about summary refs log blame commit diff stats
path: root/068random.mu
blob: 8de6630f90bb7d2152f98473768f4b0bd72ae2ca (plain) (tree)
<
; To demonstrate tangle directives, we'll construct a factorial function with
; separate base and recursive cases. Compare factorial.mu.
; This isn't a very realistic example, just a simple demonstration of
; possibilities.

(function factorial [
  (default-space:space-address <- new space:literal 30:literal)
  (n:integer <- next-input)
  { begin
    base-case
  }
  recursive-case
])

(after base-case [
  ; if n=0 return 1
  (zero?:boolean <- equal n:integer 0:literal)
  (break-unless zero?:boolean)
  (reply 1:literal)
])

(after recursive-case [
  ; return n*factorial(n-1)
  (x:integer <- subtract n:integer 1:literal)
  (subresult:integer <- factorial x:integer)
  (result:integer <- multiply subresult:integer n:integer)
  (reply result:integer)
])

(function main [
  pre { line-height: 125%; }
td.linenos .normal { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
span.linenos { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
td.linenos .special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
def random generator:&:stream:num -> result:num, fail?:bool, generator:&:stream:num [
  local-scope
  load-ingredients
  {
    break-if generator
    # generator is 0? use real random-number generator
    result <- real-random
    return result, 0/false
  }
  result, fail?, generator <- read generator
]

# helper for tests
def assume-random-numbers -> result:&:stream:num [
  local-scope
  load-ingredients
  # compute result-len, space to allocate in result
  result-len:num <- copy 0
  {
    _, arg-received?:bool <- next-ingredient
    break-unless arg-received?
    result-len <- add result-len, 1
    loop
  }
  rewind-ingredients
  result-data:&:@:num <- new number:type, result-len
  idx:num <- copy 0
  {
    curr:num, arg-received?:bool <- next-ingredient
    break-unless arg-received?
    *result-data <- put-index *result-data, idx, curr
    idx <- add idx, 1
    loop
  }
  result <- new-stream result-data
]

scenario random-numbers-in-scenario [
  local-scope
  source:&:stream:num <- assume-random-numbers 34, 35, 37
  1:num/raw, 2:bool/raw <- random source
  3:num/raw, 4:bool/raw <- random source
  5:num/raw, 6:bool/raw <- random source
  7:num/raw, 8:bool/raw <- random source
  memory-should-contain [
    1 <- 34
    2 <- 0  # everything went well
    3 <- 35
    4 <- 0  # everything went well
    5 <- 37
    6 <- 0  # everything went well
    7 <- 0  # empty result
    8 <- 1  # end of stream
  ]
]

def random-in-range generator:&:stream:num, start:num, end:num -> result:num, fail?:bool, generator:&:stream:num [
  local-scope
  load-ingredients
  result, fail?, generator <- random generator
  return-if fail?
  delta:num <- subtract end, start
  _, result <- divide-with-remainder result, delta
  result <- add result, start
]

scenario random-in-range [
  local-scope
  source:&:stream:num <- assume-random-numbers 91
  1:num/raw <- random-in-range source, 40, 50
  memory-should-contain [
    1 <- 41
  ]
]