# avoid cyclic references between `append_json` and `to_json` when none are
# implemented.
protected fun to_json_by_append: String do
- var buffer = new RopeBuffer
+ var buffer = new FlatBuffer
append_json(buffer)
return buffer.to_s
end
redef class Text
super Jsonable
+ # Removes JSON-escaping if necessary in a JSON string
+ #
+ # assert "\\\"string\\uD83D\\uDE02\\\"".unescape_json == "\"string😂\""
+ fun unescape_json: Text do
+ if not json_need_escape then return self
+ return self.json_to_nit_string
+ end
+
+ # Does `self` need treatment from JSON to Nit ?
+ #
+ # i.e. is there at least one `\` character in it ?
+ #
+ # assert not "string".json_need_escape
+ # assert "\\\"string\\\"".json_need_escape
+ protected fun json_need_escape: Bool do return has('\\')
+
redef fun append_json(buffer) do
buffer.add '\"'
for i in [0 .. self.length[ do
buffer.append "\\\\"
else if char == '\"' then
buffer.append "\\\""
- else if char == '\/' then
- buffer.append "\\/"
else if char < ' ' then
if char == '\n' then
buffer.append "\\n"
buffer.append "\\r"
else if char == '\t' then
buffer.append "\\t"
- else if char == 0x0C.code_point then
- buffer.append "\\f"
- else if char == 0x08.code_point then
- buffer.append "\\b"
else
buffer.append char.escape_to_utf16
end
buffer.add '\"'
end
+ # Escapes `self` from a JSON string to a Nit string
+ #
+ # assert "\\\"string\\\"".json_to_nit_string == "\"string\""
+ # assert "\\nEscape\\t\\n".json_to_nit_string == "\nEscape\t\n"
+ # assert "\\u0041zu\\uD800\\uDFD3".json_to_nit_string == "Azu𐏓"
+ protected fun json_to_nit_string: String do
+ var res = new FlatBuffer.with_capacity(bytelen)
+ var i = 0
+ while i < self.length do
+ var char = self[i]
+ if char == '\\' then
+ i += 1
+ char = self[i]
+ if char == 'b' then
+ char = 0x08.code_point
+ else if char == 'f' then
+ char = 0x0C.code_point
+ else if char == 'n' then
+ char = '\n'
+ else if char == 'r' then
+ char = '\r'
+ else if char == 't' then
+ char = '\t'
+ else if char == 'u' then
+ var code = substring(i + 1, 4)
+ var hx = code.to_hex
+ if hx >= 0xD800 and hx <= 0xDFFF then
+ var lostr = substring(i + 7, 4)
+ if lostr.length < 4 then
+ hx = 0xFFFD
+ else
+ hx <<= 16
+ hx += lostr.to_hex
+ hx = hx.from_utf16_surr
+ end
+ i += 6
+ end
+ i += 4
+ char = hx.code_point
+ end
+ # `"`, `/` or `\` => Keep `char` as-is.
+ end
+ res.add char
+ i += 1
+ end
+ return res.to_s
+ end
+
+
# Encode `self` in JSON.
#
# ~~~
# assert "\t\"http://example.com\"\r\n\0\\".to_json ==
- # "\"\\t\\\"http:\\/\\/example.com\\\"\\r\\n\\u0000\\\\\""
+ # "\"\\t\\\"http://example.com\\\"\\r\\n\\u0000\\\\\""
# ~~~
- redef fun to_json do return to_json_by_append
+ redef fun to_json do
+ var b = new FlatBuffer.with_capacity(bytelen)
+ append_json(b)
