Lexer (Calculemus)

Lexer Module

Namespace: Calculemus.Lib
Assembly: Calculemus.dll

Lexical analysis.

Note

The functions for lexical analysis in the original code where in the Intro module and have been moved here for isolation purposes.

Functions and values

Function or value	Description
`alphanumeric s` Full Usage: `alphanumeric s` Parameters: s : `string` - The single character string to be classified. Returns: `bool` true if the single character string it is considered alphanumeric, otherwise false.	Classifies single character strings as alphanumeric. s : `string` The single character string to be classified. Returns: `bool` true if the single character string it is considered alphanumeric, otherwise false. Example `alphanumeric "1"` Evaluates to `true`. Example `alphanumeric "z"` Evaluates to `true`. Example `alphanumeric "."` Evaluates to `false`.
`lex inp` Full Usage: `lex inp` Parameters: inp : `string list` - The input list of single character strings to be tokenized. Returns: `string list` The input list of single character strings tokenized.	Lexical analyser. It maps a list of input characters `inp` into a list of token strings. inp : `string list` The input list of single character strings to be tokenized. Returns: `string list` The input list of single character strings tokenized. Example `"((11 + 2) * x_1)" \|> explode \|> lex` Evaluates to `["("; "("; "11"; "+"; "2"; ")"; "*"; "x_1"; ")"]`. Note how `11` and `x_1` are analyzed as a single tokens.
`lexwhile prop inp` Full Usage: `lexwhile prop inp` Parameters: prop : `string -> bool` - The predicate to identify tokens. inp : `string list` - The input list of single character strings. Returns: `string * string list` A pair with the longest initial sequence of elements of `inp` classifiable as satisfying `prop` as the first component, and the remaining characters as the second.	Takes a property `prop` of characters (such as one of the classifying predicates: Lexer.space, Lexer.punctuation, Lexer.symbolic, Lexer.numeric, Lexer.alphanumeric) and a list of single character strings `inp`, separating off as a string the longest initial sequence of that list of characters satisfying `prop`. prop : `string -> bool` The predicate to identify tokens. inp : `string list` The input list of single character strings. Returns: `string * string list` A pair with the longest initial sequence of elements of `inp` classifiable as satisfying `prop` as the first component, and the remaining characters as the second. Example `"((1 + 2) * x_1)" \|> explode \|> lexwhile punctuation` Evaluates to `("((", ["1"; " "; "+"; " "; "2"; ")"; " "; "*"; " "; "x"; "_"; "1"; ")"])`.
`matches s` Full Usage: `matches s` Parameters: s : `string` - The string of all characters to be matched. Returns: `string -> bool` A function that applied to a single character string checks if it matches the given pattern.	Creates a pattern matching function based on the input string `s` as the pattern. s : `string` The string of all characters to be matched. Returns: `string -> bool` A function that applied to a single character string checks if it matches the given pattern. Example `matches "abc" "a"` Evaluates to `true`. Example `matches "abc" "d"` Evaluates to `false`.
`numeric s` Full Usage: `numeric s` Parameters: s : `string` - The single character string to be classified. Returns: `bool` true if the single character string it is considered numeric, otherwise false.	Classifies single character strings as numeric. s : `string` The single character string to be classified. Returns: `bool` true if the single character string it is considered numeric, otherwise false. Example `numeric "1"` Evaluates to `true`. Example `numeric "z"` Evaluates to `false`.
`punctuation s` Full Usage: `punctuation s` Parameters: s : `string` - The single character string to be classified. Returns: `bool` true if the single character string it is considered a punctuation symbol, otherwise false.	Classifies single character strings as punctuation symbols: `()[]{},`. s : `string` The single character string to be classified. Returns: `bool` true if the single character string it is considered a punctuation symbol, otherwise false. Example `punctuation ","` Evaluates to `true`. Example `punctuation "."` Evaluates to `false`.
`space s` Full Usage: `space s` Parameters: s : `string` - The single character string to be classified. Returns: `bool` true if the single character string it is considered a space, otherwise false.	Classifies single character strings as spaces. Tabs and new lines are also considered spaces. s : `string` The single character string to be classified. Returns: `bool` true if the single character string it is considered a space, otherwise false. Example `space " "` Evaluates to `true`. Example `space "."` Evaluates to `false`.
`symbolic s` Full Usage: `symbolic s` Parameters: s : `string` - The single character string to be classified. Returns: `bool` true if the single character string it is considered symbolic, otherwise false.	Classifies single character strings as symbolic: ~`!@#$%^&*-+=\|\\:;<>.?/. s : `string` The single character string to be classified. Returns: `bool` true if the single character string it is considered symbolic, otherwise false. Example `symbolic "."` Evaluates to `true`. Example `symbolic "1"` Evaluates to `false`.