/* Copyright (C) 1995 Bjoern Beutel. */

/* Description. =============================================================*/

/* This file contains data structures and functions used for grammatical 
 * analysis. */

/* Types. ===================================================================*/

typedef enum {MORPHOLOGY, SYNTAX} grammar_t; /* Types of grammatic analysis. */

typedef enum {BREAK_NODE, FINAL_NODE, UNFINAL_NODE, INTER_NODE, 
	      PRUNED_NODE} tree_node_type_t;

typedef struct /* A node of the analysis tree. */
{ 
  tree_node_type_t type;
  int_t index; /* Index of this analysis tree node's state or -1. */
  int_t parent_index; /* Index of parent analysis tree node's state or -1. */
  string_t link_surf; /* Link's surface or NULL. */
  value_t link_feat; /* Link's feature structure or NULL. */
  string_t rule_name; /* Name of the rule that created result or NULL. */
  string_t result_surf; /* Surface of resulting state or NULL. */
  value_t result_feat; /* Feature structure of resulting state or NULL. */
  string_t rule_set; /* Successor rules of resulting state or NULL. */
} analysis_node_t;

typedef enum 
{ROBUST_RULE_OPTION, CACHE_OPTION, 
 MOR_OUT_FILTER_OPTION, SYN_IN_FILTER_OPTION, SYN_OUT_FILTER_OPTION, 
 MOR_INCOMPLETE_OPTION, SYN_INCOMPLETE_OPTION,
 ANALYSIS_OPTION_COUNT} analysis_option_t;

typedef enum {STATE_SURFACE, LINK_SURFACE, RESULT_SURFACE} surface_t;
/* Kinds of surfaces that can be obtained by "get_rule_info" in "rules.h" */

/* Variables. ===============================================================*/

extern rule_sys_t *rule_system[2];
/* rule_system[ MORPHOLOGY ] and rule_system[ SYNTAX ]. Read only! */

extern grammar_t top_grammar; /* Grammar of last analysis. Read only! */

extern int_t state_count; /* Counts number of generated states. Read only! */

extern int_t current_state; /* Index of current state. Read only! */

extern bool_t recognised_by_combi_rules;
/* TRUE if last analysis was recognised by combi rules. Read only! */

extern bool_t recognised_by_robust_rule; 
/* TRUE if last analysis was recognised by robust rule. Read only! */

extern string_t last_analysis_input; 
/* Start of top level input string. Read only! */

extern void (*debug_state)( int_t index, bool_t enter );
/* Callback function for "analyse".
 * This is called with ENTER == TRUE when successor rules for
 * state with analysis node INDEX will be executed.
 * It is called with ENTER == FALSE when successor rules for state with 
 * analysis node INDEX have been executed. */

extern char_t * (*get_surface)( surface_t surface_type );
/* Return surface SURFACE_TYPE for currently executed rule.
 * The result must be freed after use. */

extern int_t mor_pruning_min; 
/* Minimum number of states that must have consumed same amount of input
 * needed to call the morphology pruning rule. Value 0 disables pruning. */

extern int_t syn_pruning_min; 
/* Minimum number of states that must have consumed same amount of input
 * needed to call the syntax pruning rule. Value 0 disables pruning. */

/* Functions. ===============================================================*/

extern void init_analysis( string_t morphology_file, string_t syntax_file );
/* Initialise the analysis module.
 * MORPHOLOGY_FILE and SYNTAX_FILE are the rule files to load. 
 * SYNTAX_FILE may be NULL. */

extern void terminate_analysis( void );
/* Free analysis module. */

extern void preprocess_input( char_t *input, bool_t expect_quotes);
/* Delete heading and trailing spaces in INPUT
 * and compress all whitespace sequences to a single space.
 * If EXPECT_QUOTES == TRUE, expect quoted input and remove the quotes. */

extern void set_analysis_option( analysis_option_t selected, bool_t setting );
/* Set analysis option SELECTED to SETTING. */

extern bool_t get_analysis_option( analysis_option_t selected );
/* Return the current setting of analysis option SELECTED. */

extern void analyse( grammar_t grammar, 
		     string_t input, 
		     bool_t create_tree,
		     bool_t analyse_all );
/* Perform a LAG analysis of INPUT using GRAMMAR (MORPHOLOGY or SYNTAX).
 * An analysis tree will be built if CREATE_TREE == TRUE.
 * The whole input will be analysed if ANALYSE_ALL == TRUE. */

extern bool_t analysis_has_results( void );
/* Return TRUE iff the last analysis has created results. */

extern value_t first_analysis_result( void );
/* Return the feature structure of the first analysis result.
 * Return NULL if there are no results. */

extern value_t next_analysis_result( void );
/* Return the feature structure of the next analysis result.
 * Return NULL if there are no more results. */

extern bool_t analysis_has_nodes( void );
/* Return TRUE iff the last analysis has created tree nodes. */

extern analysis_node_t *get_first_analysis_node( void );
/* Return the first analysis tree node of the last analysis.
 * Return NULL if there is no node. 
 * The node must be freed with "free_analysis_node" after use. */

extern analysis_node_t *get_next_analysis_node( void );
/* Return the next analysis tree node of the last analysis.
 * Return NULL if there is no more node. 
 * The node must be freed with "free_analysis_node" after use. */

extern void free_analysis_node( analysis_node_t **node );
/* Free the memory occupied by NODE. */

/* End of file. =============================================================*/