Add boot3 to take advantage of some boot2 simplifications

1 files changed, 116 insertions, 0 deletions

diff --git a/src/bootstrap/boot3.bqn b/src/bootstrap/boot3.bqn
new file mode 100644
index 00000000..ccbd2d28
--- /dev/null
+++ b/src/bootstrap/boot3.bqn
@@ -0,0 +1,116 @@
+# Compiler simplified three times
+# Suitable for compiling twice-simplified compiler
+# Probably not any easier to compile, but it's shorter
+{
+  charSet←∾chars←⟨
+    "+-×÷⋆√⌊⌈|¬∧∨<>≠=≤≥≡≢⊣⊢⥊∾≍⋈↑↓↕«»⌽⍉/⍋⍒⊏⊑⊐⊒∊⍷⊔!" # Function
+    "˙˜˘¨⌜⁼´˝`"           # 1-modifier
+    "∘○⊸⟜⌾⊘◶⎉⚇⍟⎊"         # 2-modifier
+    "⋄,"∾lf←@+10          # Separator
+    "←↩"                  # Gets
+    "(){}⟨⟩"              # Bracket
+    "𝕊𝕩𝕨"                 # Input
+    "¯π∞"                 # Numeric
+    (⊑"0")+↕10            # Digit
+    ⥊"aA"+⌜↕na←26         # Alphabetic
+    " "                   # Whitespace
+    sc←@+⟨35,34,64⟩       # Preprocessed characters: hash, double quote, @
+  ⟩
+  cm←((0»+`)⋈¨⊢)cgl←≠¨chars
+  bS←3⊑cm⋄bG←4⊑cm⋄bB←5⊑cm⋄bI←6⊑cm⋄bN←7⊑cm⋄bA←9⊑cm⋄bW←10⊑cm
+  sep←⊑bS
+  vi←⊑bN  # Start of identifier numbering
+  charRole←∾cgl⥊¨⟨1,2,3,¯1,¯3,⟨¯1,0⟩,⟨1,0,0⟩,0,0,26/⟨0,1⟩,4,0⟩
+  TT←⌈`× ⋄ IT←(↕≠)TT⊢ ⋄ I1T←(1+(↕≠))TT⊢
+
+  # Comments and strings
+  s←≠`dd←𝕩=1⊑sc⋄ss←s∧dd                     # Strings; string start
+  f←s<(I1T s<𝕩=⊑sc)≤I1T𝕩=lf                 # Filter comments
+  chr←@¨ci←/f∧𝕩=2⊑sc                        # Characters (indices ci)
+  str←𝕩⊔˜1-˜(+`ss∾1)×(ss<s)∾1               # Strings
+
+  # Extract words: identifiers and numbers
+  t←charSet⊐f/𝕩                             # Tokens
+  r←t⊏charRole                              # Role
+  l←(t≥⊑bN)∧t<⊑bW⋄w←l>»l                    # Word chars l, start w
+  wi←(⊑bA)≤w/t                              # Type: 0 number, 1 identifier
+  t↩t-na×l∧r=1                              # Case-insensitive
+  n←l∧(+`w)⊏0∾¬wi                           # Number mask
+  ide←(1-˜(l>n)×+`w>n)⊔t⊏charSet            # Identifiers
+
+  # Numbers, at most 2 digits
+  nt←((⊢∨«)0∾n)/0∾t×l                       # Number tokens separated by 0
+  nn←nt=⊑bN⋄m←¬nn∨0=nt                      # Mask for ¯; digits
+  nl←(0∾⟨π,∞⟩∾↕10)⊏˜m×nt-⊑bN                # Digit lookup
+  ns←⟨1,¯1⟩⊏˜(m>»m)/»nn                     # Negate if ¯
+  num←ns×(m>«m)/nl+10×»nl                   # Numeric values
+
+  # Deduplicate literals and identifiers; other cleanup
+  # Identifiers then literal tokens are numbered starting at vi
+  ki←((⍒wi)⊏/w)∾(ci∾/ss)⊏+`»f               # Indices in t
+  k←⟨ide,⟨⟩,num,chr,str⟩                    # Constants
+  k↩k/¨˜(⊢>¯1»⌈`)¨j←⊐¨k                     # IDs j into uniques k
+  wr←w∨¬l∨t=⊑bW⋄r↩wr/r⋄c←≠t
+  t↩wr/(c↑⍋(⊢+c×⊒)ki∾↕c)⊏(∾j++`vi»≠¨k)∾t    # Add IDs; remove words/whitespace
+  t↩t-(t<+´bS)×(⊢×0≤⊢)t-⊑bS                 # Separators are equivalent
+  pb←≠`1¨sb←¯1↓1↓/1(∾≠∾˜)t=sep              # Separator group boundaries (excludes leading and trailing)
+  eb←⟨3,5⟩+⊑bB                              # End brackets that allow separators
+  sk←sb/˜pb>(⊢∨«)eb∊˜pb+(sb-pb)⊏t           # Keep the first of each group that's not just inside a bracket
+  sr←((≠t)↑/⁼sk)∨t≠sep⋄r↩sr/r⋄t↩sr/t        # Remove the rest
+  𝕩↩t⋄nv←≠⊑k
+  # End of tokenization!
