shaping_options.md

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shaping_options

shaping_options contains several settings which are used to shape parsed trees when shaping is used (parser::result::get_shaped_tree()).

It can be provided to a grammar in grammar::options as attribute shaping.

attributes

std::set<size_t> to_trim;

nonterminal ids of symbols to trim (including their children) away from the resulting tree.

List can be provided in TGF with @trim whitespace, comment.

std::set<size_t> to_trim_children;

nonterminal ids of symbols which children will be trimmed away from the resulting tree.

List can be provided in TGF with @trim children sym1, sym2.

std::set<size_t> to_trim_children_terminals;

nonterminal ids of symbols which children terminals will be trimmed away from the resulting tree leaving nonterminals.

List of nonterminals can be provided in TGF with @trim children terminals sym1, sym2.

bool trim_terminals;

If trim_terminals is true it trims all terminals from the resulting parse tree. It is false by default.

This can be set to true in TGF by @trim all terminals.

std::set<std::vector<size_t>> to_inline;

Inline replaces a node with its children. to_inline contains vectors of nonterminal ids.

If a vector contains only a single nonterminal, it means that the nonterminal is replaced by its children.

If a vector contains more than one nonterminal, it searches the parsed tree for occurance of a tree path of nonterminals denoted by nonterminal ids in the vector. First nonterminal is replaced by the last nonterminal node in the vector.

This can be populated by @inline directive.

@inline chars. Node chars is replaced by its children.

@inline expr > block > expr. Node expr containing a child node block which contains a child node expr is replaced by the expr child

bool inline_char_classes;

If inline_char_classes is true shaping will also inline all character class functions. Is a short alternative to adding them into to_inline or @inline one by one.

Default value is false.

In TGF this can be set to true by adding char classes to @inline directive.

@inline char classes.