billhails · billhails · Jun 7, 2026 · May 22, 2026 · May 22, 2026 · May 22, 2026
diff --git a/.gitignore b/.gitignore
@@ -37,6 +37,7 @@ coverage.info
 coverage_filtered.info
 test_output.log
 .github/skills
+.codegraph
 
 # Refactoring testing baseline (optional: remove this line to track in git)
 test_baseline/
diff --git a/Makefile b/Makefile
@@ -2,7 +2,7 @@
 list-cores test indent indent-src indent-generated docs \
 install-sqlite3 install-raylib coverage extracov view-coverage \
 coverage-target test-a test-fail test-sh test-c test-unit test-b test-big-c help \
-test-gfx test-gfx-stress establish-baseline test-refactoring update-baseline clean-baseline \
+test-rewrite test-gfx test-gfx-stress establish-baseline test-refactoring update-baseline clean-baseline \
 scratch bench-regex-cache rebuild-default rebuild-raylib
 
 # pass on the command line, i.e. `make test MODE=prod`
@@ -97,6 +97,23 @@ EXTRA_TARGETS= \
 	$(GENDIR)/cps_kont_impl.h \
 	$(GENDIR)/cps_kont_impl.c
 
+GENERATED_BOOTSTRAP= \
+	$(EXTRA_H_TARGETS) \
+	$(EXTRA_OBJTYPES_H_TARGETS) \
+	$(EXTRA_DEBUG_H_TARGETS) \
+	$(GENDIR)/UnicodeData.inc \
+	$(GENDIR)/UnicodeCasing.inc \
+	$(GENDIR)/UnicodeDigits.inc \
+	$(GENDIR)/UnicodeNumbers.inc \
+	$(GENDIR)/anf_kont.h \
+	$(GENDIR)/anf_kont_objtypes.h \
+	$(GENDIR)/anf_kont_debug.h \
+	$(GENDIR)/anf_kont_impl.inc \
+	$(GENDIR)/cps_kont.h \
+	$(GENDIR)/cps_kont_objtypes.h \
+	$(GENDIR)/cps_kont_debug.h \
+	$(GENDIR)/cps_kont_impl.h
+
 MAIN=$(SRCDIR)/main.c
 PREAMBLE=$(GENDIR)/preamble.c
 CFILES=$(filter-out $(MAIN), $(wildcard $(SRCDIR)/*.c))
@@ -153,15 +170,15 @@ FN_BFILES=$(patsubst $(FNDIR)/%,$(TMPDIR)/%,$(patsubst %.fn,%.fnc,$(FN_FILES)))
 FN_OFILES=$(patsubst %.c,%.o,$(FN_CFILES))
 FN_BINARIES=$(patsubst %.o,%,$(FN_OFILES))
 
-TARGET_ARGS=--include=fn --flat-closure
+TARGET_ARGS=--include=fn --assertions-accumulate
 
 $(TEST_FN_CFILES): $(TMPDIR)/%.c: $(TEST_FN_DIR)/%.fn $(TARGET) | $(TMPDIR)
-	$(TARGET) $(TARGET_ARGS) --target-c=$@~ $<  && mv $@~ $@
+	$(TARGET) $(TARGET_ARGS) --flat-closure --target-c=$@~ $<  && mv $@~ $@
 	indent $@
 	rm -f $@~
 
 $(FN_CFILES): $(TMPDIR)/%.c: $(FNDIR)/%.fn $(TARGET) | $(TMPDIR)
-	$(TARGET) $(TARGET_ARGS) --target-c=$@~ $< && mv $@~ $@
+	$(TARGET) $(TARGET_ARGS) --flat-closure --target-c=$@~ $< && mv $@~ $@
 	indent $@
 	rm -f $@~
 
@@ -172,10 +189,10 @@ $(FN_BFILES): $(TMPDIR)/%.fnc: $(FNDIR)/%.fn $(TARGET) | $(TMPDIR)
 	$(TARGET) --binary-out=$@~ $<  && mv $@~ $@
 
 $(TEST_FN_SFILES): $(TMPDIR)/%.scm: $(TEST_FN_DIR)/%.fn $(TARGET) | $(TMPDIR)
-	$(TARGET) $(TARGET_ARGS) --target-c --dump-inline-f $<  > $@~ && mv $@~ $@
+	$(TARGET) $(TARGET_ARGS) --flat-closure --target-c --dump-inline-f $<  > $@~ && mv $@~ $@
 
