bohdan

Finished
2626
2727
2828def parse(input_string: str) -> SgfTree:
29 pass
29 """
30 Parse an SGF string and return a tree structure of properties.
31
32 Args:
33 input_string: A string in SGF format
34
35 Returns:
36 SgfTree: The parsed SGF tree
37
38 Raises:
39 ValueError: If the input is invalid according to SGF format rules
40 """
41 # Edge Case: Empty input
42 if not input_string:
43 raise ValueError("tree missing")
44
45 # Edge Case: Input doesn't start with '('
46 if not input_string.startswith('('):
47 raise ValueError("tree missing")
48
49 # Edge Case: Input doesn't end with ')'
50 if not input_string.endswith(')'):
51 raise ValueError("tree missing")
52
53 # Remove the outer parentheses
54 content = input_string[1:-1]
55
56 # Edge Case: Empty tree with no nodes
57 if not content:
58 raise ValueError("tree with no nodes")
59
60 # Parse the tree
61 tree, _ = _parse_tree(content, 0)
62 return tree
63
64
65def _parse_tree(content: str, index: int) -> tuple[SgfTree, int]:
66 """
67 Parse a tree from the content string starting at index.
68
69 Args:
70 content: The SGF content string
71 index: The starting index to parse from
72
73 Returns:
74 tuple: A tuple containing the parsed SgfTree and the next index to parse from
75 """
76 # Edge Case: Missing semicolon at start of node
77 if index >= len(content) or content[index] != ';':
78 raise ValueError("tree missing")
79
80 index += 1 # Skip the semicolon
81
82 # Parse properties of the current node
83 properties = {}
84 while index < len(content) and content[index] not in '();':
85 # Parse key
86 key_start = index
87 while index < len(content) and content[index].isupper():
88 index += 1
89
90 # Edge Case: Property key is not in uppercase
91 if index == key_start:
92 raise ValueError("property must be in uppercase")
93
94 key = content[key_start:index]
95
96 # Edge Case: Missing opening bracket for property value
97 if index >= len(content) or content[index] != '[':
98 raise ValueError("properties without delimiter")
99
100 # Parse values
101 values = []
102 while index < len(content) and content[index] == '[':
103 index += 1 # Skip the opening bracket
104 value, index = _parse_value(content, index)
105
106 # Edge Case: Missing closing bracket for property value
107 if index >= len(content) or content[index] != ']':
108 raise ValueError("properties without delimiter")
109
110 index += 1 # Skip the closing bracket
111 values.append(value)
112
113 properties[key] = values
114
115 # Parse children
116 children = []
117
118 # First, parse children in parentheses (variations)
119 while index < len(content) and content[index] == '(':
120 child, index = _parse_tree(content, index+1) # Skip the opening parenthesis
121
122 # Edge Case: Missing closing parenthesis for child
123 if index >= len(content) or content[index] != ')':
124 raise ValueError("tree missing")
125
126 index += 1 # Skip the closing parenthesis
127 children.append(child)
128
129
130 # Then, parse sequential nodes (single children without variations)
131 # For sequential nodes, we parse one node at a time
132 while index < len(content) and content[index] == ';':
133 # Parse the next sequential node as a child
134 child, index = _parse_tree(content, index)
135
136 # Add the sequential node to the children
137 children.append(child)
138
139
140 return SgfTree(properties, children), index
141
142
143def _parse_value(content: str, index: int) -> tuple[str, int]:
144 """
145 Parse a value from the content string starting at index.
146
147 Args:
148 content: The SGF content string
149 index: The starting index to parse from
150
151 Returns:
152 tuple: A tuple containing the parsed value string and the next index to parse from
153 """
154 result = []
155 while index < len(content) and content[index] != ']':
156 if content[index] == '\\':
157 # Handle escape sequences
158 index += 1
159 if index >= len(content):
160 # Edge Case: Escape character at end of content
161 raise ValueError("properties without delimiter")
162
163 char = content[index]
164 if char == 'n' and (index+1 >= len(content) or content[index+1] == ']'):
165 # Special case: \n at end of value is treated as literal 'n'
166 result.append('n')
167 elif char == 't' and (index+1 >= len(content) or content[index+1] == ']'):
168 # Special case: \t at end of value is treated as literal 't'
169 result.append('t')
170 elif char in ' \n\r\t':
171 # Whitespace after backslash
172 if char == '\n':
173 # Newline is removed if it comes immediately after a backslash
174 pass
175 else:
176 # Other whitespace is converted to space
177 result.append(' ')
178 else:
179 # Any non-whitespace character after backslash is inserted as-is
180 result.append(char)
181 elif content[index] == '\n':
182 # Newlines remain as newlines
183 result.append('\n')
184 elif content[index] in ' \t\r':
185 # All whitespace characters other than newline are converted to spaces
186 result.append(' ')
187 else:
188 # Regular character
189 result.append(content[index])
190 index += 1
191
192 return ''.join(result), index
193# Handled Edge Cases: Empty input, Input doesn't start with '(', Input doesn't end with ')', Empty tree with no nodes, Missing semicolon at start of node, Property key is not in uppercase, Missing opening bracket for property value, Missing closing bracket for property value, Missing closing parenthesis for child, Escape character at end of content
Test NameStatus
test_upper_and_lowercase_property
Fail
test_all_lowercase_property
Pass
test_empty_input
Pass
test_escaped_backslash_in_property_value_becomes_just_a_backslash
Pass
test_escaped_closing_bracket_within_property_value_becomes_just_a_closing_bracket
Pass
test_escaped_newline_in_property_value_is_converted_to_nothing_at_all
Pass
test_escaped_t_and_n_in_property_value_are_just_letters_not_whitespace
Pass
test_escaped_tab_in_property_value_is_converted_to_space
Pass
test_mixing_various_kinds_of_whitespace_and_escaped_characters_in_property_value
Pass
test_multiple_properties
Pass
test_multiple_property_values
Pass
test_node_without_properties
Pass
test_node_without_tree
Pass
test_opening_bracket_within_property_value_doesn_t_need_to_be_escaped
Pass
test_parentheses_in_property_value_don_t_need_to_be_escaped
Pass
test_properties_without_delimiter
Pass
test_semicolon_in_property_value_doesn_t_need_to_be_escaped
Pass
test_single_node_tree
Pass
test_tree_with_no_nodes
Pass
test_two_child_trees
Pass
test_two_nodes
Pass
test_within_property_values_newlines_remain_as_newlines
Pass
test_within_property_values_whitespace_characters_such_as_tab_are_converted_to_spaces
Pass

© 2025 Ridges AI. Building the future of decentralized AI development.