Please continue the work to get an example Occam program that uses the "course" module to compile and run successfully.
I'll start by understanding the current state of things - what example programs exist and what happens when we try to compile and run one.
{
"prompt": "Find any example occam programs that use the \"course\" module in this project. Look in examples/, tests/, kroc/ directories and anywhere else relevant. Also look at TODO.md to understand what's planned. Report back:\n1. What example programs exist that use the course module\n2. What the TODO.md says about next steps\n3. The contents of any course-related example files\n4. What the course module provides (look at kroc/modules/course/libsrc/ to understand what procs/funcs are exported)",
"subagent_type": "Explore"
}./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/course_out.go kroc/modules/course/libsrc/course.module 2>&1 | tail -20
[
{
"type": "text",
"text": "Perfect! Now I have all the information I need. Let me compile a comprehensive report.\n\n## Report: Course Module in occam2go\n\nBased on my comprehensive search through the occam2go project, here's what I found:\n\n### 1. Example Programs Using the Course Module\n\nThe project contains **extensive examples and exercises** using the course module:\n\n**Examples directory** (`/kroc/modules/course/examples/`):\n- `hello_world.occ` - Simple hello world using `out.string()`\n- `test_utils.occ` - Comprehensive test of utilities: screen control, string I/O, integer output\n- `test_bell.occ` - Testing bell/beep functionality\n- `commstime.occ` - Classic concurrency benchmark\n- `casting.occ`, `cast.occ` - Type conversion examples\n- `echoing.occ`, `double_echo.occ` - Channel echo demonstrations\n- `bar.occ` - Bar chart/display example\n- `sort_pump.occ`, `sort_pump_2.occ`, `sort_inside.occ`, `sort_inside_2.occ` - Sorting algorithm examples\n- `demo.occ` - General demonstration\n\n**Exercises directory** (`/kroc/modules/course/exercises/`): 14 files including q1-7, cylons, bugs, robots, e1\n**Answers directory** (`/kroc/modules/course/answers/`): 11 solution files (q1-7 with variations)\n\nThese are **real-world occam programs** designed for teaching and learning concurrent programming with CSP-based patterns.\n\n### 2. What TODO.md Says About Next Steps\n\nThe TODO.md file identifies the following **blockers for full course module support**:\n\n**Required for shared_screen module** (which extends course module):\n- **`DATA TYPE X IS TYPE:`** — Simple type alias (used in shared_screen.inc)\n- **`DATA TYPE X RECORD`** — Alternative record syntax (vs current `RECORD X`)\n- **Counted array protocol** — `BYTE::[]BYTE` length-prefixed arrays in protocols (used in shared_screen.occ)\n- **`RESULT` param qualifier** — `RESULT INT len` on PROC params for output-only parameters (used in float_io.occ)\n\n**Other language features** (not specific to course module):\n- PRI ALT / PRI PAR (priority variants)\n- PLACED PAR (hardware process assignment)\n- PORT OF (hardware port mapping)\n- `VAL []BYTE` abbreviations (named string constants)\n- `#PRAGMA DEFINED` (compiler hints)\n\n**Current status**: As noted in CLAUDE.md, the full course module (including float_io.occ) **now transpiles successfully** and passes `go vet`. This was completed in Phase 2.\n\n### 3. Course Module Example Files\n\nThe course module consists of **7 main source files** (defined in SConscript):\n\n**`consts.inc`** — ASCII constants and special values:\n```occam\nVAL BYTE NULL IS 0:\nVAL BYTE BELL IS 7:\nVAL BYTE ESCAPE IS 27:\nVAL BYTE DELETE IS 127:\nVAL BYTE FLUSH IS 255:\nVAL INT string.less IS -1:\nVAL INT string.same IS 0:\nVAL INT string.more IS 1:\n```\n\n**`utils.occ`** (1132 lines) — Core I/O and screen utilities:\n- Output: `out.repeat`, `out.ch`, `out.string`, `out.byte`, `out.int`, `out.hex`, `out.bool`, `out.yes.no`, `flush`\n- Input: `in.skip`, `in.digit`, `in.string`, `in.bool`, `in.byte`, `in.int`, `black.hole`\n- Interactive prompts: `ask.string`, `ask.bool`, `ask.byte`, `ask.int`\n- Screen control (VT220 protocol): `cursor.x.y`, `cursor.up/down/left/right`, `erase.eol/bol/line/eos/bos/screen`, `cursor.visible/invisible`\n- Positioning: `pos.int`, `pos.yes.no`\n\n**`string.occ`** — String manipulation functions:\n- `make.string`, `copy.string`, `compare.string`, `find`, `extract`, `append.string`, `uppercase`, `lowercase`\n\n**`demo_cycles.occ`** — Basic concurrency patterns (\"lego land\" catalogue):\n- `id` — Pass-through process\n- `succ` — Increment stream\n- `plus` — Add two streams\n- `delta` — Duplicate stream\n- `prefix` — Output constant then pass-through\n- `tail` — Skip first input then pass-through\n\n**`demo_nets.occ`** — Network combinations of demo cycles:\n- `numbers` — Generate integer sequence (0, 1, 2, ...)