+ return b.to_s
+ end
# Parse `self` as JSON.
#
end
end
+redef class FlatText
+ redef fun json_need_escape do
+ var its = items
+ for i in [first_byte .. last_byte] do
+ if its[i] == 0x5Cu8 then return true
+ end
+ return false
+ end
+end
+
redef class Buffer
# Append the JSON representation of `jsonable` to `self`.
redef class Nstring
# The represented string.
- private fun to_nit_string: String do
- var res = new Buffer
- var i = 1
- while i < text.length - 1 do
- var char = text[i]
- if char == '\\' then
- i += 1
- char = text[i]
- if char == 'b' then
- char = 0x08.code_point
- else if char == 'f' then
- char = 0x0C.code_point
- else if char == 'n' then
- char = '\n'
- else if char == 'r' then
- char = '\r'
- else if char == 't' then
- char = '\t'
- else if char == 'u' then
- var escape = new Buffer
- escape.append "\\u"
- var code = text.substring(i + 1, 4)
- escape.append code
- var hx = code.to_hex
- if hx >= 0xD800 and hx <= 0xDFFF then
- var lostr = text.substring(i + 7, 4)
- if lostr.length < 4 then
- escape.clear
- escape.append "\\uFFFD"
- else
- escape.append "\\u"
- escape.append lostr
- end
- i += 6
- end
- i += 4
- char = escape.from_utf16_escape
- end
- # `"`, `/` or `\` => Keep `char` as-is.
- end
- res.add char
- i += 1
- end
- return res.to_s
- end
+ private fun to_nit_string: String do return text.substring(1, text.length - 2).unescape_json.to_s
end
redef class Nvalue_object
--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Simple ad-hoc implementation of a JSON parser for String inputs
+module string_parser
+
+import parser_base
+import static
+
+redef class Char
+ # Is `self` a valid number start ?
+ private fun is_json_num_start: Bool do
+ if self == '-' then return true
+ if self.is_numeric then return true
+ return false
+ end
+
+ # Is `self` a valid JSON separator ?
+ private fun is_json_separator: Bool do
+ if self == ':' then return true
+ if self == ',' then return true
+ if self == '{' then return true
+ if self == '}' then return true
+ if self == '[' then return true
+ if self == ']' then return true
+ if self == '"' then return true
+ if self.is_whitespace then return true
+ return false
+ end
+end
+
+# A simple ad-hoc JSON parser
+#
+# To parse a simple JSON document, read it as a String and give it to `parse_entity`
+# NOTE: if your document contains several non-nested entities, use `parse_entity` for each
+# JSON entity to parse
+class JSONStringParser
+ super StringProcessor
+
+ # Parses a JSON Entity
+ #
+ # ~~~nit
+ # var p = new JSONStringParser("""{"numbers": [1,23,3], "string": "string"}""")
+ # assert p.parse_entity isa JsonObject
+ # ~~~
+ fun parse_entity: nullable Jsonable do
+ var srclen = len
+ ignore_whitespaces
+ if pos >= srclen then return make_parse_error("Empty JSON")
+ var c = src[pos]
+ if c == '[' then
+ pos += 1
+ return parse_json_array
+ else if c == '"' then
+ var s = parse_json_string
+ return s
+ else if c == '{' then
+ pos += 1
+ return parse_json_object
+ else if c == 'f' then
+ if pos + 4 >= srclen then make_parse_error("Error: bad JSON entity")
+ if src[pos + 1] == 'a' and src[pos + 2] == 'l' and src[pos + 3] == 's' and src[pos + 4] == 'e' then
+ pos += 5
+ return false
+ end
+ return make_parse_error("Error: bad JSON entity")
+ else if c == 't' then
+ if pos + 3 >= srclen then make_parse_error("Error: bad JSON entity")
+ if src[pos + 1] == 'r' and src[pos + 2] == 'u' and src[pos + 3] == 'e' then
+ pos += 4
+ return true
+ end
+ return make_parse_error("Error: bad JSON entity")
+ else if c == 'n' then
+ if pos + 3 >= srclen then make_parse_error("Error: bad JSON entity")
+ if src[pos + 1] == 'u' and src[pos + 2] == 'l' and src[pos + 3] == 'l' then
+ pos += 4
+ return null
+ end
+ return make_parse_error("Error: bad JSON entity")
+ end
+ if not c.is_json_num_start then return make_parse_error("Bad JSON character")
+ return parse_json_number
+ end
+
+ # Parses a JSON Array
+ fun parse_json_array: Jsonable do
+ var max = len
+ if pos >= max then return make_parse_error("Incomplete JSON array")
+ var arr = new JsonArray
+ var c = src[pos]
+ while not c == ']' do
+ ignore_whitespaces
+ if pos >= max then return make_parse_error("Incomplete JSON array")
+ if src[pos] == ']' then break
+ var ent = parse_entity
+ #print "Parsed an entity {ent} for a JSON array"
+ if ent isa JsonParseError then return ent
+ arr.add ent
