Source file v1.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
(**************************************************************************)
(*                                                                        *)
(*  Copyright (c) 2020 OCamlPro & Origin Labs                             *)
(*                                                                        *)
(*  All rights reserved.                                                  *)
(*  This file is distributed under the terms of the GNU Lesser General    *)
(*  Public License version 2.1, with the special exception on linking     *)
(*  described in the LICENSE.md file in the root directory.               *)
(*                                                                        *)
(**************************************************************************)

module EZ_SUBST = struct

  (* TODO: add '\\' as escape character *)

  type 'context t = 'context -> string -> string

  exception UnclosedExpression of string

  let escape = ref true

  let buffer ?(sep = '$') ?(sym = false) ?(fail=true)
      ?(escape = escape) ?brace ?paren ?bracket
      ?var ~ctxt b  s =
    let len = String.length s in

    let rec iter b stack i =
      (* default state *)
      if i = len then
        match stack with
        | [] -> ()
        | (_eoi, f, b1) :: stack ->
            if fail then
              raise (UnclosedExpression (Buffer.contents b))
            else
              replace b1 f b stack i
      else
        let c = s.[i] in
        if c = sep then
          iter1 b stack (i + 1)
        else if c = '\\' && !escape then
          iter3 b stack (i + 1)
        else
          match stack with
          | [] ->
              Buffer.add_char b c;
              iter b stack (i + 1)
          | (eoi, f, b1) :: stack1 ->
              if c = eoi then
                if sym then
                  iter2 b stack eoi (i + 1)
                else
                  replace b1 f b stack1 (i + 1)
              else (
                Buffer.add_char b c;
                iter b stack (i + 1)
              )
    and iter1 b stack i =
      (* found '$' *)
      if i = len then (
        Buffer.add_char b sep;
        iter b stack i
      ) else
        let c = s.[i] in
        match (c, brace, paren, bracket, var) with
        | '{', Some f, _, _, _ ->
            iter (Buffer.create 16) (('}', f, b) :: stack) (i + 1)
        | '(', _, Some f, _, _ ->
            iter (Buffer.create 16) ((')', f, b) :: stack) (i + 1)
        | '[', _, _, Some f, _ ->
            iter (Buffer.create 16) ((']', f, b) :: stack) (i + 1)
        | ('a' .. 'z' | 'A' .. 'Z'), _, _, _, Some f ->
            let b1 = Buffer.create 16 in
            Buffer.add_char b1 c;
            iter4 b1 (('_', f, b) :: stack) (i + 1)
        | _ ->
            Buffer.add_char b sep;
            iter b stack i
    and iter2 b stack eoi i =
      (* stack<>[] & found '}', need '$' *)
      if i = len then
        if fail then
          raise (UnclosedExpression (Buffer.contents b))
        else
          match stack with
          | [] -> assert false
          | (_eoi, f, b1) :: stack ->
              replace b1 f b stack i
      else
        let c = s.[i] in
        if c = sep then
          match stack with
          | [] -> assert false
          | (_eoi, f, b1) :: stack -> replace b1 f b stack (i + 1)
        else (
          Buffer.add_char b eoi;
          iter b stack i
        )
    and iter3 b stack i =
      (* found '\\' *)
      if i = len then (
        Buffer.add_char b '\\';
        iter b stack i
      ) else (
        Buffer.add_char b s.[i];
        iter b stack (i + 1)
      )
    and iter4 b stack i =
      (* default state *)
      if i = len then
        match stack with
        | [] -> assert false
        | (_eoi, f, b1) :: stack -> replace b1 f b stack i
      else
        let c = s.[i] in
        match c with
        | 'A' .. 'Z'
        | 'a' .. 'z'
        | '_'
        | '0' .. '9' ->
            Buffer.add_char b c;
            iter4 b stack (i + 1)
        | _ -> (
            match stack with
            | [] -> assert false
            | (_eoi, f, b1) :: stack -> replace b1 f b stack i )
    and replace b1 f b stack i =
      let ident = Buffer.contents b in
      let replacement = f ctxt ident in
      Buffer.add_string b1 replacement;
      iter b1 stack i
    in

    iter b [] 0

  let string ?sep ?sym ?fail ?escape
      ?brace ?paren ?bracket ?var ~ctxt s =
    let b = Buffer.create (String.length s) in
    buffer ?sep ?sym ?escape ?fail ?brace ?paren ?bracket ?var b ~ctxt s;
    Buffer.contents b



  exception UnknownExpression of string

  let string_from_list ?sep ?sym ?(fail=true)
      ?(brace=true) ?(paren=true) ?(bracket=true) ?(var=true)
      ?default list s =
    let ctxt = default in
    let subst default s = match List.assoc s list with
      | s -> s
      | exception Not_found ->
          match default with
          | Some s -> s
          | None ->
              if fail then raise (UnknownExpression s)
              else s
    in
    let subst flag = if flag then Some subst else None in
    let brace = subst brace in
    let paren = subst paren in
    let bracket = subst bracket in
    let var = subst var in
    string ?sep ?sym ~fail ?brace ?paren ?bracket ?var ~ctxt s

end