 $(FN_SFILES): $(TMPDIR)/%.scm: $(FNDIR)/%.fn $(TARGET) | $(TMPDIR)
-	$(TARGET) $(TARGET_ARGS) --target-c --dump-inline-f $<  > $@~ && mv $@~ $@
+	$(TARGET) $(TARGET_ARGS) --flat-closure --target-c --dump-inline-f $<  > $@~ && mv $@~ $@
 
 $(FN_OFILES) $(TEST_FN_OFILES): %.o: %.c
 	$(LAXCC) $(INCLUDE_PATHS) -c $< -o $@
@@ -240,7 +257,7 @@ Double \
 Control
 EXTRA_INDENT_ARGS=$(patsubst %,-T %,$(EXTRA_TYPES))
 
-include $(ALL_DEP)
+-include $(ALL_DEP)
 
 $(PREAMBLE): $(PREAMBLE_SRC) | $(GENDIR)
 	tools/make-preamble.sh
@@ -291,61 +308,49 @@ $(GENDIR)/cps_kont_impl.c: tools/cps_continuations.yaml $(GENDEPS) $(SRCDIR)/pri
 $(EXTRA_DOCS): $(DOCDIR)/%.md: $(SRCDIR)/%.yaml $(GENDEPS) $(SRCDIR)/primitives.yaml | $(DOCDIR)
 	$(MAKE_AST) $< md > $@~ && mv $@~ $@
 
-.generated: $(EXTRA_TARGETS)
-	touch $@
-
 tags: $(SRCDIR)/* $(EXTRA_TARGETS)
 	ctags $(SRCDIR)/* $(EXTRA_TARGETS)
 
 xref: $(SRCDIR)/* $(EXTRA_TARGETS)
 	ctags -x $(SRCDIR)/* $(EXTRA_TARGETS) > $@
 
-$(MAIN_OBJ) $(OBJ): $(OBJDIR)/%.o: $(SRCDIR)/%.c | $(OBJDIR)
-	$(CC) $(INCLUDE_PATHS) -c $< -o $@
-
-$(EXTRA_OBJ) $(PREAMBLE_OBJ): $(OBJDIR)/%.o: $(GENDIR)/%.c | $(OBJDIR)
-	$(CC) $(INCLUDE_PATHS) -c $< -o $@
-
-$(TEST_OBJ): $(OBJDIR)/%.o: $(TSTDIR)/src/%.c | $(OBJDIR)
-	$(LAXCC) $(INCLUDE_PATHS) -c $< -o $@
-
-$(MAIN_DEP) $(DEP): $(DEPDIR)/%.d: $(SRCDIR)/%.c .generated | $(DEPDIR)
-	$(CC) $(INCLUDE_PATHS) -MM -MT $(patsubst $(DEPDIR)/%,$(OBJDIR)/%,$(patsubst %.d,%.o,$@)) -o $@ $<
+$(MAIN_OBJ) $(OBJ): $(OBJDIR)/%.o: $(SRCDIR)/%.c | $(OBJDIR) $(DEPDIR) $(GENERATED_BOOTSTRAP)
+	$(CC) $(INCLUDE_PATHS) -MMD -MP -MF $(DEPDIR)/$*.d -MT $@ -c $< -o $@
 
-$(EXTRA_DEP) $(PREAMBLE_DEP): $(DEPDIR)/%.d: $(GENDIR)/%.c .generated | $(DEPDIR)
-	$(CC) $(INCLUDE_PATHS) -MM -MT $(patsubst $(DEPDIR)/%,$(OBJDIR)/%,$(patsubst %.d,%.o,$@)) -o $@ $<
+$(EXTRA_OBJ) $(PREAMBLE_OBJ): $(OBJDIR)/%.o: $(GENDIR)/%.c | $(OBJDIR) $(DEPDIR) $(GENERATED_BOOTSTRAP)
+	$(CC) $(INCLUDE_PATHS) -MMD -MP -MF $(DEPDIR)/$*.d -MT $@ -c $< -o $@
 
-$(TEST_DEP): $(DEPDIR)/%.d: $(TSTDIR)/src/%.c .generated | $(DEPDIR)
-	$(CC) $(INCLUDE_PATHS) -MM -MT $(patsubst $(DEPDIR)/%,$(OBJDIR)/%,$(patsubst %.d,%.o,$@)) -o $@ $<
+$(TEST_OBJ): $(OBJDIR)/%.o: $(TSTDIR)/src/%.c | $(OBJDIR) $(DEPDIR) $(GENERATED_BOOTSTRAP)
+	$(LAXCC) $(INCLUDE_PATHS) -MMD -MP -MF $(DEPDIR)/$*.d -MT $@ -c $< -o $@
 
-test: test-unit test-a test-b test-sh test-fail
+test: test-unit test-a test-b test-sh test-fail test-rewrite
 	@echo "All tests passed."
 
