
+
+%}
+
+%option outfile="lex-pattern.c" header-file="lex-pattern.h"
+%option noyywrap never-interactive
+
+%%
+
+\(               { return T_LPAREN;      }
+\)               { return T_RPAREN;      }
+,                { return T_COMMA;       }
+\.               { return T_PERIOD;      }
+A                { return T_ALPHABETIC;  }
+N                { return T_NUMERIC;     }
+U                { return T_UPPERCASE;   }
+L                { return T_LOWERCASE;   }
+C                { return T_CONTROL;     }
+P                { return T_PUNCTUATION; }
+E                { return T_EVERYTHING;  }
+[0-9]+           { return intlit(&yylval.lval, yytext); }
+\"(\"\"|[^"])*\" { return strlit(&yylval.sval, yytext, yyleng); }
+
+%%