refactor(bones)!: rename nivis-python -> nivis_python

1 files changed, 145 insertions, 0 deletions

diff --git a/nivis_python/parsers.py b/nivis_python/parsers.py
new file mode 100644
index 0000000..ca004f7
--- /dev/null
+++ b/nivis_python/parsers.py
@@ -0,0 +1,145 @@
+from .lexer import Lexer, Token
+
+
+__all__ = ["Parser"]
+
+
+class Parser:
+    """
+    A class representing a parser for Psi code.
+
+    Args:
+        input: The input code to be parsed.
+
+    Returns:
+        None
+
+    Example:
+        ```python
+        parser = Parser(input)
+        parser.parse()
+        ```
+    """
+
+    def __init__(self, input):
+        """
+        Initializes a Parser object.
+
+        Args:
+            input: The input code to be parsed.
+
+        Returns:
+            None
+        """
+        self.lexer = Lexer(input)
+        self.tokens = iter(self.lexer)
+        self.current_token = next(self.tokens)
+
+    def parse(self):
+        """
+        Parses the input code.
+
+        Returns:
+            The result of the parsing.
+        """
+        return self.parse_expr()
+
+    def parse_expr(self):
+        """
+        Parses an expression in the input code.
+
+        Returns:
+            The result of the parsing.
+        """
+        token = self.current_token
+        if token.value == "?":
+            self.eat("?")
+
+            condition = self.parse_condition()
+
+            self.eat(":")
+
+            if condition:
+                result = self.parse_reply()
+            else:
+                result = None
+
+            return result
+
+    def parse_condition(self):
+        """
+        Parses a condition in the input code.
+
+        Returns:
+            The result of the parsing.
+        """
+        variable = self.parse_variable()
+        self.eat("==")
+        value = self.parse_value()
+
+        return variable == value
+
+    def parse_variable(self):
+        """
+        Parses a variable in the input code.
+
+        Returns:
+            The result of the parsing.
+        """
+        token = self.current_token
+        self.eat("IDENTIFIER")
+        return token.value
+
+    def parse_value(self):
+        """
+        Parses a value in the input code.
+
+        Returns:
+            The result of the parsing.
+
+        Raises:
+            Exception: Raised when an invalid value is encountered.
+        """
+        token = self.current_token
+        if token.type == "INTEGER":
+            self.eat("INTEGER")
+            return token.value
+        else:
+            raise Exception(f"Invalid value: {token.value}")
+
+    def parse_reply(self):
+        """
+        Parses a reply in the input code.
+
+        Returns:
+            The result of the parsing.
+
+        Raises:
+            Exception: Raised when an invalid reply is encountered.
+        """
+        self.eat("reply")
+        self.eat(":")
+
+        token = self.current_token
+        if token.type != "SEPARATOR":
+            raise Exception(f"Invalid reply: {token.value}")
+
+        return token.value
+
+    def eat(self, expected_type):
+        """
+        Consumes the current token if it matches the expected type.
+
+        Args:
+            expected_type: The expected type of the token.
+
+        Returns:
+            None
+
+        Raises:
+            Exception: Raised when an unexpected token is encountered.
+        """
+        if self.current_token.type == expected_type:
+            self.current_token = next(self.tokens)
+        else:
+            raise Exception(f"Unexpected token: {self.current_token.value}")