3400

Undo commit 3340. Let's standardize names of non-core files to only have
dashes. That's also consistent with the edit/ and sandbox/ apps. Mu
programmers will tend to pervasively use dashes, just like Lisp
programmers.

Scripts will continue to use underscores..

1 files changed, 584 insertions, 0 deletions

diff --git a/lambda-to-mu.mu b/lambda-to-mu.mu
new file mode 100644
index 00000000..0bdeb43f
--- /dev/null
+++ b/lambda-to-mu.mu
@@ -0,0 +1,584 @@
+## experimental compiler to translate programs written in a generic
+## expression-oriented language called 'lambda' into mu
+
+scenario convert-lambda [
+  run [
+    local-scope
+    1:text/raw <- lambda-to-mu [(add a (multiply b c))]
+    2:@:char/raw <- copy *1:text/raw
+  ]
+  memory-should-contain [
+    2:@:char <- [t1 <- multiply b c
+result <- add a t1]
+  ]
+]
+
+def lambda-to-mu in:text -> out:text [
+  local-scope
+  load-ingredients
+  out <- copy 0
+  cells:&:cell <- parse in
+  out <- to-mu cells
+]
+
+# 'parse' will turn lambda expressions into trees made of cells
+exclusive-container cell [
+  atom:text
+  pair:pair
+]
+
+# printed below as < first | rest >
+container pair [
+  first:&:cell
+  rest:&:cell
+]
+
+def new-atom name:text -> result:&:cell [
+  local-scope
+  load-ingredients
+  result <- new cell:type
+  *result <- merge 0/tag:atom, name
+]
+
+def new-pair a:&:cell, b:&:cell -> result:&:cell [
+  local-scope
+  load-ingredients
+  result <- new cell:type
+  *result <- merge 1/tag:pair, a/first, b/rest
+]
+
+def is-atom? x:&:cell -> result:boolean [
+  local-scope
+  load-ingredients
+  reply-unless x, 0/false
+  _, result <- maybe-convert *x, atom:variant
+]
+
+def is-pair? x:&:cell -> result:boolean [
+  local-scope
+  load-ingredients
+  reply-unless x, 0/false
+  _, result <- maybe-convert *x, pair:variant
+]
+
+scenario atom-is-not-pair [
+  local-scope
+  s:text <- new [a]
+  x:&:cell <- new-atom s
+  10:boolean/raw <- is-atom? x
+  11:boolean/raw <- is-pair? x
+  memory-should-contain [
+    10 <- 1
+    11 <- 0
+  ]
+]
+
+scenario pair-is-not-atom [
+  local-scope
+  # construct (a . nil)
+  s:text <- new [a]
+  x:&:cell <- new-atom s
+  y:&:cell <- new-pair x, 0/nil
+  10:boolean/raw <- is-atom? y
+  11:boolean/raw <- is-pair? y
+  memory-should-contain [
+    10 <- 0
+    11 <- 1
+  ]
+]
+
+def atom-match? x:&:cell, pat:text -> result:boolean [
+  local-scope
+  load-ingredients
+  s:text, is-atom?:boolean <- maybe-convert *x, atom:variant
+  reply-unless is-atom?, 0/false
+  result <- equal pat, s
+]
+
+scenario atom-match [
+  local-scope
+  x:&:cell <- new-atom [abc]
+  10:boolean/raw <- atom-match? x, [abc]
+  memory-should-contain [
+    10 <- 1
+  ]
+]
+
+def first x:&:cell -> result:&:cell [
+  local-scope
+  load-ingredients
+  pair:pair, pair?:boolean <- maybe-convert *x, pair:variant
+  reply-unless pair?, 0/nil
+  result <- get pair, first:offset
+]
+
+def rest x:&:cell -> result:&:cell [
+  local-scope
+  load-ingredients
+  pair:pair, pair?:boolean <- maybe-convert *x, pair:variant
+  reply-unless pair?, 0/nil
+  result <- get pair, rest:offset
+]
+
+def set-first base:&:cell, new-first:&:cell -> base:&:cell [
+  local-scope
+  load-ingredients
+  pair:pair, is-pair?:boolean <- maybe-convert *base, pair:variant
+  reply-unless is-pair?
+  pair <- put pair, first:offset, new-first
+  *base <- merge 1/pair, pair
+]
+
+def set-rest base:&:cell, new-rest:&:cell -> base:&:cell [
+  local-scope
+  load-ingredients
+  pair:pair, is-pair?:boolean <- maybe-convert *base, pair:variant
+  reply-unless is-pair?