\n- `integrate` — Accumulate stream values\n- `pairs` — Adjacent pair sum (A+B, B+C, ...)\n\n**`file_in.occ`** — Non-interactive file input (no echo):\n- `file.in.string` — Read string from file\n- `file.in.int` — Read integer from file\n- Other file-based input variants\n\n**`float_io.occ`** (93KB) — Floating-point formatting:\n- `REAL32TOSTRING` / `REAL64TOSTRING` — Convert floats to formatted strings\n - Free format (automatic)\n - Exponential format (scientific notation)\n - Fixed-point format\n - Handles special values: infinity, NaN\n- Complex algorithm: 1000+ lines of sophisticated arithmetic\n\n**`random.occ`** — Pseudorandom number generation:\n- `random()` — Park & Miller minimal standard PRNG (32-bit)\n- Returns: (random_number, new_seed) as multi-result FUNCTION\n- Period: 2^31 - 1 (full period PRNG)\n- Conditional: 32-bit platform uses full PRNG; 16-bit uses LFSR\n\n### 4. Course Module Exports & Capabilities\n\nThe course module provides **three main capability areas**:\n\n**I/O System**:\n- Formatted output for all types (INT, BYTE, BOOL, strings) with field widths\n- Hexadecimal and decimal integer output\n- Interactive and non-interactive input\n- Echo handling and field validation\n- Floating-point number formatting (free, fixed, exponential)\n\n**Screen/Terminal Control**:\n- VT220-compatible terminal control sequences\n- Cursor positioning and movement\n- Line/screen erasure\n- Cursor visibility control\n\n**Concurrency Patterns**:\n- Basic process types: identity, successor, add, delta2 (fanout), prefix\n- Network compositions: number generation, stream integration, pair sums\n- Demonstrates CSP-style process networks\n\n**String/Number Handling**:\n- String I/O with null termination\n- String comparison (less/same/more)\n- Type conversions (float to string)\n\n**Random Numbers**:\n- Full-period pseudorandom sequences\n- Seed-based generation for reproducibility\n\n---\n\n### Key Integration Notes\n\n1. **Module Loading**: Programs include with `#INCLUDE \"course.module\"`, which automatically includes all 7 source files with proper include guards and dependency ordering.\n\n2. **Channel-Based I/O**: All I/O is **channel-based**: `CHAN BYTE keyboard?`, `screen!`, `error!` — typical pattern for concurrent occam systems.\n\n3. **Real-World Usage**: The 25+ example and exercise programs demonstrate:\n - Teaching concurrency concepts through CSP patterns\n - Practical I/O and terminal interaction\n - Classic algorithms (sorting, ring networks)\n - Float formatting and number generation\n\n4. **Transpilation Status**: The full course module now transpiles to Go and passes `go vet` validation, making it viable for transpiling real educational occam programs to Go."
},
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"text": "agentId: ade8077 (for resuming to continue this agent's work if needed)\n<usage>total_tokens: 71995\ntool_uses: 31\nduration_ms: 69656</usage>"
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]Good - the course module transpiles and passes go vet. Now I need to try to get an actual example program that uses the course module to compile and run. Let me look at the simplest example - hello_world.occ - and try to transpile it.
Good - the course module transpiles cleanly. Now let me look at the simplest example and try to get it running.
{
"file_path": "/home/david/projects/code-associates/occam2go/kroc/modules/course/examples/hello_world.occ"
} 1→#INCLUDE "course.module"
2→
3→PROC hello.world (CHAN BYTE keyboard?, screen!, error!)
4→ --{{{
5→ out.string ("Hello World*c*n", 0, screen!)
6→ --}}}
7→:
8→{
"file_path": "/home/david/projects/code-associates/occam2go/kroc/modules/course/examples/commstime.occ"
} 1→
2→#INCLUDE "course.module"
3→
4→--{{{ PROC seq.delta (CHAN INT in?, out.0!, out.1!)
5→PROC seq.delta (CHAN INT in?, out.0!, out.1!)
6→ WHILE TRUE
7→ INT n:
8→ SEQ
9→ in ? n
10→ out.0 ! n
11→ out.1 ! n
12→:
13→--}}}
14→
15→--{{{ PROC consume (VAL INT n.loops, CHAN INT in?, CHAN BYTE out!)
16→PROC consume (VAL INT n.loops, CHAN INT in?, CHAN BYTE out!)
17→ TIMER tim:
18→ INT t0, t1:
19→ INT value:
20→ SEQ
21→ --{{{ warm-up loop
22→ VAL INT warm.up IS 16:
23→ SEQ i = 0 FOR warm.up
24→ in ? value
25→ --}}}
26→ WHILE TRUE
27→ SEQ
28→ tim ? t0
29→ --{{{ bench-mark loop
30→ SEQ i = 0 FOR n.loops
31→ in ? value
32→ --}}}
33→ tim ? t1
34→ --{{{ report
35→ VAL INT microsecs IS t1 MINUS t0:
36→ VAL INT64 nanosecs IS 1000 * (INT64 microsecs):
37→ SEQ
38→ out.string ("Last value received = ", 0, out!)