+
+  # Bracket roles
+  # Open brackets initially have role ¯1 and closed ones have role 0
+  gb←⍋+`p←(¯1-2×r)×(𝕩≥⊑bB)∧𝕩<+´bB           # Paren (actually any bracket type) depth and grade
+  r↩r+𝕩=3+⊑bB                               # Assume blocks are functions
+  cp←𝕩=1+⊑bB                                # Closed paren
+  ir←((IT cp≤⊢)⊏⊢)0<r                       # Role of the expression ending at each position
+  r↩r+cp×»ir                                # Roles at cp were 0; set them now
+
+  # Reverse each expression: *more* complicated than it looks
+  rev←⍋+`¯1↓(¯1∾gb)((⍋⊣)⊏((⍋⊢)⊏⊣)¬⊏˜)⍋(+`+⊢)1∾gb⊏r=¯1
+
+  # Lexical resolution, no nesting
+  # The last-use indicator ⌽∊⌽ii has to be done in rev ordering which
+  # prevents some improvements
+  rx←rev⊏𝕩
+  iv←/(rx≥⊑bI)∧rx<vi+nv                     # Variable indices
+  vv←(iv⊏rx)-vi                             # Variable name
+  ii←3↓⊐(¯3+↕3)∾vv                          # Slot within frame
+  va←iv⊏»rx⋄vb←(va≥⊑bG)∧va<+´bG             # Variable assignment, if it's there
+  idor←∾3/⟨iv⟩                              # Identifier bytecode ordering
+  idoc←⟨32+vb+2×vb<⌽∊⌽ii,0¨ii,ii⟩           # Identifier bytecode: instruction, depth, slot
+  dn←⟨⟨⟩,(va=⊑bG)/vv⟩                       # Identifier name ID, per-block
+
+  # Parsing
+  gr←rev⊏˜g←⍋+`rev⊏p                        # Order by bracket depth
+  𝕩↩gr⊏𝕩⋄r↩gr⊏r⋄ir↩gr⊏ir
+  at←/aa←»a←¯3=r                            # Assignment target
+  ao←(a/𝕩)-⊑bG                              # Assignment opcode
+  tr←ir⊏˜IT»ps←a<r<0                        # tr: train or modifier expression, ps: part separator
+  oa←⌽/op←r=2                               # op: active modifiers; op: mod or right operand
+  xs←𝕩=sep⋄fo←𝕩=2+⊑bB                       # Separators, function open {
+  ls←xs∧(IT fo)<IT lo←𝕩=4+⊑bB               # List Separators: after ⟨lo, not {fo
+  ta←tr∧2(>∨|)ps(⊢-TT)+`¬op                 # Train argument (first-level)
+  fa←/(ta∨op∨(«∨⊢)ps<aa)<(r=1)∨»op          # Active functions
+  dy←fa⊏«(tr∧r≥0)∨op<r=0                    # Dyadic
+  pr←𝕩⊏˜pi←/𝕩<sep⋄ob←pr⊏/¯1(⊢-»)u←⍷∧pr      # Objects to be loaded
+  cn←pi∾lt←/𝕩≥cl←vi+nv⋄ob↩ob∾(cl-˜≠u)+lt⊏𝕩  # Constants
+  bk←(𝕩=3+⊑bB)/⍋g                           # Block loads
+  lb←/𝕩=5+⊑bB                               # List starts
+  ll←(¬lo/1«ps)+(⊢-»)1↓(lo∾1)/+`ls∾0        # List Length
+  dr←/xs>ls⋄rt←/fo                          # Drop (block separator) and return
+  os←⌽(↕≠op)(⊣-TT)⌽¬op                      # Operator skip: distance rightward to derived function start
+  fl←(⊢+dy×⊢⊏os˙)fa+dy                      # Function application site
+
+  # Object code generation: numbers oc ordered by source location (after rev) oi
+  fsc←3×fx←↕2                               # Body immediacy ¬fx, special name count
+  or←⍋idor∾g⊏˜∾⟨cn,cn,bk,bk,2/lb,at,dr,oa+1⌈oa⊏os,fl,rt⟩
+  oc←or⊏∾idoc∾⟨0¨cn,ob,1¨bk,1+↕≠bk,⥊⍉(11+lb⊏aa)≍ll,48+ao,6¨dr
+               24+oa⊏r,16+dy+4×fa⊏tr,¯1↓rc←7¨fx⟩
+  # Output
+  fz←⟨0¨fx,¬fx,↕≠fx⟩                        # Per-function data
+  cz←⟨/1∾or≥(≠oc)-≠rt,fsc+≠¨dn,dn,0¨¨dn⟩    # Per-body data
+  ⟨oc∾¯1⊑rc,∾⟨u⊏𝕨⟩∾1↓k,<˘⍉>fz,<˘⍉>cz⟩       # Overall output
+}