+ ignore_whitespaces
+ if pos >= max then return make_parse_error("Incomplete JSON array")
+ c = src[pos]
+ if c == ']' then break
+ if c != ',' then return make_parse_error("Bad array separator {c}")
+ pos += 1
+ end
+ pos += 1
+ return arr
+ end
+
+ # Parses a JSON Object
+ fun parse_json_object: Jsonable do
+ var max = len
+ if pos >= max then return make_parse_error("Incomplete JSON object")
+ var obj = new JsonObject
+ var c = src[pos]
+ while not c == '}' do
+ ignore_whitespaces
+ if pos >= max then return make_parse_error("Malformed JSON object")
+ if src[pos] == '}' then break
+ var key = parse_entity
+ #print "Parsed key {key} for JSON object"
+ if not key isa String then return make_parse_error("Bad key format {key or else "null"}")
+ ignore_whitespaces
+ if pos >= max then return make_parse_error("Incomplete JSON object")
+ if not src[pos] == ':' then return make_parse_error("Bad key/value separator {src[pos]}")
+ pos += 1
+ ignore_whitespaces
+ var value = parse_entity
+ #print "Parsed value {value} for JSON object"
+ if value isa JsonParseError then return value
+ obj[key] = value
+ ignore_whitespaces
+ if pos >= max then return make_parse_error("Incomplete JSON object")
+ c = src[pos]
+ if c == '}' then break
+ if c != ',' then return make_parse_error("Bad object separator {src[pos]}")
+ pos += 1
+ end
+ pos += 1
+ return obj
+ end
+
+ # Creates a `JsonParseError` with the right message and location
+ protected fun make_parse_error(message: String): JsonParseError do
+ var err = new JsonParseError(message)
+ err.location = hot_location
+ return err
+ end
+
+ # Parses an Int or Float
+ fun parse_json_number: Jsonable do
+ var max = len
+ var p = pos
+ var c = src[p]
+ var is_neg = false
+ if c == '-' then
+ is_neg = true
+ p += 1
+ if p >= max then return make_parse_error("Bad JSON number")
+ c = src[p]
+ end
+ var val = 0
+ while c.is_numeric do
+ val *= 10
+ val += c.to_i
+ p += 1
+ if p >= max then break
+ c = src[p]
+ end
+ if c == '.' then
+ p += 1
+ if p >= max then return make_parse_error("Bad JSON number")
+ c = src[p]
+ var fl = val.to_f
+ var frac = 0.1
+ while c.is_numeric do
+ fl += c.to_i.to_f * frac
+ frac /= 10.0
+ p += 1
+ if p >= max then break
+ c = src[p]
+ end
+ if c == 'e' or c == 'E' then
+ p += 1
+ var exp = 0
+ if p >= max then return make_parse_error("Malformed JSON number")
+ c = src[p]
+ while c.is_numeric do
+ exp *= 10
+ exp += c.to_i
+ p += 1
+ if p >= max then break
+ c = src[p]
+ end
+ fl *= (10 ** exp).to_f
+ end
+ if p < max and not c.is_json_separator then return make_parse_error("Malformed JSON number")
+ pos = p
+ if is_neg then return -fl
+ return fl
+ end
+ if c == 'e' or c == 'E' then
+ p += 1
+ if p >= max then return make_parse_error("Bad JSON number")
+ var exp = src[p].to_i
+ c = src[p]
+ while c.is_numeric do
+ exp *= 10
+ exp += c.to_i
+ p += 1
+ if p >= max then break
+ c = src[p]
+ end
+ val *= (10 ** exp)
+ end
+ if p < max and not src[p].is_json_separator then return make_parse_error("Malformed JSON number")
+ pos = p
+ if is_neg then return -val
+ return val
+ end
+
+ # Parses and returns a Nit string from a JSON String
+ fun parse_json_string: Jsonable do
+ var ln = src.length
+ var p = pos
+ p += 1
+ if p > ln then return make_parse_error("Malformed JSON String")
+ var c = src[p]
+ var st = p
+ while c != '"' do
+ if c == '\\' then
+ if p + 1 >= ln then return make_parse_error("Malformed Escape sequence in JSON string")
+ p += 1
+ c = src[p]
+ if c == 'u' then
+ p += 1
+ if p + 3 >= ln then return make_parse_error("Bad Unicode escape sequence in string")
+ for i in [0 .. 4[ do if not src[p + i].is_hexdigit then return make_parse_error("Bad Unicode escape sequence in string")
+ p += 3
+ end
+ end
+ p += 1
+ if p >= ln then return make_parse_error("Malformed JSON String")
+ c = src[p]
+ end
+ pos = p + 1
+ return src.substring(st, p - st).unescape_json
+ end
+
+ # Ignores any character until a JSON separator is encountered
+ fun ignore_until_separator do
+ var max = len
+ while pos < max do
+ if not src[pos].is_json_separator then return
+ end
+ end
+end
+
+redef class Text
+ redef fun parse_json do return (new JSONStringParser(self.to_s)).parse_entity
+end
+
+redef class JsonParseError
+
+ # Location of the error in source
+ var location: nullable Location = null
+
+ # Get the JSON representation of `self`.