+  pair <- put pair, rest:offset, new-rest
+  *base <- merge 1/pair, pair
+]
+
+scenario cell-operations-on-atom [
+  local-scope
+  s:text <- new [a]
+  x:&:cell <- new-atom s
+  10:&:cell/raw <- first x
+  11:&:cell/raw <- rest x
+  memory-should-contain [
+    10 <- 0  # first is nil
+    11 <- 0  # rest is nil
+  ]
+]
+
+scenario cell-operations-on-pair [
+  local-scope
+  # construct (a . nil)
+  s:text <- new [a]
+  x:&:cell <- new-atom s
+  y:&:cell <- new-pair x, 0/nil
+  x2:&:cell <- first y
+  10:boolean/raw <- equal x, x2
+  11:&:cell/raw <- rest y
+  memory-should-contain [
+    10 <- 1  # first is correct
+    11 <- 0  # rest is nil
+  ]
+]
+
+## convert lambda text to a tree of cells
+
+def parse in:text -> out:&:cell [
+  local-scope
+  load-ingredients
+  s:&:stream:char <- new-stream in
+  out, s <- parse s
+  trace 2, [app/parse], out
+]
+
+def parse in:&:stream:char -> out:&:cell, in:&:stream:char [
+  local-scope
+  load-ingredients
+  # skip whitespace
+  in <- skip-whitespace in
+  c:char, eof?:boolean <- peek in
+  reply-if eof?, 0/nil
+  pair?:boolean <- equal c, 40/open-paren
+  {
+    break-if pair?
+    # atom
+    b:&:buffer <- new-buffer 30
+    {
+      done?:boolean <- end-of-stream? in
+      break-if done?
+      # stop before close paren or space
+      c:char <- peek in
+      done? <- equal c, 41/close-paren
+      break-if done?
+      done? <- space? c
+      break-if done?
+      c <- read in
+      b <- append b, c
+      loop
+    }
+    s:text <- buffer-to-array b
+    out <- new-atom s
+  }
+  {
+    break-unless pair?
+    # pair
+    read in  # skip the open-paren
+    out <- new cell:type  # start out with nil
+    # read in first element of pair
+    {
+      end?:boolean <- end-of-stream? in
+      not-end?:boolean <- not end?
+      assert not-end?, [unbalanced '(' in expression]
+      c <- peek in
+      close-paren?:boolean <- equal c, 41/close-paren
+      break-if close-paren?
+      first:&:cell, in <- parse in
+      *out <- merge 1/pair, first, 0/nil
+    }
+    # read in any remaining elements
+    curr:&:cell <- copy out
+    {
+      in <- skip-whitespace in
+      end?:boolean <- end-of-stream? in
+      not-end?:boolean <- not end?
+      assert not-end?, [unbalanced '(' in expression]
+      # termination check: ')'
+      c <- peek in
+      {
+        close-paren?:boolean <- equal c, 41/close-paren
+        break-unless close-paren?
+        read in  # skip ')'
+        break +end-pair:label
+      }
+      # still here? read next element of pair
+      next:&:cell, in <- parse in
+      is-dot?:boolean <- atom-match? next, [.]
+      {
+        break-if is-dot?
+        next-curr:&:cell <- new-pair next, 0/nil
+        curr <- set-rest curr, next-curr
+        curr <- rest curr
+      }
+      {
+        break-unless is-dot?
+        # deal with dotted pair
+        in <- skip-whitespace in
+        c <- peek in
+        not-close-paren?:boolean <- not-equal c, 41/close-paren
+        assert not-close-paren?, [')' cannot immediately follow '.']
+        final:&:cell <- parse in
+        curr <- set-rest curr, final
+        # we're not gonna update curr, so better make sure the next iteration
+        # is going to end the pair
+        in <- skip-whitespace in
+        c <- peek in
+        close-paren?:boolean <- equal c, 41/close-paren
+        assert close-paren?, ['.' must be followed by exactly one expression before ')']
+      }
+      loop
+    }
+    +end-pair
+  }
+]
+
+def skip-whitespace in:&:stream:char -> in:&:stream:char [
+  local-scope
+  load-ingredients
+  {
+    done?:boolean <- end-of-stream? in
+    reply-if done?, 0/null
+    c:char <- peek in
+    space?:boolean <- space? c
+    break-unless space?
+    read in  # skip
+    loop
+  }
+]
+
+def to-text x:&:cell -> out:text [
+  local-scope
+  load-ingredients
+  buf:&:buffer <- new-buffer 30
+  buf <- to-buffer x, buf
+  out <- buffer-to-array buf
+]
+
+def to-buffer x:&:cell, buf:&:buffer -> buf:&:buffer [
+  local-scope
+  load-ingredients
+  # base case: empty cell
+  {
+    break-if x
+    buf <- append buf, [<>]
+    reply
+  }
+  # base case: atom
+  {
+    s:text, atom?:boolean <- maybe-convert *x, atom:variant
+    break-unless atom?
