utility Namespace Reference

Utility functions. More...

Classes
class	FlatCharValueMap
	A small cache for each character of a word and an associated value, such as iterator into a trie for each character. More...
struct	ValueIteratorPair
	std::pair neater replacement with appropriate names More...
class	LruCache
	Quick and dirty attempt at implementing an LRU cache. More...

Functions
template<class K , class V >
std::ostream &	operator<< (std::ostream &os, const LruCache< K, V > &cache)
template<class Rng >
auto	words_grouped_by_prefix_suffix (const Rng &words)
	This rather hefty function produces a range of ranges from the input of a range of strings (or a container holding a container of chars). More...
std::vector< std::string >	read_file_as_lines (const char *filepath)
	Read a file at path filepath and return it split by newlines into a std::vector<std::string> More...
std::vector< std::string >	read_file_as_lines (const std::string &filepath)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
std::string	read_file_as_string (const char *filepath)
	Read a file at path filepath into a std::string More...
std::string	read_file_as_string (const std::string &filepath)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
std::vector< std::string >	read_file_as_lines_keep_lowercase_ascii_only (const char *filepath)
	Just like read_file_as_lines() except only keeps lines where all characters are lowercase ascii. More...
std::vector< std::string >	read_file_as_lines_keep_lowercase_ascii_only (const std::string &filepath)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<class String >
void	throw_if_not_lowercase_ascii (const String &word)
template<class Range >
auto	make_adjacent_view (const Range &rng)
	Given a range [1, 2, 3, 4], returns [{1, 2}, {2, 3}, {3, 4}] More...
template<class DataView , class RowIndexes >
auto	make_row_view (DataView &&data_view, const RowIndexes &row_indexes)
	Outputs a row view onto data_view for each difference between indexes in row_indexes. More...

Detailed Description

Utility functions.

Function Documentation

make_adjacent_view()

template<class Range >

auto utility::make_adjacent_view

(

const Range &

rng

)

Given a range [1, 2, 3, 4], returns [{1, 2}, {2, 3}, {3, 4}]

Parameters

[in]

rng

A forward range or better

make_row_view()

template<class DataView , class RowIndexes >

auto utility::make_row_view	(	DataView &&	data_view,
		const RowIndexes &	row_indexes
	)

Outputs a row view onto data_view for each difference between indexes in row_indexes.

Parameters

[in]	data_view	A view onto data
[in]	row_indexes	Indexes splitting the data view into rows

Example: make_row_view("abcdef", {0, 2, 5, 6}) => ("ab", "cde", "f")

read_file_as_lines()

std::vector< std::string > utility::read_file_as_lines

(

const char *

filepath

)

Read a file at path filepath and return it split by newlines into a std::vector<std::string>

Parameters

[in]

filepath

Returns

std::vector<std::string> Each line as a string

Exceptions

std::runtime_error

If there is an error with file opening (file doesn't exist, etc)

read_file_as_lines_keep_lowercase_ascii_only()

std::vector< std::string > utility::read_file_as_lines_keep_lowercase_ascii_only

(

const char *

filepath

)

Just like read_file_as_lines() except only keeps lines where all characters are lowercase ascii.

Read a file at path filepath and return it split by newlines into a std::vector<std::string>

Parameters

[in]

filepath

Returns

std::vector<std::string> Each line as a string

Exceptions

std::runtime_error

If there is an error with file opening (file doesn't exist, etc)

read_file_as_string()

std::string utility::read_file_as_string

(

const char *

filepath

)

Read a file at path filepath into a std::string

Parameters

[in]

filepath

Returns

std::string The file in a string

Exceptions

std::runtime_error

If there is an error with file opening (file doesn't exist, etc)

throw_if_not_lowercase_ascii()

template<class String >

void utility::throw_if_not_lowercase_ascii

(

const String &

word

)

Exceptions

std::runtime_error

words_grouped_by_prefix_suffix()

template<class Rng >

auto utility::words_grouped_by_prefix_suffix

(

const Rng &

words

)

This rather hefty function produces a range of ranges from the input of a range of strings (or a container holding a container of chars).

Parameters

[in]

words

A lexicographically sorted container or view of strings

Returns

See example below.

Note

The input range to this function MUST be sorted, else throws.

Exceptions

std::runtime_error

If the input range is not sorted

It is used for construction of tries. It returns a range of ranges that may be used as such:

std::vector<std::string> lines = {
    "woods", "woody", "wood", "a", "ask",
};
std::sort(lines.begin(), lines.end());
for (auto words_by_length : utility::words_grouped_by_prefix_suffix(lines)) {
  for (auto [prefix, suffix, end_of_word] : words_by_length) {
    fmt::print("Word: \"{}\", suffixes: [{}], end_of_word: {}\n", prefix,
               suffix, end_of_word);
  }
  fmt::print("\n");
}

Output:
Word: "", suffixes: [aw], end_of_word: false
 
Word: "a", suffixes: [s], end_of_word: true
Word: "w", suffixes: [o], end_of_word: false
 
Word: "as", suffixes: [k], end_of_word: false
Word: "wo", suffixes: [o], end_of_word: false
 
Word: "ask", suffixes: [], end_of_word: true
Word: "woo", suffixes: [d], end_of_word: false
 
Word: "wood", suffixes: [sy], end_of_word: true
 
Word: "woods", suffixes: [], end_of_word: true
Word: "woody", suffixes: [], end_of_word: true