Selected Subroutines

A routine shown without a prefix is built-in. A routine shown with a prefix requires an include file. The prefix is optional (unless there is a name clash) but is shown as a reminder that an include file is needed. For example: if you write include std/console.e then you can use console:display or just display in a statement.

For examples of their usage see sanity.ex or the other Euphoria files. Complete details are available in the Euphoria Reference Manual.

To indicate what may be passed in and returned the following prefixes are used:

x  -- a general object (sequence or atom) 
a  -- an atom 
s  -- a sequence 
i  -- an integer 
fn -- an integer file number 
st --  a string sequence or single-character atom 

Types:

i = integer(x)         -- is x an integer? 
i = atom(x)            -- is x an atom? 
i = sequence(x)        -- is x a sequence? 
i = object(x)          -- is x initialized? 

Operations on Objects:

i = length(x)          -- length of sequence 
s = repeat(x, a)       -- repeat x a times 
s2 = append(x1, x)     -- append x to end of s1 
s2 = prepend(x1, x)    -- prepend x at beginning of s1 

Searching and Sorting:

i = compare(x1, x2)    -- compare x1 to x2, return +1, -1 or 0 
i = find(x, s)         -- find position of x as an item within s 
i = match(s1, s2)      -- find position of s1 as a slice within s2 
x2 = sort:sort(s)      -- sort a sequence of arbitrary objects 
				       -- [include std/sort.e ] 

File I/O:

fn = open(st1, st2)    -- open file name st1 with mode st2 e.g. "r" 

Some files are opened automatically for you:

0 -- standard input 
1 -- standard output 
2 -- standard error 
close(fn)              -- close file number fn 
print(fn, x)           -- print value of x to file fn 
printf(fn, st, x)      -- formatted print. st contains %d, %f, %s etc. 

x is a sequence of values to be formatted

puts(fn, st)           -- output string st to file fn 
i = getc(fn)           -- get next character from file fn (-1 is EOF) 
x = gets(fn)           -- get next line from file fn (-1 is EOF) 
i = get_key()          -- get key pressed, or return -1 
s = get(fn)            -- read next Euphoria object representation from 
                       -- file fn  [include get.e and see comments in get.e] 

Operating System

a = time()             -- time in seconds since a fixed point 
s = date()             -- {year, month, day, hour, minute, second, 
				   day of week, day of year} 
s = command_line()     -- sequence of words from ex command line 
system(s, i)           -- execute a operating system command s,  
			  i = 0 => restore graphics mode 
			  i = 1 => beep, wait for key press, then restore graphics mode 
			  i = 2 => don't restore graphics mode 
s2 = getenv(s1)        -- return value of an environment variable 

Debugging:

trace(a)               -- turn tracing on (1) or off (0) 

Console or Terminal:

While you can write graphical programs with Euphoria, this mini manual only shows a few text mode routines:

clear_screen()         -- clear the screen 
console:position(a1, a2)       -- move cursor to line a1, column a2 
                               -- [include std/console.e] 

for the following, include std/graphics.e and read the comments and code in graphics.e for more details

graphcst: = video_config()     -- {color monitor?, mode, rows, columns, 
				               -- xpixels, ypixels, #colors} 
graphics:scroll(i)              -- scroll screen up or down 
graphics:wrap(i)                -- wrap or not at right margin 
graphics:text_color(i)          -- foreground text color 
graphics:bk_color(i)            -- background text or graphics color 

Math:

x2 = sqrt(x1)          -- square root 
x2 = rand(x1)          -- random number 
x2 = sin(x1)           -- trig function 
x2 = cos(x1)           -- trig function 
x2 = tan(x1)           -- trig function 
x2 = log(x1)           -- natural log 
x2 = floor(x1)         -- round down to an integer 
x2 = remainder(x1, x2) -- remainder when x1 is divided by x2 
x2 = power(x1, x2)     -- x1 to the power x2