feat(lexer): default grammar

1 files changed, 19 insertions, 0 deletions

diff --git a/src/elixir_math_parser_lexer.xrl b/src/elixir_math_parser_lexer.xrl
new file mode 100644
index 0000000..a2980c8
--- /dev/null
+++ b/src/elixir_math_parser_lexer.xrl
@@ -0,0 +1,19 @@
+Definitions.
+INT        = [0-9]+
+NAME       = :[a-zA-Z_][a-zA-Z0-9_]*
+WHITESPACE = [\s\t\n\r]|;{2}
+
+Rules.
+\+            : {token, {'+',  TokenLine}}.
+\-            : {token, {'-',  TokenLine}}.
+\*            : {token, {'*',  TokenLine}}.
+\/            : {token, {'/',  TokenLine}}.
+\=            : {token, {'=',  TokenLine}}.
+{NAME}        : {token, {atom, TokenLine, to_atom(TokenChars)}}.
+{INT}         : {token, {int,  TokenLine, TokenChars}}.
+{WHITESPACE}+ : skip_token.
+
+Erlang code.
+% Given a ":name", chop off : and return name as an atom.
+to_atom([$:|Chars]) ->
+    list_to_atom(Chars).