Functions for lexical scanning from input source files. More...

#include <math.h>
#include <string.h>
#include "data.h"
#include "scan.h"
#include "utils/logging.h"

Include dependency graph for scan.c:

Functions
char	next (void)
	Get the next valid character from the current input file. More...

void	put_back_into_stream (char c)
	Put a character back into the input stream. More...

static char	skip_whitespace (void)
	Skips whitespace tokens. More...

static int	index_of (char *s, int c)
	Return the index of char c in string s. More...

static int	char_to_int (char c, int base)
	Convert a character into its integer form. More...

static Number	parse_number_literal (char *literal, int length, int base)

static Number	scan_number_literal (char c)
	Scan and return an integer literal from the input stream. More...

static char	scan_char_literal (char c)
	Scan and return an integer literal from the input stream. More...

static bool	is_valid_identifier_char (char c, int index)
	Determine if a character in an identifier is a permitted character. More...

static int	scan_identifier (char c, char *buf, int max_len)
	Scan an alphanumeric identifier. More...

static TokenType	parse_keyword (char *keyword_string)
	Retrieve the TokenType value corresponding to a keyword string. More...

static bool	scan_check_integer_literal (char c)
	Check if the current character is the start of an integer literal. More...

static bool	scan_check_char_literal (char c)
	Check if the current character is the start of a character literal. More...

static bool	scan_check_keyword_identifier (char c)
	Check if the current character is the start of a keyword or identifier. More...

bool	scan (Token *t)
	Scan tokens into the Token struct. More...

Detailed Description

Functions for lexical scanning from input source files.

Author: Charles Averill

Date: 08-Sep-2022

Function Documentation

◆ char_to_int()

static int char_to_int	(	char	c,
		int	base
	)

static

Convert a character into its integer form.

Parameters

c	Character to convert
base	Base to convert to, or -1 if no limit

Returns: int Value of character

◆ index_of()

static int index_of	(	char *	s,
		int	c
	)

static

Return the index of char c in string s.

Parameters

s	String to search in
c	Character to search for

Returns: int Index of c in s if s contains c, else -1

◆ is_valid_identifier_char()

static bool is_valid_identifier_char	(	char	c,
		int	index
	)

static

Determine if a character in an identifier is a permitted character.

Parameters

c	Character to check
index	Index of character in identifier string

Returns: bool True if character is permitted

◆ next()

char next ( void )

Get the next valid character from the current input file.

Returns: char Next valid character from the current input file

◆ parse_keyword()

static TokenType parse_keyword ( char * keyword_string )

static

Retrieve the TokenType value corresponding to a keyword string.

Parameters

keyword_string String to convert to TokenType

Returns: TokenType TokenType of the keyword, or 0 if the keyword is not recognized

◆ parse_number_literal()

static Number parse_number_literal	(	char *	literal,
		int	length,
		int	base
	)

static

◆ put_back_into_stream()

void put_back_into_stream ( char c )

Put a character back into the input stream.

Parameters

c	Character to be placed into the input stream

◆ scan()

bool scan ( Token * t )

Scan tokens into the Token struct.

Parameters

t	Token to scan data into

Returns: bool Returns true if a Token was scanned successfully

◆ scan_char_literal()

static char scan_char_literal ( char c )

static

Scan and return an integer literal from the input stream.

Parameters

c	Current character

Returns: int Scanned integer literal

◆ scan_check_char_literal()

static bool scan_check_char_literal ( char c )

static

Check if the current character is the start of a character literal.

Parameters

c

Returns: bool True if the current character is the start of a character literal

◆ scan_check_integer_literal()

static bool scan_check_integer_literal ( char c )

static

Check if the current character is the start of an integer literal.

Parameters

c	Character to check

Returns: bool True if the current character is the start of an integer literal

◆ scan_check_keyword_identifier()

static bool scan_check_keyword_identifier ( char c )

static

Check if the current character is the start of a keyword or identifier.

Parameters

c	Character to check

Returns: bool True if the current character is the start of a keyword or identifier

◆ scan_identifier()

static int scan_identifier	(	char	c,
		char *	buf,
		int	max_len
	)

static

Scan an alphanumeric identifier.

Parameters

c	First character in identifier
buf	Buffer to read identifier into
max_len	Maximum length of the identifier

Returns: int Length of the identifier

◆ scan_number_literal()

static Number scan_number_literal ( char c )

static

Scan and return an integer literal from the input stream.

Parameters

c	Current character

Returns: Number Scanned number literal

◆ skip_whitespace()

static char skip_whitespace ( void )

static

Skips whitespace tokens.

Returns: char The next non-whitespace Token