init

tests/json.py

@@ -0,0 +1,86 @@
+from os.path import dirname
+import sys
+
+sys.path.append(f"{dirname(__file__)}/../src")
+from party import regex, Parser, just, FwDeclaration
+
+from typing import TypeVar, Any
+
+# Utilities
+# whitespace = regex(r"\s*")
+whitespace = just(" ").or_else(just("\n")).repeat()
+
+T = TypeVar("T")
+
+
+def lexeme(p: Parser[T]) -> Parser[T]:
+    return p << whitespace
+
+
+# Punctuation
+lbrace = lexeme(just("{"))
+rbrace = lexeme(just("}"))
+lbrack = lexeme(just("["))
+rbrack = lexeme(just("]"))
+colon = lexeme(just(":"))
+comma = lexeme(just(","))
+
+# Primitives
+true = lexeme(just("true")).value(True)
+false = lexeme(just("false")).value(False)
+null = lexeme(just("null")).value(None)
+number = lexeme(regex(r"-?(0|[1-9][0-9]*)([.][0-9]+)?([eE][+-]?[0-9]+)?")).map(float)
+just_part = regex(r'[^"\\]+')
+just_esc = just("\\") >> (
+    just("\\")
+    | just("/")
+    | just('"')
+    | just("b").value("\b")
+    | just("f").value("\f")
+    | just("n").value("\n")
+    | just("r").value("\r")
+    | just("t").value("\t")
+    | regex(r"u[0-9a-fA-F]{4}").map(lambda s: chr(int(s[1:], 16)))
+)
+quoted = lexeme(just('"') >> (just_part | just_esc).repeat().map(lambda l: "".join(l)) << just('"'))
+
+# Data structures
+json_value = FwDeclaration[Any]()
+object_pair = (quoted << colon) & json_value.p()
+json_object = lbrace >> object_pair.sep_by(comma).map(dict) << rbrace
+array = lbrack >> json_value.p().sep_by(comma) << rbrack
+
+# Everything
+json_value.define(quoted | number | json_object | array | true | false | null)
+json_doc = whitespace >> json_value.p()
+
+
+def test():
+    assert (
+        json_doc.parse(
+            r"""
+    {
+        "int": 1,
+        "just": "hello",
+        "a list": [1, 2, 3],
+        "escapes": "\n \u24D2",
+        "nested": {"x": "y"},
+        "other": [true, false, null]
+    }
+"""
+        )
+        == {
+            "int": 1,
+            "just": "hello",
+            "a list": [1, 2, 3],
+            "escapes": "\n ⓒ",
+            "nested": {"x": "y"},
+            "other": [True, False, None],
+        }
+    )
+
+
+if __name__ == "__main__":
+    from sys import stdin
+    test()
+    # print(repr(json_doc.parse(stdin.read())))