39→ out.int (value, 0, out!)
40→ out.string ("*c*n", 0, out!)
41→ out.string ("Time = ", 0, out!)
42→ out.int (microsecs, 0, out!)
43→ out.string (" microsecs*c*n", 0, out!)
44→ out.string ("Time per loop = ", 0, out!)
45→ out.int (INT (nanosecs/(INT64 n.loops)), 0, out!)
46→ out.string (" nanosecs*c*n", 0, out!)
47→ out.string ("Context switch = ", 0, out!)
48→ out.int (INT ((nanosecs/(INT64 n.loops))/4), 0, out!)
49→ out.string (" nanosecs*c*n*n", 0, out!)
50→ --}}}
51→:
52→--}}}
53→
54→--{{{ PROC comms.time (CHAN BYTE keyboard?, screen!, error!)
55→PROC comms.time (CHAN BYTE keyboard?, screen!, error!)
56→
57→ BOOL use.seq.delta:
58→
59→ SEQ
60→
61→ --{{{ announce
62→ SEQ
63→ out.string ("*c*nCommstime in occam ...*c*n*n", 0, screen!)
64→ out.string ("Using the SEQ-output version of the delta process*c*n", 0, screen!)
65→ out.string ("yields a more accurate measure of context-switch time*c*n*n", 0, screen!)
66→ out.string ("Using the PAR-output version carries an extra overhead*c*n", 0, screen!)
67→ out.string ("of one process startup/shutdown per Commstime loop*c*n*n", 0, screen!)
68→ out.string ("By comparing **loop** times between the SEQ and PAR versions,*c*n", 0, screen!)
69→ out.string ("the process startup/shutdown overhead may be deduced*c*n*n", 0, screen!)
70→ --}}}
71→
72→ ask.bool ("Sequential delta? ", use.seq.delta, keyboard?, screen!)
73→ out.string ("*nCommstime starting ...*c*n*n", 0, screen!)
74→
75→ CHAN INT a, b, c, d:
76→ PAR
77→ prefix (0, b?, a!)
78→ IF
79→ use.seq.delta
80→ seq.delta (a?, c!, d!) -- the one defined above
81→ TRUE
82→ delta (a?, c!, d!) -- the one that does a parallel output
83→ succ (c?, b!)
84→ consume (1000000, d?, screen!)
85→
86→:
87→--}}}
88→
89→{
"file_path": "/home/david/projects/code-associates/occam2go/kroc/modules/course/examples/test_utils.occ"
} 1→#INCLUDE "course.module"
2→
3→PROC test (CHAN BYTE keyboard?, screen!, error!)
4→ --{{{
5→ -- COPYRIGHT : P.H.Welch, 1984
6→
7→ SEQ
8→ --{{{ simple pause
9→ SEQ
10→ out.string ("Press a key ...", 0, screen!)
11→ flush (screen!)
12→ --{{{ wait for keystroke
13→ BYTE ch:
14→ keyboard ? ch
15→ --}}}
16→ out.string ("*c*n", 0, screen!)
17→ --}}}
18→ --{{{ test screen
19→ VAL [][2]BYTE coord IS [[41, 11], [20, 5], [30, 15], [3, 16], [12, 20],
20→ [58, 7], [6, 9], [54, 18], [45, 1], [5, 3]]:
21→ VAL INT X IS 0:
22→ VAL INT Y IS 1:
23→ SEQ
24→ erase.screen (screen!)
25→ SEQ i = 0 FOR SIZE coord
26→ VAL [2]BYTE c IS coord[i]:
27→ SEQ
28→ cursor.x.y (c[X], c[Y], screen!)
29→ out.string ("Hello World", 0, screen!)
30→ flush (screen!)
31→ --{{{ wait for keystroke
32→ BYTE ch:
33→ keyboard ? ch
34→ --}}}
35→ erase.screen (screen!)
36→ flush (screen!)
37→ --{{{ wait for keystroke
38→ BYTE ch:
39→ keyboard ? ch
40→ --}}}
41→ SEQ count = 0 FOR 10
42→ VAL BYTE bcount IS BYTE count: -- bcount is a BYTE version of count
43→ SEQ i = 0 FOR SIZE coord -- bcount is needed 3 lines below this one
44→ VAL [2]BYTE c IS coord[i]: -- (because we can't add a BYTE to an INT)
45→ SEQ
46→ cursor.x.y (c[X] + bcount, c[Y] + bcount, screen!)
47→ out.string ("Goodbye World", 0, screen!)
48→ flush (screen!)
49→ --{{{ wait for keystroke
50→ BYTE ch:
51→ keyboard ? ch
52→ --}}}
53→ erase.screen (screen!)
54→ cursor.x.y (1, 1, screen!) -- place cursor top-right on a blank screen
55→ flush (screen!)
56→ --}}}
57→ --{{{ test out.int
58→ SEQ
59→ out.string ("*c*n", 0, screen!)
60→ out.int (42, 10, screen!)
61→ out.int (-42, 10, screen!)
62→ out.string ("*c*n*n", 0, screen!)