+    buf <- append buf, s
+    reply
+  }
+  # recursive case: pair
+  buf <- append buf, [< ]
+  first:&:cell <- first x
+  buf <- to-buffer first, buf
+  buf <- append buf, [ | ]
+  rest:&:cell <- rest x
+  buf <- to-buffer rest, buf
+  buf <- append buf, [ >]
+]
+
+scenario parse-single-letter-atom [
+  local-scope
+  s:text <- new [a]
+  x:&:cell <- parse s
+  s2:text, 10:boolean/raw <- maybe-convert *x, atom:variant
+  11:@:char/raw <- copy *s2
+  memory-should-contain [
+    10 <- 1  # parse result is an atom
+    11:@:char <- [a]
+  ]
+]
+
+scenario parse-atom [
+  local-scope
+  s:text <- new [abc]
+  x:&:cell <- parse s
+  s2:text, 10:boolean/raw <- maybe-convert *x, atom:variant
+  11:@:char/raw <- copy *s2
+  memory-should-contain [
+    10 <- 1  # parse result is an atom
+    11:@:char <- [abc]
+  ]
+]
+
+scenario parse-list-of-two-atoms [
+  local-scope
+  s:text <- new [(abc def)]
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < abc | < def | <> > >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  x2:&:cell <- rest x
+  s1:text, 11:boolean/raw <- maybe-convert *x1, atom:variant
+  12:boolean/raw <- is-pair? x2
+  x3:&:cell <- first x2
+  s2:text, 13:boolean/raw <- maybe-convert *x3, atom:variant
+  14:&:cell/raw <- rest x2
+  20:@:char/raw <- copy *s1
+  30:@:char/raw <- copy *s2
+  memory-should-contain [
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is an atom
+    12 <- 1  # result.rest is a pair
+    13 <- 1  # result.rest.first is an atom
+    14 <- 0  # result.rest.rest is nil
+    20:@:char <- [abc]  # result.first
+    30:@:char <- [def]  # result.rest.first
+  ]
+]
+
+scenario parse-list-with-extra-spaces [
+  local-scope
+  s:text <- new [ ( abc  def ) ]  # extra spaces
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < abc | < def | <> > >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  x2:&:cell <- rest x
+  s1:text, 11:boolean/raw <- maybe-convert *x1, atom:variant
+  12:boolean/raw <- is-pair? x2
+  x3:&:cell <- first x2
+  s2:text, 13:boolean/raw <- maybe-convert *x3, atom:variant
+  14:&:cell/raw <- rest x2
+  20:@:char/raw <- copy *s1
+  30:@:char/raw <- copy *s2
+  memory-should-contain [
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is an atom
+    12 <- 1  # result.rest is a pair
+    13 <- 1  # result.rest.first is an atom
+    14 <- 0  # result.rest.rest is nil
+    20:@:char <- [abc]  # result.first
+    30:@:char <- [def]  # result.rest.first
+  ]
+]
+
+scenario parse-list-of-more-than-two-atoms [
+  local-scope
+  s:text <- new [(abc def ghi)]
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < abc | < def | < ghi | <> > > >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  x2:&:cell <- rest x
+  s1:text, 11:boolean/raw <- maybe-convert *x1, atom:variant
+  12:boolean/raw <- is-pair? x2
+  x3:&:cell <- first x2
+  s2:text, 13:boolean/raw <- maybe-convert *x3, atom:variant
+  x4:&:cell <- rest x2
+  14:boolean/raw <- is-pair? x4
+  x5:&:cell <- first x4
+  s3:text, 15:boolean/raw <- maybe-convert *x5, atom:variant
+  16:&:cell/raw <- rest x4
+  20:@:char/raw <- copy *s1
+  30:@:char/raw <- copy *s2
+  40:@:char/raw <- copy *s3
+  memory-should-contain [
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is an atom
+    12 <- 1  # result.rest is a pair
+    13 <- 1  # result.rest.first is an atom
+    14 <- 1  # result.rest.rest is a pair
+    15 <- 1  # result.rest.rest.first is an atom
+    16 <- 0  # result.rest.rest.rest is nil
+    20:@:char <- [abc]  # result.first
+    30:@:char <- [def]  # result.rest.first
+    40:@:char <- [ghi]  # result.rest.rest
+  ]
+]
+
+scenario parse-nested-list [
+  local-scope
+  s:text <- new [((abc))]
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < < abc | <> > | <> >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  11:boolean/raw <- is-pair? x
+  x2:&:cell <- first x1
+  s1:text, 12:boolean/raw <- maybe-convert *x2, atom:variant
+  13:&:cell/raw <- rest x1