-test-unit: all $(TEST_TARGETS)
-	for t in $(TEST_TARGETS) ; do echo '***' $$t '***' ; $$t || exit 1 ; done
+test-unit: $(TEST_TARGETS)
+	set -x; for t in $(TEST_TARGETS) ; do $$t || exit 1 ; done
 	@echo "All unit tests passed."
 
 test-a: all
-	for t in $(TSTDIR)/fn/test_*.fn ; do echo '***' $$t '***' ; ./$(TARGET) --include=fn --assertions-accumulate $$t || exit 1 ; done
+	set -x; for t in $(TSTDIR)/fn/test_*.fn ; do $(TARGET) $(TARGET_ARGS) $$t || exit 1 ; done
 	@echo "All a tests passed."
 
 test-sh: all
-	for t in $(TSTDIR)/sh/*.sh ; do [ -e $$t ] || continue ; echo '***' $$t '***' ; bash $$t || exit 1 ; done
+	set -x ; for t in $(TSTDIR)/sh/*.sh ; do bash $$t || exit 1 ; done
 	@echo "All sh tests passed."
 
 test-fail: all
-	for t in $(TSTDIR)/fn/fail_*.fn ; do echo '***' $$t '***' ; ! ./$(TARGET) --include=fn --assertions-accumulate $$t >/dev/null 2>&1 || exit 1 ; done
+	set -x ; for t in $(TSTDIR)/fn/fail_*.fn ; do ! ./$(TARGET) $(TARGET_ARGS) $$t >/dev/null 2>&1 || exit 1 ; done
 	@echo "All negative tests passed."
 
 test-c: all $(TEST_FN_BINARIES)
-	@for t in $(TEST_FN_BINARIES) ; do echo $$t ; $$t || exit 1 ; done
+	set -x ; for t in $(TEST_FN_BINARIES) ; do $$t || exit 1 ; done
 	@echo All generated C tests pass
 
 test-big-c: all $(TMPDIR)/test_harness
 	$(TMPDIR)/test_harness
 
 test-b: all
-	@for t in $(TEST_FN_FILES) ; do set -x; $(TARGET) $(TARGET_ARGS) --target-b $$t || exit 1 ; done
+	set -x; for t in $(TSTDIR)/fn/test_*.fn ; do $(TARGET) $(TARGET_ARGS) --flat-closure --target-b $$t || exit 1 ; done
 	@echo All B-code tests pass
 
 test-gfx: all
@@ -357,6 +362,10 @@ test-gfx-stress: all
 	@for t in $(TSTDIR)/fn/test_gfx_shader_reload_smoke.fn $(TSTDIR)/fn/test_gfx_resource_churn_smoke.fn ; do echo '***' $$t '***' ; ./$(TARGET) --include=fn --assertions-accumulate --stress-gc $$t || exit 1 ; done
 	@echo "All gfx stress smoke tests passed."
 
+test-rewrite: all
+	set -x; for t in fn/rewrite/tests/test_*.fn ; do $(TARGET) $(TARGET_ARGS) --flat-closure --target-b $$t || exit 1 ; done
+	@echo All rewrite tests pass
+
 $(TEST_TARGETS): $(TSTDIR)/%: $(OBJDIR)/%.o $(ALL_OBJ)
 	$(CC) -o $@ $< $(ALL_OBJ) $(LIBS)
 
@@ -398,7 +407,7 @@ realclean: clean
 	rm -rf tags xref $(UNIDIR)
 
 clean: deps
-	rm -rf $(BINDIR) $(OBJDIR) callgrind.out.* $(GENDIR) $(TEST_TARGETS) .typedefs $(SRCDIR)/*~ .generated gmon.out *.fnc core.* coverage_html coverage_report.txt gcov_output *.gcda *.gcno coverage.info coverage_filtered.info test_output.log $(TEST_FN_CFILES) $(TEST_FN_OFILES) $(TEST_FN_BINARIES) $(TEST_FN_SFILES) $(TMPDIR)
+	rm -rf $(BINDIR) $(OBJDIR) callgrind.out.* $(GENDIR) $(TEST_TARGETS) $(SRCDIR)/*~ gmon.out *.fnc core.* coverage_html coverage_report.txt gcov_output *.gcda *.gcno coverage.info coverage_filtered.info test_output.log $(TEST_FN_CFILES) $(TEST_FN_OFILES) $(TEST_FN_BINARIES) $(TEST_FN_SFILES) $(TMPDIR)
 	$(MAKE) -C scratch clean
 
 rebuild-default:
@@ -441,18 +450,6 @@ profile-parse: all
 leak-check: all
 	valgrind --leak-check=full ./$(TARGET) $(FNDIR)/$(PROF_SRC).fn
 