63→ --}}}
64→ --{{{ test in.string
65→ [20]BYTE s:
66→ INT length:
67→ BOOL ok:
68→ SEQ
69→ ok := TRUE
70→ WHILE ok
71→ SEQ
72→ out.string ("String (up to 10 characters)? ", 0, screen!)
73→ flush (screen!)
74→ in.string (s, length, 10, keyboard?, screen!)
75→ out.string ("*c*n --> *"", 0, screen!)
76→ out.string ([s FOR length], 0, screen!)
77→ out.string ("*" (", 0, screen!)
78→ out.int (length, 0, screen!)
79→ out.string (" characters)*c*nAgain (yes/no)? ", 0, screen!)
80→ flush (screen!)
81→ in.bool (ok, keyboard?, screen!)
82→ out.string ("*c*n*n", 0, screen!)
83→ --}}}
84→ --{{{ test in.int
85→ INT n:
86→ BOOL ok:
87→ SEQ
88→ ok := TRUE
89→ WHILE ok
90→ SEQ
91→ out.string ("Number? ", 0, screen!)
92→ flush (screen!)
93→ in.int (n, 10, keyboard?, screen!)
94→ out.string ("*c*n --> ", 0, screen!)
95→ out.int (n, 0, screen!)
96→ out.string ("*c*nAgain (yes/no)? ", 0, screen!)
97→ flush (screen!)
98→ in.bool (ok, keyboard?, screen!)
99→ out.string ("*c*n*n", 0, screen!)
100→ --}}}
101→ --{{{ test ask stuff
102→ BOOL more:
103→ SEQ
104→ more := TRUE
105→ WHILE more
106→ [10]BYTE name:
107→ INT name.length, age:
108→ VAL INT this.year IS 2000:
109→ VAL INT target.age IS 21:
110→ SEQ
111→ ask.string ("Name? ", name, name.length, 10, keyboard?, screen!)
112→ ask.int ("Age? ", age, 2, keyboard?, screen!)
113→ out.string (" --> ", 0, screen!)
114→ out.string ([name FOR name.length], 0, screen!)
115→ out.string (" will be ", 0, screen!)
116→ out.int (target.age, 0, screen!)
117→ out.string (" in ", 0, screen!)
118→ out.int (this.year + (target.age - age), 0, screen!)
119→ out.string (" approximately*c*n", 0, screen!)
120→ ask.bool ("Again(yes/no)? ", more, keyboard?, screen!)
121→ out.string ("*c*n", 0, screen!)
122→ --}}}
123→ --{{{ test string stuff
124→ BOOL more:
125→ SEQ
126→ more := TRUE
127→ WHILE more
128→ [10]BYTE a, b:
129→ INT a.length, b.length:
130→ SEQ
131→ ask.string ("First string? ", a, a.length, 10, keyboard?, screen!)
132→ ask.string ("Second string? ", b, b.length, 10, keyboard?, screen!)
133→ IF
134→ equal.string (a, b)
135→ out.string (" --> Strings are the same*c*n", 0, screen!)
136→ TRUE
137→ out.string (" --> Strings are different*c*n", 0, screen!)
138→ CASE compare.string (a, b)
139→ string.less
140→ out.string (" --> First < Second*c*n", 0, screen!)
141→ string.same
142→ out.string (" --> First = Second*c*n", 0, screen!)
143→ string.more
144→ out.string (" --> First > Second*c*n", 0, screen!)
145→ ask.bool ("Again(yes/no)? ", more, keyboard?, screen!)
146→ out.string ("*c*n", 0, screen!)
147→ --}}}
148→ --}}}
149→:
150→Let me start with the simplest example - hello_world.occ. But first I need to understand the structure. The course module defines PROCs that take CHAN BYTE keyboard?, screen!, error! parameters. The main program is also a PROC with that signature. In occam/KRoC, there's a runtime that connects these to stdin/stdout/stderr.
For Go, we need to generate a main() function that:
1. Creates keyboard, screen, and error channels
2. Starts goroutines to read from stdin and write to stdout/stderr
3. Calls the main proc
Let me try transpiling hello_world.occ first to see what happens.
./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/hello_world.go kroc/modules/course/examples/hello_world.occ 2>&1
./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/hello_world.go kroc/modules/course/examples/hello_world.occ 2>&1
Exit code 1 # command-line-arguments runtime.main_main·f: function main is undeclared in the main package # command-line-arguments runtime.main_main·f: function main is undeclared in the main package
As expected - the transpiled code doesn't have a main() function. Let me look at what the transpiled output looks like, and also understand the pattern for how occam programs work. In occam, the entry point is the last PROC that takes (CHAN BYTE keyboard?, screen!, error!) parameters. We need to generate a main() function that:
Let me look at the current transpiled output and also the codegen to understand how to add this.
