Commit | Line | Data |
---|---|---|
78c9eca5 SK |
1 | { |
2 | open Tiger_parser.Token | |
3 | ||
4 | let comment_level = ref 0 | |
5 | let string_buf = Buffer.create 100 | |
6 | } | |
7 | ||
8 | let alpha = ['a'-'z' 'A'-'Z'] | |
9 | let num = ['0'-'9'] | |
10 | let newline = '\n' | '\r' | "\n\r" | |
11 | ||
12 | rule token = parse | |
13 | | eof { | |
b828a6e7 | 14 | None |
78c9eca5 SK |
15 | } |
16 | ||
17 | (* Track line number *) | |
18 | | newline { | |
19 | Lexing.new_line lexbuf; | |
20 | token lexbuf | |
21 | } | |
22 | ||
23 | (* Comment *) | |
24 | | "/*" { | |
25 | incr comment_level; | |
26 | comment lexbuf | |
27 | } | |
28 | ||
b828a6e7 SK |
29 | | ":=" {Some ASSIGN} |
30 | | "<=" {Some LE} | |
31 | | ">=" {Some GE} | |
32 | | "<>" {Some NEQ} | |
33 | | '&' {Some AND} | |
34 | | '(' {Some LPAREN} | |
35 | | ')' {Some RPAREN} | |
36 | | '*' {Some TIMES} | |
37 | | '+' {Some PLUS} | |
38 | | '-' {Some MINUS} | |
39 | | '/' {Some DIVIDE} | |
40 | | ',' {Some COMMA} | |
41 | | '.' {Some DOT} | |
42 | | ':' {Some COLON} | |
43 | | ';' {Some SEMICOLON} | |
44 | | '>' {Some GT} | |
45 | | '<' {Some LT} | |
46 | | '=' {Some EQ} | |
47 | | '[' {Some LBRACK} | |
48 | | ']' {Some RBRACK} | |
49 | | '{' {Some LBRACE} | |
50 | | '}' {Some RBRACE} | |
51 | | '|' {Some OR} | |
78c9eca5 SK |
52 | |
53 | (* String literal *) | |
54 | | '"' { | |
55 | string_literal lexbuf | |
56 | } | |
57 | ||
58 | (* Drop whitespace *) | |
59 | | [' ' '\t'] { | |
60 | token lexbuf | |
61 | } | |
62 | ||
63 | | (num+ as int) { | |
b828a6e7 | 64 | Some (INT (int_of_string int)) |
78c9eca5 SK |
65 | } |
66 | ||
67 | | (alpha (alpha | num | '_')* as id) { | |
68 | match id with | |
b828a6e7 SK |
69 | | "array" -> Some ARRAY |
70 | | "break" -> Some BREAK | |
71 | | "do" -> Some DO | |
72 | | "else" -> Some ELSE | |
73 | | "end" -> Some END | |
74 | | "for" -> Some FOR | |
75 | | "function" -> Some FUNCTION | |
76 | | "if" -> Some IF | |
77 | | "in" -> Some IN | |
78 | | "let" -> Some LET | |
79 | | "nil" -> Some NIL | |
80 | | "of" -> Some OF | |
81 | | "then" -> Some THEN | |
82 | | "to" -> Some TO | |
83 | | "type" -> Some TYPE | |
84 | | "var" -> Some VAR | |
85 | | "while" -> Some WHILE | |
86 | | _ -> Some (ID id) | |
78c9eca5 | 87 | } |
78c9eca5 SK |
88 | and string_literal = parse |
89 | (* Keep escaped quote marks as part of the string literal *) | |
90 | | '\\' '"' { | |
91 | Buffer.add_char string_buf '"'; | |
92 | string_literal lexbuf | |
93 | } | |
94 | ||
95 | | '"' { | |
96 | let string = Buffer.contents string_buf in | |
97 | Buffer.reset string_buf; | |
b828a6e7 | 98 | Some (STRING string) |
78c9eca5 SK |
99 | } |
100 | ||
101 | ||
102 | | (_ as c) { | |
103 | Buffer.add_char string_buf c; | |
104 | string_literal lexbuf | |
105 | } | |
106 | and comment = parse | |
107 | | eof { | |
108 | (* TODO: Error: unterminated comment? or we don't care? *) | |
b828a6e7 | 109 | None |
78c9eca5 SK |
110 | } |
111 | ||
112 | (* Track line number *) | |
113 | | newline { | |
114 | Lexing.new_line lexbuf; | |
115 | comment lexbuf | |
116 | } | |
117 | ||
118 | | "/*" { | |
119 | incr comment_level; | |
120 | comment lexbuf | |
121 | } | |
122 | ||
123 | | "*/" { | |
124 | decr comment_level; | |
125 | match !comment_level with | |
126 | | 0 -> token lexbuf | |
127 | | n when n > 0 -> comment lexbuf | |
128 | | _ -> assert false | |
129 | } | |
130 | ||
131 | (* Drop comment contents *) | |
132 | | _ { | |
133 | comment lexbuf | |
134 | } |