--- a/js/flotr2/examples/lib/codemirror/mode/ruby/index.html +++ b/js/flotr2/examples/lib/codemirror/mode/ruby/index.html @@ -1,1 +1,172 @@ + + + + CodeMirror: Ruby mode + + + + + + + +

CodeMirror: Ruby mode

+# Code from http://sandbox.mc.edu/~bennet/ruby/code/poly_rb.html
+#
+# This program evaluates polynomials.  It first asks for the coefficients
+# of a polynomial, which must be entered on one line, highest-order first.
+# It then requests values of x and will compute the value of the poly for
+# each x.  It will repeatly ask for x values, unless you the user enters
+# a blank line.  It that case, it will ask for another polynomial.  If the
+# user types quit for either input, the program immediately exits.
+#
 
+#
+# Function to evaluate a polynomial at x.  The polynomial is given
+# as a list of coefficients, from the greatest to the least.
+def polyval(x, coef)
+    sum = 0
+    coef = coef.clone           # Don't want to destroy the original
+    while true
+        sum += coef.shift       # Add and remove the next coef
+        break if coef.empty?    # If no more, done entirely.
+        sum *= x                # This happens the right number of times.
+    end
+    return sum
+end
+
+#
+# Function to read a line containing a list of integers and return
+# them as an array of integers.  If the string conversion fails, it
+# throws TypeError.  If the input line is the word 'quit', then it
+# converts it to an end-of-file exception
+def readints(prompt)
+    # Read a line
+    print prompt
+    line = readline.chomp
+    raise EOFError.new if line == 'quit' # You can also use a real EOF.
+            
+    # Go through each item on the line, converting each one and adding it
+    # to retval.
+    retval = [ ]
+    for str in line.split(/\s+/)
+        if str =~ /^\-?\d+$/
+            retval.push(str.to_i)
+        else
+            raise TypeError.new
+        end
+    end
+
+    return retval
+end
+
+#
+# Take a coeff and an exponent and return the string representation, ignoring
+# the sign of the coefficient.
+def term_to_str(coef, exp)
+    ret = ""
+
+    # Show coeff, unless it's 1 or at the right
+    coef = coef.abs
+    ret = coef.to_s     unless coef == 1 && exp > 0
+    ret += "x" if exp > 0                               # x if exponent not 0
+    ret += "^" + exp.to_s if exp > 1                    # ^exponent, if > 1.
+
+    return ret
+end
+
+#
+# Create a string of the polynomial in sort-of-readable form.
+def polystr(p)
+    # Get the exponent of first coefficient, plus 1.
+    exp = p.length
+
+    # Assign exponents to each term, making pairs of coeff and exponent,
+    # Then get rid of the zero terms.
+    p = (p.map { |c| exp -= 1; [ c, exp ] }).select { |p| p[0] != 0 }
+
+    # If there's nothing left, it's a zero
+    return "0" if p.empty?
+
+    # *** Now p is a non-empty list of [ coef, exponent ] pairs. ***
+
+    # Convert the first term, preceded by a "-" if it's negative.
+    result = (if p[0][0] < 0 then "-" else "" end) + term_to_str(*p[0])
+
+    # Convert the rest of the terms, in each case adding the appropriate
+    # + or - separating them.  
+    for term in p[1...p.length]
+        # Add the separator then the rep. of the term.
+        result += (if term[0] < 0 then " - " else " + " end) + 
+                term_to_str(*term)
+    end
+
+    return result
+end
+        
+#
+# Run until some kind of endfile.
+begin
+    # Repeat until an exception or quit gets us out.
+    while true
+        # Read a poly until it works.  An EOF will except out of the
+        # program.
+        print "\n"
+        begin
+            poly = readints("Enter a polynomial coefficients: ")
+        rescue TypeError
+            print "Try again.\n"
+            retry
+        end
+        break if poly.empty?
+
+        # Read and evaluate x values until the user types a blank line.
+        # Again, an EOF will except out of the pgm.
+        while true
+            # Request an integer.
+            print "Enter x value or blank line: "
+            x = readline.chomp
+            break if x == ''
+            raise EOFError.new if x == 'quit'
+
+            # If it looks bad, let's try again.
+            if x !~ /^\-?\d+$/
+                print "That doesn't look like an integer.  Please try again.\n"
+                next
+            end
+
+            # Convert to an integer and print the result.
+            x = x.to_i
+            print "p(x) = ", polystr(poly), "\n"
+            print "p(", x, ") = ", polyval(x, poly), "\n"
+        end
+    end
+rescue EOFError
+    print "\n=== EOF ===\n"
+rescue Interrupt, SignalException
+    print "\n=== Interrupted ===\n"
+else
+    print "--- Bye ---\n"
+end
+

+ + +

MIME types defined: text/x-ruby.

+ +

Development of the CodeMirror Ruby mode was kindly sponsored + by Ubalo, who hold + the license.

+ + + +