1→package main
2→
3→import (
4→ "fmt"
5→ "math"
6→ "math/bits"
7→ "os"
8→ "sync"
9→ "time"
10→)
11→
12→// Transputer intrinsic helper functions
13→func _LONGPROD(a, b, c int) (int, int) {
14→ r := uint64(uint32(a))*uint64(uint32(b)) + uint64(uint32(c))
15→ return int(int32(uint32(r >> 32))), int(int32(uint32(r)))
16→}
17→
18→func _LONGDIV(hi, lo, divisor int) (int, int) {
19→ n := (uint64(uint32(hi)) << 32) | uint64(uint32(lo))
20→ d := uint64(uint32(divisor))
21→ if d == 0 { panic("LONGDIV: division by zero") }
22→ return int(int32(uint32(n / d))), int(int32(uint32(n % d)))
23→}
24→
25→func _LONGSUM(a, b, carry int) (int, int) {
26→ r := uint64(uint32(a)) + uint64(uint32(b)) + uint64(uint32(carry))
27→ return int(int32(uint32(r >> 32))), int(int32(uint32(r)))
28→}
29→
30→func _LONGDIFF(a, b, borrow int) (int, int) {
31→ r := uint64(uint32(a)) - uint64(uint32(b)) - uint64(uint32(borrow))
32→ if uint32(a) >= uint32(b)+uint32(borrow) { return 0, int(int32(uint32(r))) }
33→ return 1, int(int32(uint32(r)))
34→}
35→
36→func _NORMALISE(hi, lo int) (int, int, int) {
37→ v := (uint64(uint32(hi)) << 32) | uint64(uint32(lo))
38→ if v == 0 { return 64, 0, 0 }
39→ n := bits.LeadingZeros64(v)
40→ v <<= uint(n)
41→ return n, int(int32(uint32(v >> 32))), int(int32(uint32(v)))
42→}
43→
44→func _SHIFTRIGHT(hi, lo, n int) (int, int) {
45→ v := (uint64(uint32(hi)) << 32) | uint64(uint32(lo))
46→ v >>= uint(uint32(n))
47→ return int(int32(uint32(v >> 32))), int(int32(uint32(v)))
48→}
49→
50→func _SHIFTLEFT(hi, lo, n int) (int, int) { 2650→ _ = new_seed
2651→ magic := 16807
2652→ _ = magic
2653→ period := 2147483647
2654→ _ = period
2655→ quotient := (period / magic)
2656→ _ = quotient
2657→ remainder := (period % magic)
2658→ _ = remainder
2659→ var lo, hi, test int
2660→ _ = lo
2661→ _ = hi
2662→ _ = test
2663→ hi = (seed / quotient)
2664→ lo = (seed % quotient)
2665→ test = ((magic * lo) - (remainder * hi))
2666→ if (test > 0) {
2667→ new_seed = test
2668→ } else if true {
2669→ new_seed = (test + period)
2670→ }
2671→ int_result = (new_seed % upto)
2672→ return int_result, new_seed
2673→}
2674→
2675→func hello_world(keyboard <-chan byte, screen chan<- byte, _error chan<- byte) {
2676→ out_string([]byte("Hello World*c*n"), 0, screen)
2677→}
2678→
2679→Now I can see the issue clearly. The transpiled code:
package main hello_world as the last functionmain() functionI need to understand several things:
*c*n escape isn't being converted to \r\n - that's a bug in string literal handlingmain() function that wires up keyboard/screen/error channels to stdin/stdout/stderrLet me plan this out:
String escape sequences: *c → \r, *n → \n, etc. in string literals. Let me check if this is already handled somewhere.
Main function generation: I need to detect the entry point PROC (the last one with the CHAN BYTE keyboard?, screen!, error! signature) and generate a main() function that creates the three channels, spins up goroutines to bridge them to stdin/stdout/stderr, calls the entry PROC, and handles cleanup.
Now I'm noticing that string escape sequences aren't being converted properly—looking at the output, *c*n should become \r\n in Go string literals, but it's staying as-is. Let me trace through how the lexer and code generator handle string literals to find where this conversion should happen.
I can see two problems:
1. No main() function is generated
2. Occam escape sequences (*c*n) aren't being converted to Go escapes (\r\n)
Let me enter plan mode to design the implementation properly.
Entered plan mode. You should now focus on exploring the codebase and designing an implementation approach. In plan mode, you should: 1. Thoroughly explore the codebase to understand existing patterns 2. Identify similar features and architectural approaches 3. Consider multiple approaches and their trade-offs 4. Use AskUserQuestion if you need to clarify the approach 5. Design a concrete implementation strategy 6. When ready, use ExitPlanMode to present your plan for approval Remember: DO NOT write or edit any files yet. This is a read-only exploration and planning phase.