-indent: indent-src indent-generated
-
-indent-src: .typedefs .indent.pro
-	indent `cat .typedefs | sort -u | xargs` $(EXTRA_INDENT_ARGS) $(SRCDIR)/*.[ch]
-	rm -f $(SRCDIR)/*~
-
-indent-generated: .typedefs .indent.pro
-	indent `cat .typedefs | sort -u | xargs` $(EXTRA_INDENT_ARGS) $(GENDIR)/*.[ch]
-	rm -f $(GENDIR)/*~
-
-.typedefs: .generated
-
 list-cores:
 	@ls -rt1 /var/lib/apport/coredump/* | tail -1
 

diff --git a/docs/TODO.md b/docs/TODO.md
@@ -2,40 +2,33 @@
 
 More of a wish-list than a hard and fast plan.
 
+* Fn/Rewrite.
+  * Add an interpreter for the final IR.
+  * Add a parser and AST.
+  * Type Checking.
+  * etc.
 * More folding opportunities.
-  * fold boolean expressions `true and false => false`.
-    * tricky because `and`, `or` etc. are not primitive, they are lazy operators defined in terms of `if` in the preamble.
-  * fold comparisons `a == a => true`, `a >= a => true` etc. DONE
-  * fold constant conditions `(if true a b) => a`. DONE
-    * This solves the boolean expression folding problem, after β/η-reduction:
-      * `true and false => (if true false false) => false`
-  * fold duplicate condition branches `(if x a a) => a`.
+  * Fold duplicate condition branches `(if x a a) => a`.
 * Continuations.
-  * Reinstate `cut` (prunes current back continuation). DONE
   * Implement delimited continuations.
-* Regular Expressions.
-  * Enlist the new regex engine to support the core Pratt scanner.
+    * delimit/capture instead of reset/shift?
 * Types.
   * Consider type classes as a general solution to `EQ <type>`, `map` etc.
   * Records should create accessor functions for each tag.
     * if there is only one type variant.
-  * extend the `typedef` keyword.
-    * `typedef container(#t);` is shorthand for `typedef container(#t) { container(#t) };`
-    * `typedef container(char);` is shorthand for `typedef container { container(char) };`
-    * no additional AST should be required, or if it is it gets immediately desugared so doesn't leak downstream.
 * Namespaces.
-  * We want `import <ns> function <x>` and `import <ns> functions`. DONE mostly.
-  * And `import <ns> typedef <x>` and `import <ns> typedefs`.
+  * `import <ns> typedef <x>` and `import <ns> typedefs`.
 * Parser.
-  * re-elist the now-available `macro` keyword for proper syntactic extensibility. DONE
-    * if/then/else => `(fn { (true) {then} (false) {else} }(if))` (we already do this but hard-coded in the parser).
-    * `do` notation for monads.
+  * if/then/else => `(fn { (true) {then} (false) {else} }(if))` (we already do this but hard-coded in the parser).
+  * `do` notation for monads.
 * Memory Management.
   * Replace mark and sweep GC with a generational stop and copy.
 * Pipeline.
   * Re-order Type Checking before TPMC.
   * Target LLVM.
 * Generate.
+  * Add a generator for equivalent F♮ `typedef`s to facilitate `fn/rewrite/`.
+    * Will need F♮ support for hashes, symbols arrays etc.
   * Move all signatures into `signature_helper.py`, not just the shared ones.
 * More numbers.
   * Vectors.
@@ -51,7 +44,6 @@ More of a wish-list than a hard and fast plan.
     * does `a / 6` match `2 / 3` and bind `a` to `4`.
     * match would fail if the actual argument is not integer or rational.
     * `b` would be bound to `1` if the argument was an integer.
-    * can't allow arbitrary ops and combinations because i.e. `a * b` can't uniquely determine `a` and `b`, and `a ** 2` would require `a` to be bound to the square root of the actual argument.
   * allow unpacking of the real and imaginary parts of a complex number in patterns.
     * another special case: `a + b`, `b` would be bound to `0i` if the actual argument  is not complex.
   * `mathutils.fn` for `factorial`, `gcd`, `lcm`, `fib`, `pi` etc.