+  14:&:cell/raw <- rest x
+  20:@:char/raw <- copy *s1
+  memory-should-contain [
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is a pair
+    12 <- 1  # result.first.first is an atom
+    13 <- 0  # result.first.rest is nil
+    14 <- 0  # result.rest is nil
+    20:@:char <- [abc]  # result.first.first
+  ]
+]
+
+scenario parse-nested-list-2 [
+  local-scope
+  s:text <- new [((abc) def)]
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < < abc | <> > | < def | <> > >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  11:boolean/raw <- is-pair? x
+  x2:&:cell <- first x1
+  s1:text, 12:boolean/raw <- maybe-convert *x2, atom:variant
+  13:&:cell/raw <- rest x1
+  x3:&:cell <- rest x
+  x4:&:cell <- first x3
+  s2:text, 14:boolean/raw <- maybe-convert *x4, atom:variant
+  15:&:cell/raw <- rest x3
+  20:@:char/raw <- copy *s1
+  30:@:char/raw <- copy *s2
+  memory-should-contain [
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is a pair
+    12 <- 1  # result.first.first is an atom
+    13 <- 0  # result.first.rest is nil
+    14 <- 1  # result.rest.first is an atom
+    15 <- 0  # result.rest.rest is nil
+    20:@:char <- [abc]  # result.first.first
+    30:@:char <- [def]  # result.rest.first
+  ]
+]
+
+# todo: uncomment these tests after we figure out how to continue tests after
+# assertion failures
+#? scenario parse-error [
+#?   local-scope
+#?   s:text <- new [(]
+#? #?   hide-errors
+#?   x:&:cell <- parse s
+#? #?   show-errors
+#?   trace-should-contain [
+#?     error: unbalanced '(' in expression
+#?   ]
+#? ]
+#? 
+#? scenario parse-error-after-element [
+#?   local-scope
+#?   s:text <- new [(abc]
+#? #?   hide-errors
+#?   x:&:cell <- parse s
+#? #?   show-errors
+#?   trace-should-contain [
+#?     error: unbalanced '(' in expression
+#?   ]
+#? ]
+
+scenario parse-dotted-list-of-two-atoms [
+  local-scope
+  s:text <- new [(abc . def)]
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < abc | def >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  x2:&:cell <- rest x
+  s1:text, 11:boolean/raw <- maybe-convert *x1, atom:variant
+  s2:text, 12:boolean/raw <- maybe-convert *x2, atom:variant
+  20:@:char/raw <- copy *s1
+  30:@:char/raw <- copy *s2
+  memory-should-contain [
+    # parses to < abc | def >
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is an atom
+    12 <- 1  # result.rest is an atom
+    20:@:char <- [abc]  # result.first
+    30:@:char <- [def]  # result.rest
+  ]
+]
+
+scenario parse-dotted-list-of-more-than-two-atoms [
+  local-scope
+  s:text <- new [(abc def . ghi)]
+  x:&:cell <- parse s
+  trace-should-contain [
+    app/parse: < abc | < def | ghi > >
+  ]
+  10:boolean/raw <- is-pair? x
+  x1:&:cell <- first x
+  x2:&:cell <- rest x
+  s1:text, 11:boolean/raw <- maybe-convert *x1, atom:variant
+  12:boolean/raw <- is-pair? x2
+  x3:&:cell <- first x2
+  s2:text, 13:boolean/raw <- maybe-convert *x3, atom:variant
+  x4:&:cell <- rest x2
+  s3:text, 14:boolean/raw <- maybe-convert *x4, atom:variant
+  20:@:char/raw <- copy *s1
+  30:@:char/raw <- copy *s2
+  40:@:char/raw <- copy *s3
+  memory-should-contain [
+    10 <- 1  # parse result is a pair
+    11 <- 1  # result.first is an atom
+    12 <- 1  # result.rest is a pair
+    13 <- 1  # result.rest.first is an atom
+    14 <- 1  # result.rest.rest is an atom
+    20:@:char <- [abc]  # result.first
+    30:@:char <- [def]  # result.rest.first
+    40:@:char <- [ghi]  # result.rest.rest
+  ]
+]
+
+## convert tree of cells to mu text
+
+def to-mu in:&:cell -> out:text [
+  local-scope
+  load-ingredients
+  buf:&:buffer <- new-buffer 30
+  buf <- to-mu in, buf
+  out <- buffer-to-array buf
+]
+
+def to-mu in:&:cell, buf:&:buffer -> buf:&:buffer, result-name:text [
+  local-scope
+  load-ingredients
+  # null cell? no change.
+  # pair with all atoms? gensym a new variable
+  # pair containing other pairs? recurse
+  result-name <- copy 0
+]