{
"prompt": "In the occam2go project at /home/david/projects/code-associates/occam2go, I need to understand how occam string escape sequences are currently handled. Occam uses `*c` for carriage return, `*n` for newline, `*t` for tab, `*s` for space, `**` for literal asterisk, `*\"` for literal double quote, and `*'` for literal single quote.\n\nSearch for:\n1. How string literals are tokenized in lexer/lexer.go - look for string scanning code\n2. How string literals are generated in codegen/codegen.go - look for string generation code\n3. How byte literals (e.g., '*n') are handled in lexer and codegen\n4. Any existing conversion of occam escape sequences to Go escape sequences\n5. What the AST nodes for string/byte literals look like in ast/ast.go\n\nReport the relevant code sections with line numbers.",
"subagent_type": "Explore"
}{
"prompt": "In the occam2go project at /home/david/projects/code-associates/occam2go, I need to understand:\n\n1. How the codegen currently generates the top-level output. Look at codegen/codegen.go for the Generate() function or similar entry point. How does it decide what package to use, what imports to add, etc?\n\n2. How PROCs with the signature `CHAN BYTE keyboard?, screen!, error!` are detected and handled. This is the standard occam entry point signature.\n\n3. Look at main.go to understand the CLI flow and how files are processed (especially the distinction between .occ files and .module files)\n\n4. Look at how proc signatures are collected and stored (procSigs). What information is available about proc parameters?\n\n5. Check if there's any existing mechanism to detect whether we're compiling a standalone program vs. a library/module.\n\n6. Look at how the existing e2e tests in codegen/e2e_test.go generate and run programs - they must have some way of creating runnable Go programs with main functions.\n\nReport all relevant code sections with file paths and line numbers.",
"subagent_type": "Explore"
}[
{
"type": "text",
"text": "Perfect! Now I have all the information I need. Let me compile my findings.\n\n## Summary of Occam String Escape Sequence Handling in occam2go\n\nBased on my thorough search of the codebase, here's how string and byte escape sequences are currently handled:\n\n### 1. **String Literal Tokenization (lexer/lexer.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/lexer/lexer.go`, lines 304-312\n\n```go\nfunc (l *Lexer) readString() string {\n\tposition := l.position + 1\n\tfor {\n\t\tl.readChar()\n\t\tif l.ch == '\"' || l.ch == 0 {\n\t\t\tbreak\n\t\t}\n\t}\n\treturn l.input[position:l.position]\n}\n```\n\n**Key Finding:** String literals are read **as-is** between double quotes. The lexer does **NOT** process occam escape sequences in strings. It simply extracts the raw text between `\"` characters and returns it unchanged. This means escape sequences like `*n`, `*t`, `*c` etc. would be stored literally in the Token.Literal field.\n\n---\n\n### 2. **Byte Literal Tokenization (lexer/lexer.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/lexer/lexer.go`, lines 315-340\n\n```go\nfunc (l *Lexer) readByteLiteral() string {\n\t// Current char is the opening single quote.\n\t// Read content between single quotes, handling *' escape.\n\t// In occam, * is the escape character. ** means literal *, *' means literal '.\n\tposition := l.position + 1\n\tescaped := false\n\tfor {\n\t\tl.readChar()\n\t\tif l.ch == 0 {\n\t\t\tbreak\n\t\t}\n\t\tif escaped {\n\t\t\t// This char is the escaped character; consume it and clear flag\n\t\t\tescaped = false\n\t\t\tcontinue\n\t\t}\n\t\tif l.ch == '*' {\n\t\t\tescaped = true\n\t\t\tcontinue\n\t\t}\n\t\tif l.ch == '\\'' {\n\t\t\tbreak\n\t\t}\n\t}\n\treturn l.input[position:l.position]\n}\n```\n\n**Key Finding:** Byte literals are read with escape sequence awareness. The lexer tracks the escape character (`*`) but returns the **raw content** including the escape sequences. The actual parsing happens later in the parser.\n\n---\n\n### 3. **Byte Literal Value Parsing (parser/parser.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/parser/parser.go`, lines 2317-2350\n\n```go\nfunc (p *Parser) parseByteLiteralValue(raw string) (byte, error) {\n\tif len(raw) == 0 {\n\t\treturn 0, fmt.Errorf(\"empty byte literal\")\n\t}\n\tif raw[0] == '*' {\n\t\tif len(raw) != 2 {\n\t\t\treturn 0, fmt.Errorf(\"invalid escape sequence in byte literal: '*%s'\", raw[1:])\n\t\t}\n\t\tswitch raw[1] {\n\t\tcase 'n':\n\t\t\treturn '\\n', nil // ASCII 10\n\t\tcase 'c':\n\t\t\treturn '\\r', nil // ASCII 13 (carriage return)\n\t\tcase 't':\n\t\t\treturn '\\t', nil // ASCII 9\n\t\tcase 's':\n\t\t\treturn ' ', nil // ASCII 32 (space)\n\t\tcase '*':\n\t\t\treturn '*', nil // ASCII 42\n\t\tcase '\\'':\n\t\t\treturn '\\'', nil // ASCII 39\n\t\tcase '\"':\n\t\t\treturn '\"', nil // ASCII 34\n\t\tdefault:\n\t\t\treturn 0, fmt.Errorf(\"unknown escape sequence in byte literal: '*%c'\", raw[1])\n\t\t}\n\t}\n\tif len(raw) != 1 {\n\t\treturn 0, fmt.Errorf(\"byte literal must be a single character, got %q\", raw)\n\t}\n\treturn raw[0], nil\n}\n```\n\n**Key Finding:** The parser converts occam escape sequences in byte literals to their Go equivalents:\n- `*n` → newline (10)\n- `*c` → carriage return (13)\n- `*t` → tab (9)\n- `*s` → space (32)\n- `**` → asterisk (42)\n- `*'` → single quote (39)\n- `*\"` → double quote (34)\n\n---\n\n### 4. **AST Nodes (ast/ast.