diff --git a/docs/delimited_continuations_notes.md b/docs/delimited_continuations_notes.md
@@ -0,0 +1,140 @@
+# Delimited Continuations
+
+Standared `shift/reset` semantics:
+
+* `reset (1 + shift k { 10 + k(2) }) = 13`
+* `reset (1 + shift k { 2 }) = 2`
+* `reset (1 + shift k { k(2) }) = 3`
+* `reset (1 + shift k { k(2) + k(3) }) = 7`
+* `reset (1 + shift k { 100 + k(k(2)) }) = 104`
+* `reset (1 + shift k { 100 + k(2) + 1000 }) = 1103`
+* `reset (1 + (reset (2 + shift k { k(3) }))) = 6`
+* `reset (1) = 1`
+* `reset (1 + shift k { 2 }) = 2`
+* `1 + reset (shift k { 2 }) = 3`
+
+## Difference between `shift/reset` and `control/prompt`
+
+* `reset ((1 + shift k { 2 + k(3) }) + shift h { h(4) + h(5) }) = 19`
+* `prompt ((1 + control k { 2 + k(3) }) + control h { h(4) + h(5) }) = 21`
+
+### The `shift/reset` example
+
+* `reset ((1 + shift k { 2 + k(3) }) + shift h { h(4) + h(5) }) = 19`
+
+To understand that `shift/reset` example first, let
+
+```fn
+T = reset (
+    (1 + shift k { 2 + k(3) })
+  + shift h { h(4) + h(5) }
+)
+```
+
+The first `shift` captures the context:
+
+```fn
+E1 = (1 + [ ]) + shift h { h(4) + h(5) }
+```
+
+So under `shift/reset`:
+
+```txt
+k(v) = reset( (1 + v) + shift h { h(4) + h(5) } )
+//     ^^^^^
+```
+
+That extra `reset` is the crucial part. So the term becomes:
+
+```fn
+T = reset( 2 + k(3) )
+  = reset( 2 + reset( (1 + 3) + shift h { h(4) + h(5) } ) )
+```
+
+Now look at the inner `reset`:
+
+```fn
+  reset( (1 + 3) + shift h { h(4) + h(5) } )
+= reset( 4       + shift h { h(4) + h(5) } )
+```
+
+`h` captures only
+
+```fn
+E2 = 4 + [ ]
+```
+
+so
+
+```fn
+h(v) = reset(4 + v)
+```
+
+Hence:
+
+```fn
+h(4) = 8
+h(5) = 9
+```
+
+so the inner reset is:
+
+```fn
+  reset( h(4) + h(5) )
+= reset( 8 + 9 )
+= 17
+```
+
+and therefore the whole term is:
+
+```fn
+reset( 2 + 17 ) = 19
+```
+
+## The Difference
+
+```fn
+shift/reset:
+reset (
+    (1 + shift k { 2 + k(3) })
+  + shift h { h(4) + h(5) }
+)
+```
+
+```fn
+control/prompt:
+prompt (
+    (1 + control k { 2 + k(3) })
+  + control h { h(4) + h(5) }
+)
+```
+
+### shift/reset
+
+```fn
+reset          ((1 + shift k { 2 + k(3) }) + shift h { h(4) + h(5) }) = 19
+E1 =            (1 + [                  ]) + shift h { h(4) + h(5) }
+k(v) =    reset((1 + v                   ) + shift h { h(4) + h(5) })
+reset(2 + reset((1 + 3                   ) + shift h { h(4) + h(5) }))
+E2 =             4                         + [                     ]
+h(v) =     reset(4                         + v)
+h(4) = 8
+h(5) = 9
+inner reset: 17
+final result: 19
+```
+
+### control/prompt
+
+```fn
+prompt     ((1 + control k { 2 + k(3) }) + control h { h(4) + h(5) }) = 21
+E1 =        (1 + [                    ]) + control h { h(4) + h(5) }
+k(v) =      (1 + v                     ) + control h { h(4) + h(5) }
+prompt(2 + ((1 + 3                     ) + control h { h(4) + h(5) }))
+prompt(6                                 + control h { h(4) + h(5) })
+E2 =   6                                 + [                       ]
+h(v) = 6                                 + v
+h(4) = 10
+h(5) = 11
+final result: 21
+```