1 files changed, 100 insertions, 0 deletions
diff --git a/support/rail/lex.l b/support/rail/lex.l
new file mode 100644
index 0000000000..7b61c0eb30
--- /dev/null
+++ b/support/rail/lex.l
@@ -0,0 +1,100 @@
+/* lex.l - lexical analyzer for rail program */
+
+%{
+
+#include <string.h>
+
+#include "rail.h"
+#include "gram.h"
+
+unsigned line;	/* current input line */
+int copy;	/* copy to output flag */
+
+#define	COPY	(copy && fputs(yytext,outf))
+
+extern YYSTYPE yylval;
+
+%}
+
+%%
+
+[a-zA-Z_][0-9a-zA-Z_.]* {
+		COPY;
+		yylval.id=lookup(yytext);
+		return(IDENTIFIER);
+}
+
+[0-9][0-9]* {
+		COPY;
+		yylval.num=atoi(yytext);
+		return(NUMBER);
+}
+
+\\rail@i {
+		COPY;
+		return(RAILI);
+}
+
+\\rail@p {
+		COPY;
+		return(RAILP);
+}
+
+\\rail@t {
+		COPY;
+		return(RAILT);
+}
+
+\\par {
+		COPY;
+}
+
+\\\\ {		COPY;
+		return(RAILCR);
+}
+
+\\[a-zA-Z@]+ {
+		COPY;
+		return(CS);
+}
+
+\\[^ \n\t] {
+		COPY;
+		return(CS);
+}
+
+'[^\n\t']*' {
+		COPY;
+		yytext[yyleng-1]='\0';
+		yylval.text=mcheck(strdup(yytext+1));
+		return(STRING);
+}
+
+\[[^\n\t\]]*\] {
+		COPY;
+		yytext[yyleng-1]='\0';
+		yylval.text=mcheck(strdup(yytext+1));
+		return(ANNOT);
+}
+
+\"[^\n\t\"]*\" {
+		COPY;
+		yytext[yyleng-1]='\0';
+		yylval.text=mcheck(strdup(yytext+1));
+		return(STRING);
+}
+
+[ \t]+ {
+		COPY;
+}
+
+\n {
+		COPY;
+		line++;
+}
+
+. {
+		COPY;
+		return(yytext[0]);
+}
+