#  test string expressions and substrings

resource expr()

    char  c5 [1:5] 
    char  c7 [1:7] 
    string[10] s1, s2, s3

    s1 = "alpha"
    s2 = "epsilon"             # string const var assigned to string
    s3 = s1                    # string assignment
    c5 = chars(s1)             # string var assigned to char var
    c7 = chars("upsilon")      # string const var assigned to char var
    write(c5,c7,s1,s2,s3)
    s1 :=: s2                   # string swap
    write(s1,s2)
    s1 = string(c5)            # char var assigned to string
    s2 = string(c7)
    s3 = "*"
    write(s1,s2,s3)
    s1 = "123"
    s2 = "45"
    s1 = "rotorooter"
    c5 = chars(s1[1:5])        # substring reference
    c7 = chars(s1[3:9])
    s1[2:7] = "espira"         # substring assignment
    s1[9] = char(111)          # substring gets char expression
    write(c5,c7,s1)
end