Each record describing a state in the LALR State Table is preceded by a byte field containing the value 76 - the ASCII code for "L". The file will contain one of these records for each state in the table. The Table Count record, which precedes any LALR records, will contain the total number of states.
A LALR State contains a series of actions that are performed based on the next token. The record mostly consists of a series of fields (in groups of 4) which describe each of these actions.
| Item | Type | Description |
|---|---|---|
| Index | Integer | This parameter holds the index of the state in the LALR State Table. |
| (Reserved) | Empty | This field is reserved for future use. |
| Action 0...n | Described below. |
| Value | Type | Description |
|---|---|---|
| Symbol Index | Integer | This field contains the index in the Symbol Table. |
| Action | Integer | This field contains a value that represents the action that LALR parsing engine is to take based on the symbol. These values are enumerated below. |
| Target | Integer | Depending on the value of the Action field, the target will hold different types of information. |
| (Reserved) | Empty | This field is reserved for future use. |
| Value | Name | Description |
|---|---|---|
| 1 | ActionShift | This action indicates the symbol is to be shifted. The Target field will contain the index of the state in the LALR State table that the parsing engine will advance to. |
| 2 | ActionReduce | This action denotes that the parser can reduce a rule. The Target field will contain the index of the rule in the Rule Table. |
| 3 | ActionGoto | This action is used when a rule is reduced and the parser jumps to the state that represents the shifted nonterminal. The Target field will contain the index of the state in the LALR State table that the parsing engine will jump to after a reduction if completed. |
| 4 | ActionAccept | When the parser encounters the Accept action for a given symbol, the source text is accepted as correct and complete. In this case, the Target field is not needed and should be ignored. |