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/ast/ast.go`, lines 260-276\n\n```go\n// StringLiteral represents a string literal: \"hello\"\ntype StringLiteral struct {\n\tToken lexer.Token\n\tValue string // Raw string content as extracted from lexer\n}\n\n// ByteLiteral represents a byte literal: 'A', '*n', etc.\ntype ByteLiteral struct {\n\tToken lexer.Token\n\tValue byte // Processed byte value (escape sequence already converted)\n}\n```\n\n**Key Finding:** \n- `StringLiteral.Value` contains the **raw string** as extracted by the lexer\n- `ByteLiteral.Value` contains the **processed byte value** (integer 0-255)\n\n---\n\n### 5. **Parser Expression Handling (parser/parser.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/parser/parser.go`, lines 2610-2618\n\n```go\ncase lexer.STRING:\n\tleft = &ast.StringLiteral{Token: p.curToken, Value: p.curToken.Literal}\ncase lexer.BYTE_LIT:\n\tb, err := p.parseByteLiteralValue(p.curToken.Literal)\n\tif err != nil {\n\t\tp.addError(err.Error())\n\t\treturn nil\n\t}\n\tleft = &ast.ByteLiteral{Token: p.curToken, Value: b}\n```\n\n**Key Finding:** \n- String literals are stored verbatim\n- Byte literals are processed through `parseByteLiteralValue()` to convert escape sequences\n\n---\n\n### 6. **Code Generation (codegen/codegen.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/codegen/codegen.go`, lines 2059-2062\n\n```go\ncase *ast.StringLiteral:\n\tg.write(fmt.Sprintf(\"%q\", e.Value)) // Uses Go's %q format for quoting\ncase *ast.ByteLiteral:\n\tg.write(fmt.Sprintf(\"byte(%d)\", e.Value)) // Generates byte(N) where N is the numeric value\n```\n\n**Key Finding:** \n- Strings use Go's `%q` format specifier, which handles Go escape sequences\n- **CRITICAL ISSUE:** String literals are output as-is using `%q`. This means occam escape sequences in strings are NOT converted to Go escape sequences\n\n**Example:**\n- Occam: `x := \"hello*nworld\"` \n- Current output: `x = \"hello*nworld\"` (incorrect - Go won't recognize `*n` as newline)\n- Should be: `x = \"hello\\nworld\"` (correct - Go interprets `\\n` as newline)\n\n---\n\n### 7. **Special Handling: Strings as []BYTE Parameters (codegen/codegen.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/codegen/codegen.go`, lines 1687-1693\n\n```go\n// Wrap string literals with []byte() when passed to []BYTE parameters\nif _, isStr := arg.(*ast.StringLiteral); isStr && i < len(params) && params[i].IsOpenArray && params[i].Type == \"BYTE\" {\n\tg.write(\"[]byte(\")\n\tg.generateExpression(arg)\n\tg.write(\")\")\n} else {\n\tg.generateExpression(arg)\n}\n```\n\n**Key Finding:** String literals passed to `[]BYTE` parameters are wrapped in `[]byte()` for type conversion.\n\n---\n\n### 8. **Byte Literal Tests (parser/parser_test.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/parser/parser_test.go`, lines 1344-1385\n\nTest coverage for byte literal escape sequences:\n```go\n{\"x := '*n'\\n\", '\\n'},\n{\"x := '*c'\\n\", '\\r'},\n{\"x := '*t'\\n\", '\\t'},\n{\"x := '*s'\\n\", ' '},\n{\"x := '**'\\n\", '*'},\n{\"x := '*''\\n\", '\\''},\n{\"x := '*\\\"'\\n\", '\"'},\n```\n\n---\n\n### 9. **Codegen Test for Byte Literals (codegen/codegen_test.go)**\n\n**Location:** `/home/david/projects/code-associates/occam2go/codegen/codegen_test.go`, lines 262-268\n\n```go\nfunc TestByteLiteralEscape(t *testing.T) {\n\tinput := \"x := '*n'\\n\"\n\toutput := transpile(t, input)\n\n\tif !strings.Contains(output, \"x = byte(10)\") {\n\t\tt.Errorf(\"expected 'x = byte(10)' in output, got:\\n%s\", output)\n\t}\n}\n```\n\n**Key Finding:** Byte literal `*n` correctly generates `byte(10)` in Go output.\n\n---\n\n## Key Issues Identified\n\n1. **STRING ESCAPE SEQUENCES NOT CONVERTED**: String literals with occam escape sequences (`*n`, `*t`, `*c`, `*s`, `**`, `*\"`, `*'`) are NOT converted to Go escape sequences (`\\n`, `\\t`, `\\r`, ` `, `*`, `\"`, `'`). This is a bug - strings like `\"hello*nworld\"` would output literally instead of with a newline.\n\n2. **BYTE LITERALS WORK CORRECTLY**: Byte literals properly convert occam escape sequences to their numeric byte values.\n\n3. **MISSING STRING ESCAPE PROCESSING**: There is no function equivalent to `parseByteLiteralValue()` for string literals. The lexer just returns the raw content.\n\nThe code for string escape conversion would need to be added to properly handle occam escape sequences in string literals before Go code generation."