+ #
+ # ~~~
+ # var err = new JsonParseError("foo", new Position(1, 2, 3, 4, 5, 6))
+ # assert err.to_json == "Parsing error: foo"
+ # ~~~
+ redef fun to_json do
+ var l = location
+ var m = message
+ return if l == null then "Parsing error: {m}" else "Parsing error at {l}: {m}"
+ end
+
+ redef fun to_s do return to_json
+end
# Basic facilities for common parser operations on String sources
class StringProcessor
# Source document to parse
- private var src: String
+ protected var src: String
+
+ # Length of the source document
+ protected var len: Int is noinit
# Current position in `src`
- private var pos = 0
+ protected var pos = 0
# Position at which current line started
- private var line_start = 0
+ protected var line_start = 0
# Current line in `src`
- private var line = 1
+ protected var line = 1
# Offset in the current line
- private fun line_offset: Int do return pos - line_start + 1
+ protected fun line_offset: Int do return pos - line_start + 1
+
+ init do
+ _len = src.length
+ end
# Gives the current location in the `src`
fun current_location: Location do return new Location(line, line_offset)
# Advances in `src` until a non-whitespace character is encountered
- private fun ignore_whitespaces do
- var srclen = src.length
- if pos >= srclen then return
- var c = src[pos]
+ protected fun ignore_whitespaces do
+ var srclen = _len
+ var p = _pos
+ if p >= srclen then return
+ var c = src[p]
while c.is_whitespace do
- pos += 1
- if pos >= srclen then break
+ p += 1
+ if p >= srclen then break
if c == '\n' then
- line += 1
- line_start = pos
+ _line += 1
+ _line_start = p
end
- c = src[pos]
+ c = src[p]
end
+ _pos = p
+ return
end
# Reads characters until pattern `s` is found
- private fun ignore_until(s: String): Int do
- if s.length == 0 then return pos
- var srclen = src.length
- if pos >= srclen then return -1
+ protected fun ignore_until(s: String): Int do
+ if s.length == 0 then return _pos
+ var srclen = _len
+ var p = _pos
+ if p >= srclen then return -1
loop
var c = s[0]
- var src_c = src[pos]
+ var src_c = src[p]
while src_c != c do
- pos += 1
- if pos >= srclen then return -1
+ p += 1
+ if p >= srclen then
+ _pos = p
+ return -1
+ end
if src_c == '\n' then
line += 1
line_start= pos
end
- src_c = src[pos]
+ src_c = src[p]
end
- var relpos = pos
+ var relpos = p
var fnd = true
for i in s do
if relpos >= srclen then
break
end
if src[relpos] != i then
- pos += 1
+ p += 1
fnd = false
break
end
relpos += 1
end
- if fnd then return pos
+ if fnd then
+ _pos = p
+ return p
+ end
end
end
+
+ # Ignores any printable character until a whitespace is encountered
+ protected fun ignore_until_whitespace: Int do
+ while not src[pos].is_whitespace do pos += 1
+ return pos
+ end
+
+ # Returns the current location as a `Location` object
+ protected fun hot_location: Location do return new Location(line, line_offset)
end
# Information about the location of an entity in a source document
nitlanguage / nit.git / commitdiff