pyfcstm.dsl.parse

Grammar parsing utilities for the pyfcstm domain-specific language.

This module provides helper functions for parsing grammar-based input text using ANTLR4-generated lexer/parser classes and a parse-tree listener that converts ANTLR parse trees into internal node objects. It centralizes the parsing workflow for different grammar entry points and exposes convenience functions for parsing common DSL constructs such as conditions, preamble programs, and operation programs.

The module contains the following main components:

parse_with_grammar_entry() - Parse text using an arbitrary grammar entry rule.
parse_condition() - Parse a condition expression.
parse_state_machine_dsl() - Parse a complete state machine DSL document.
parse_preamble() - Parse a preamble program.
parse_operation() - Parse an operation program.

Note

All parsing relies on the ANTLR4-generated classes from pyfcstm.dsl.grammar and may raise pyfcstm.dsl.error.GrammarParseError when input does not conform to the grammar.

Example:

>>> from pyfcstm.dsl.parse import parse_condition, parse_preamble
>>> condition = parse_condition("x > 5 && y < 10")
>>> preamble = parse_preamble("x := 10;")

parse_with_grammar_entry

pyfcstm.dsl.parse.parse_with_grammar_entry(input_text: str, entry_name: str, force_finished: bool = True) → Any[source]

Parse input text using a specified grammar entry point.

This function looks up a parser method on GrammarParser by name and parses the provided input text using that rule.

Parameters:

input_text (str) – The text to parse.
entry_name (str) – Name of the grammar rule to use as the entry point.
force_finished (bool, optional) – Whether to enforce that parsing consumed all input, defaults to True.

Returns:

Parsed node for the grammar entry.

Return type:

Any

Raises:

AttributeError – If entry_name does not exist on GrammarParser.
pyfcstm.dsl.error.GrammarParseError – If parsing fails or input is left unparsed when force_finished is True.

Example:

>>> result = parse_with_grammar_entry("x > 5", "condition")

parse_condition

pyfcstm.dsl.parse.parse_condition(input_text: str) → Any[source]

Parse input text as a condition expression.

This function uses the grammar’s condition rule as the entry point.

Parameters:: input_text (str) – The condition expression to parse.
Returns:: Parsed condition node.
Return type:: Any
Raises:: pyfcstm.dsl.error.GrammarParseError – If parsing fails.

Example:

>>> condition_node = parse_condition("x > 5 && y < 10")

parse_state_machine_dsl

pyfcstm.dsl.parse.parse_state_machine_dsl(input_text: str) → StateMachineDSLProgram[source]

Parse input text as a complete state machine DSL document.

This helper uses the grammar’s state_machine_dsl rule and returns a pure DSL AST.

Parameters:: input_text (str) – The state machine DSL text to parse.
Returns:: Parsed state machine DSL program node.
Return type:: StateMachineDSLProgram
Raises:: pyfcstm.dsl.error.GrammarParseError – If parsing fails.

Example:

>>> program = parse_state_machine_dsl("state Root;")
>>> program.root_state.name
'Root'

parse_preamble

pyfcstm.dsl.parse.parse_preamble(input_text: str) → Any[source]

Parse input text as a preamble program.

This function uses the grammar’s preamble_program rule as the entry point.

Parameters:: input_text (str) – The preamble program text to parse.
Returns:: Parsed preamble program node.
Return type:: Any
Raises:: pyfcstm.dsl.error.GrammarParseError – If parsing fails.

Example:

>>> preamble_node = parse_preamble("x := 10;")

parse_operation

pyfcstm.dsl.parse.parse_operation(input_text: str) → Any[source]

Parse input text as an operation program.

This function uses the grammar’s operation_program rule as the entry point.

Parameters:: input_text (str) – The operation program text to parse.
Returns:: Parsed operation program node.
Return type:: Any
Raises:: pyfcstm.dsl.error.GrammarParseError – If parsing fails.

Example:

>>> operation_node = parse_operation("x := 10;")