Parser (package)

The package represents parsing functionality of Splicer and contains following classes:

TM1RuleParser - implements custom actions that get called from the generated parser to create object tree representing parsed TM1 rule.
ArgumentParser - implements CLI parsing and is used by Splicer.py to run required actions by instantiating TM1SpliceExecutor and running its method corresponding to the action required from CLI.

TM1RuleParser (class in TM1RuleParser.py)

This class is responsible to translate parsed rule into objects in memory that represent the parsed syntax. Methods with name starting with make_ or add_match custom actions as defined in TM1RuleGrammar.peg (described later). These methods are called during parsing of the TM1 rule and are fed with data from the parser defined in TM1RuleGrammar.py.

Let’s explain how the parser stores the parsed rule in memory on following example.

Note: The below code is a simplified rule content to demonstrate parsing and resulting representation in memory, it doesn’t represent a functional rule.

SKIPCHECK;
FEEDSTRINGS;
#Expand-Area-Definition(ACT_YEARS, id_ACT_YEARS):'T Year':@mdx

#Region ACT_YEARS
[ 'T Month':'T Month':'M00', 'T Year':'T Year':'2023' ] = 
  N:0;
#EndRegion ACT_YEARS

This rule will be parsed by the TM1RuleParser method get_parse_tree and the parsing result will be returned in an instance of TM1Splice.Parser.Grammar.TM1RuleGrammar.TreeNode class. The class contains elements property, which is a list of parsed tokens. You may see a simplified representation of the parsed rule on below picture.

The class defines following attributes:

Attribute	Type	Usage
`directives_resolver`	`TM1DirectiveResolver`	Instance of directive resolver used for splicing (Containers (package)) of the rule.
`regions`	`TM1RegionContainer`	Regions container for splicing of the rule.
`parser`	`Parser`	Instance of parser (Parser/Grammar (package)) to be used to parse the rule.
`current_rule_id`	`TM1RuleID`	Checksum of the current rule calculated from the rule source code (unused).
`generate_rule_id`	`bool`	Flag indicating whether to generate rule IDs or not.

The class exposes following methods:

Method	Usage
`make_empty_line`	Create a `TM1RuleToken` instance representing an empty line.
`make_comment`	Creates a `TM1RuleToken` instance representing a comment or a directive.
`make_command`	Creates a `TM1RuleToken` or `TM1RuleCommand` instance based on type of parsed token. `TM1RuleCommand` instance will be created for calculation rule or a feeder rule (CalcRule non-terminal symbol in grammar), an instance of `TM1RuleToken` in other cases (`skipcheck`, `feeders`, `feedstrings`).
`begin_region`	Creates instance of `TM1RegionStart` when `#Region` was parsed.
`end_region`	Creates instance of `TM1RegionEnd` when `#EndRegion` was parsed.
`make_directive`	Will call `directives_resolver`.`consume_directive` to create an instance of a new `TM1Directive` in the `directives_resolver`.`directives_by_scope` internal store when the parser parsed a directive.
`make_calc_rule`	Creates a `TM1CalcRule` instance when a calculation rule statement was parsed.
`make_feeder_rule`	Creates a `TM1CalcRule` instance when a feeder rule statement was parsed.
`make_area_statement`	Creates a `TM1RuleAreaStatement` instance when an area statement of calculation or a feeder rule was parsed. The instance of the class is `area_statement`property of `TM1CalcRule` created by `make_calc_rule` or `make_feeder_rule`.
`make_ident`	Returns a string representing an identifier parsed by the parser - for example it may be a dimension, hierarchy or element name.
`make_catalog_key`	Returns a string representing an ID to use to retrieve MDX query from `fpm.json` `Catalog` object that is associated with a directive that has been parsed.
`make_region_definition`
`add_dim_to_map`
`add_dim_to_map2`
`make_dim_elem_pair`
`make_hier_elem`
`ignore_dim_elem_pair`
`make_elem_list`
`make_elem_list2`
`make_mdx_query`
`make_hex_footprint`
`make_rule_id`
`splice_rule`
`get_rule`
`get_parse_tree`
`locate_region_subtrees`
`exclude_subtree`
`inject_subtree`

ArgumentParser (class in ArgumentParser.py)

The class implements command line parsing and is used by main application defined in Splicer.py.

The class is using argparse library which doesn’t allow too much flexibility as library click does. Consider changing the library to allow better CLI user experience. The class might also serve as support to expose Splicer as a web service and provide basic parsing of web service headers.