c317d683fb
Three fixes that lift seven test programs from skipped to passing, bringing the AOT compiler harness from 56/56 to 63/63. - Unnumbered programs (compiler_main.c): src/compiler_main.c skipped any line that didn't start with a digit, so direct-mode .bas files like hello.bas, math_ops.bas, string_ops.bas (no line numbers) failed with "No program lines found". load_file now auto-assigns line numbers (last_num + 10) to unnumbered lines, with overflow protection at line 65520. - String concatenation in PRINT (codegen.c): emit_str_atom had a broken concat loop that emitted "; _cat = gw_str_concat(&... _cat.sval ...)" — _cat was never declared, so any program with a string-literal concat in PRINT (like PRINT "ABC" + "DEF") failed to link. Concat is properly handled by emit_str_expr's outer loop; remove the dead/broken code in the atom. Fixes string_ops.bas. - Transcendental result type (codegen.c): peek_expr_type returned VT_DBL for ATN/LOG/EXP/VAL, so PRINT formatted them with 15-digit double precision (e.g. 3.141592653589793) while real GW-BASIC and the interpreter format the single-precision result as 3.141593. Real GW-BASIC's transcendentals are single-precision; only CDBL forces double. Demote ATN/LOG/EXP/VAL to VT_SNG; CDBL stays VT_DBL. Fixes math_ops.bas. Also: tests/run_compiler_tests.sh now runs the compiled binary from the project root rather than the tempdir where it was built, so test programs that reference tests/programs/ via relative paths (chain_test, common_test, run_file, misc_stmts) resolve their targets. Earlier I'd misdiagnosed those failures as ON ERROR divergence — they were just CWD-dependent path lookups. Doc/test counts: 56 → 63 in README, docs/index.md, docs/development.md, docs/roadmap.md. Roadmap updated to note the compiler now accepts unnumbered programs.
47 lines
2.1 KiB
Markdown
47 lines
2.1 KiB
Markdown
# GW-BASIC 2026
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A portable C reimplementation of Microsoft GW-BASIC, using the
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[original 8088 assembly source](https://github.com/microsoft/GW-BASIC)
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(released by Microsoft in 2020) as the authoritative reference.
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This is not a transpilation -- it reimplements the algorithms in clean C11
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with modern data structures while targeting bug-compatible behavior.
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Unlike the original assembly (43,771 lines across 43 `.ASM` files), this
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version is structured as modular C suitable for new feature development.
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## Highlights
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- **Authentic full-screen editor** -- dynamically sized screen buffer (25×80
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default, full terminal with `--full`), free cursor movement, Enter-on-any-line,
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F1-F10 function keys, Insert/Overwrite toggle
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- **Binary and ASCII file formats** -- `SAVE` writes tokenized binary by default,
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`LOAD` auto-detects format (just like the real thing)
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- **INKEY$ extended keys** -- arrow keys, F-keys, and navigation keys return proper
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`CHR$(0)` + scan code two-byte sequences
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- **Sixel graphics** -- `SCREEN 1`/`SCREEN 2` rendering in compatible terminals
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- **Sound** -- `SOUND`, `BEEP`, `PLAY` (MML) via PulseAudio, plus continuous tone
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via `OUT` (8253 PIT / PPI speaker emulation)
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- **Hardware I/O** -- `OUT`, `INP`, `WAIT` port emulation (PIT, PPI, CGA, COM1,
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game port) for classic programs that drive hardware directly
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- **Full file I/O** -- sequential, random-access, SAVE/LOAD/MERGE/CHAIN/COMMON
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- **Printer output** -- `LPRINT`/`LLIST` to file or real hardware via `--lpt`
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- **Classic programs** -- Hamurabi, Lunar Lander, Gunner, and Diamond from
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David Ahl's *BASIC Computer Games* (1978) run out of the box
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- **Ahead-of-time compiler** -- `gwbasic-compile prog.bas -c` produces native
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executables via C codegen + GCC (63/63 eligible tests pass, 100%)
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- **Jupyter kernel** -- inline Sixel graphics, INPUT support, Pygments syntax
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highlighting; `pip install -e . && gwbasickernel-install --user`
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- **72 test programs** with golden-file regression testing and DOSBox-X
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compatibility testing against real GWBASIC.EXE
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- **MIT License**
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```{toctree}
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:maxdepth: 2
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getting-started
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language-reference
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architecture
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development
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roadmap
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```
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