parser_result.md

back to index

parser::result

result is a structure returned by a parse call. It contains a parsed forest, input and provides means to extract parsed information, trees and input characters.

attributes

const bool found;

found contains true if the starting symbol was successfuly parsed over the whole input. Otherwise it contains false.

const parser::error parse_error;

If found is false, parse_error contains information why parsing failed.

const shaping_options shaping;

Contains information how to shape a parsed tree when using get_shaped_forest_tree() or get_shaped_bintree() methods.

methods

pforest* get_forest() const;

Returns pointer to the parsed forest. In bintree parse mode the forest is built lazily on first call (recorded as reconstruct_forest in diagnostics).

tref get_bintree();

tref get_bintree(const pnode& n);

Returns the parse tree as a bintree (tref). In forest parse mode the tree is extracted lazily on first call (reconstruct_bintree with extract graph, inline grammar, and extract tree2 substeps in diagnostics).

get_tree2() / get_tree2(const pnode& n) are aliases.

Tree representations

result provides two families of tree-access and shaping APIs, distinguished by the tree representation they operate on:

Family	Return type	Preferred naming	Legacy names (aliases)
Forest-tree	psptree	*_forest_tree*	get_trimmed_tree, get_shaped_tree, get_tree, inline_tree, etc.
Bintree	tref	*_bintree*	get_tree2, get_shaped_tree2, etc.

Forest-tree methods work with the parse forest and return psptree (shared pointer to ptree). Bintree methods work with a binary-tree representation (tref) and are native when parse_options::tree_path == bintree_path (the default).

All legacy names remain available as inline wrappers that delegate to the preferred implementations.

Forest-tree API (psptree)

psptree get_trimmed_forest_tree(const pnode& n) const;

psptree get_trimmed_forest_tree(const pnode& n, const shaping_options opts) const;

Legacy name: get_trimmed_tree (still available as an alias).

Transforms forest into a tree and applies trimming according to grammar options or shaping options provided as an argument.

It also transforms ambiguous nodes as children of __AMB__ nodes.

This is called by get_shaped_forest_tree().

psptree inline_forest_tree_nodes(const psptree& t, psptree& parent) const;

psptree inline_forest_tree_nodes(const psptree& t, psptree& parent, const shaping_options opts) const;

Legacy name: inline_tree_nodes (still available as an alias).

Applies inlining to a tree (w/o tree paths) according to grammar options or shaping options provided as an argument.

This is called by inline_forest_tree().

psptree inline_forest_tree_paths(const psptree& t) const;

psptree inline_forest_tree_paths(const psptree& t, const shaping_options opts) const;

Legacy name: inline_tree_paths (still available as an alias).

Applies tree paths inlining to a tree according to grammar options or shaping options provided as an argument.

This is called by inline_forest_tree().

psptree inline_forest_tree(psptree& t) const;

psptree inline_forest_tree(psptree& t, const shaping_options opts) const;

Legacy name: inline_tree (still available as an alias).

Applies inlining to a tree according to grammar options or shaping options provided as an argument. Calls inline_forest_tree_nodes() and inline_forest_tree_paths().

This is called by get_shaped_forest_tree().

psptree trim_forest_tree_child_terminals(const psptree& t) const;

psptree trim_forest_tree_child_terminals(const psptree& t, const shaping_options opts) const;

Legacy name: trim_children_terminals (still available as an alias).

Trims children terminals from a tree according to grammar options or shaping options provided as an argument.

This is called by get_shaped_forest_tree().

psptree get_shaped_forest_tree() const;

psptree get_shaped_forest_tree(const shaping_options opts) const;

psptree get_shaped_forest_tree(const pnode& n) const;

psptree get_shaped_forest_tree(const pnode& n, const shaping_options opts) const;

Legacy name: get_shaped_tree (still available as an alias).

Transforms forest into a tree and applies shaping according to grammar options or shaping options provided as an argument.

psptree get_forest_tree();

psptree get_forest_tree(const pnode& n);

Legacy name: get_tree (still available as an alias).

Extracts the first parse tree from the parsed forest.

Bintree API (tref)

tref get_trimmed_bintree(tref ref) const;

tref get_trimmed_bintree(tref ref, const shaping_options opts) const;

Legacy name: get_trimmed_tree2 (still available as an alias).

Trims a bintree according to grammar options or shaping options provided as an argument.

This is called by get_shaped_bintree().

tref inline_bintree_nodes(tref t) const;

tref inline_bintree_nodes(tref t, const shaping_options opts) const;

Legacy name: inline_tree_nodes2 (still available as an alias).

Applies inlining to a bintree (w/o tree paths) according to grammar options or shaping options provided as an argument.

This is called by inline_bintree().

tref inline_bintree_paths(tref t) const;

tref inline_bintree_paths(tref t, const shaping_options opts) const;

Legacy name: inline_tree_paths2 (still available as an alias).

Applies tree paths inlining to a bintree according to grammar options or shaping options provided as an argument.

This is called by inline_bintree().

tref inline_bintree(tref t) const;

tref inline_bintree(tref t, const shaping_options opts) const;

Legacy name: inline_tree2 (still available as an alias).

Applies inlining to a bintree according to grammar options or shaping options provided as an argument. Calls inline_bintree_nodes() and inline_bintree_paths().

This is called by get_shaped_bintree().

tref trim_bintree_child_terminals(tref ref) const;

tref trim_bintree_child_terminals(tref ref, const shaping_options opts) const;

Legacy name: trim_children_terminals2 (still available as an alias).

Trims children terminals from a bintree according to grammar options or shaping options provided as an argument.

This is called by get_shaped_bintree().

tref get_shaped_bintree();

tref get_shaped_bintree(const shaping_options opts);

tref get_shaped_bintree(tref t);

tref get_shaped_bintree(tref t, const shaping_options opts);

Legacy name: get_shaped_tree2 (still available as an alias).

Transforms forest into a bintree and applies shaping according to grammar options or shaping options provided as an argument. If no tref argument is given, uses get_bintree() to obtain the root.

bool good() const;

true if input is good = stream is good or mmap is opened.

std::basic_string get_input();

Returns the input as a string (input's char type, ie. C).

std::basic_string get_terminals() const;

Read terminals from input (input's terminal type, ie. T).

std::basic_string get_terminals(const pnode& n) const;

std::basic_ostream& get_terminals_to_stream(std::basic_ostream& os, const pnode& n) const;

Read terminals from input at position span of a provided node.

std::optional<int_t> get_terminals_to_int(const pnode& n) const;

Reads terminals of a node and converts them to int. If the conversion fails or the int is out of range returns no value.

bool is_ambiguous() const;

Returns true if the parse forest is ambiguous (contains more than one tree).

bool has_single_parse_tree() const;

Returns true if the parse forest is not ambiguous (contains only a single tree).

std::set<std::pair<pnode, pnodes_set>> ambiguous_nodes() const;

Returns ambiguous nodes.

std::ostream& print_ambiguous_nodes(std::ostream& os) const;

Prints ambiguous nodes.

nodes_and_edges get_nodes_and_edges() const;

Returns all nodes and edges of the forest. It is a pair of vectors of nodes and edges. edge is defined as a pair of node ids.

using node_edge       = std::pair<pnode, pnode>;
using edges           = std::vector<typename pforest::edge>;
using nodes_and_edges = std::pair<pnodes, edges>;

bool inline_prefixed_nodes(pgraph& g, const std::string& prefix);

Removes all prefixed symbols from the whole graph by replacing them with their immediate children nodes.

bool inline_grammar_transformations(pgraph& g);

Inlines nodes created by EBNF and binarize transformation prefixes.