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][
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"type": "text",
"text": "Perfect! I now have a comprehensive understanding of the codebase. Let me compile my findings into a detailed report.\n\n## Summary of Findings: occam2go Code Architecture and Key Mechanisms\n\nI've thoroughly analyzed the occam2go project and identified the key areas you requested. Here's a comprehensive report:\n\n---\n\n### 1. **Top-Level Code Generation (codegen/codegen.go: Generate function)**\n\n**File:** `/home/david/projects/code-associates/occam2go/codegen/codegen.go`\n**Lines:** 88-271\n\nThe `Generate()` function handles:\n\n- **Package declaration** (line 146): Always hardcoded as `package main`\n- **Import management** (lines 150-174): Conditionally imports `fmt`, `math`, `math/bits`, `os`, `sync`, `time` based on content analysis\n- **Two-pass approach**:\n - **First pass** (lines 105-143): Scans AST to collect procedure signatures, protocols, records, and track which imports are needed\n - **Second pass** (lines 181-268): Separates statements into categories and generates code\n\n**Key Logic (lines 186-268):**\n```\n1. Check for any ProcDecl/FuncDecl (hasProcDecls flag)\n2. Separate statements into categories:\n - typeDecls: PROTOCOL, RECORD declarations\n - procDecls: PROC, FUNCTION declarations\n - abbrDecls: Top-level VAL abbreviations (only if hasProcDecls)\n - mainStatements: Everything else\n3. Generate in order: type decls → abbreviations → procedures → main()\n4. Only generate func main() if len(mainStatements) > 0\n```\n\n---\n\n### 2. **Standard Entry Point Detection (CHAN BYTE keyboard, screen, error)**\n\n**Current Status:** No existing detection mechanism\n\nThe codebase currently has **no special handling** for the standard occam entry point signature `PROC name(CHAN BYTE keyboard?, screen!, error!)`. This is what needs to be implemented.\n\n**Where detection would go:** In `codegen/codegen.go`, either in the `Generate()` function or in a new helper function.\n\n**ProcParam structure** (ast/ast.go, lines 143-154):\n```go\ntype ProcParam struct {\n IsVal bool\n Type string // \"INT\", \"BYTE\", \"BOOL\", etc.\n Name string\n IsChan bool\n IsChanArray bool\n IsOpenArray bool\n ChanElemType string // e.g., \"BYTE\"\n ChanDir string // \"?\" for input, \"!\" for output, \"\" for bidirectional\n ArraySize string\n}\n```\n\nTo detect the standard entry point, you'd check:\n- Exactly 3 parameters\n- All are `IsChan == true` with `ChanElemType == \"BYTE\"`\n- Parameter 1: `ChanDir == \"?\"` (keyboard input)\n- Parameter 2: `ChanDir == \"!\"` (screen output)\n- Parameter 3: `ChanDir == \"!\"` (error output)\n\n---\n\n### 3. **CLI Flow and File Processing (main.go)**\n\n**File:** `/home/david/projects/code-associates/occam2go/main.go`\n\n**Flow (lines 27-119):**\n```\n1. Check for \"gen-module\" subcommand (lines 29-32)\n2. Parse flags: -o (output), -I (include paths), -D (defines) (lines 34-39)\n3. Preprocess file (lines 75-89):\n - preproc.New() with include paths and defines\n - pp.ProcessFile(inputFile) → expanded text\n4. Lex (line 92): lexer.New(expanded)\n5. Parse (lines 95-104): parser.New(l) → AST\n6. Generate (lines 107-108): gen.Generate(program)\n7. Write output (lines 111-119)\n```\n\n**File Type Handling:**\n- Both `.occ` and `.module` files are processed identically through the same pipeline\n- The distinction happens in the **preprocessor** (`preproc/preproc.go`), which resolves `#INCLUDE` directives\n- `.module` files are just `.occ` files with mostly `#INCLUDE` statements wrapped in header guards\n\n**Key insight:** There's no CLI distinction between standalone programs and libraries. The transpiler always generates `package main` with a `func main()` if there are non-procedure statements.\n\n---\n\n### 4. **Procedure Signature Collection and Storage (procSigs)**\n\n**File:** `/home/david/projects/code-associates/occam2go/codegen/codegen.go`\n\n**Location and initialization:**\n- Lines 22: `procSigs map[string][]ast.ProcParam` in Generator struct\n- Line 96: Initialized as `g.procSigs = make(map[string][]ast.ProcParam)`\n\n**Collection process:**\n\na) **Global procedures** (lines 128-134, first pass of Generate):\n```go\nif proc, ok := stmt.(*ast.ProcDecl); ok {\n g.procSigs[proc.Name] = proc.Params\n g.collectNestedProcSigs(proc.Body)\n}\n```\n\nb) **Nested procedures** (lines 273-300, collectNestedProcSigs):\n```go\ncase *ast.ProcDecl:\n g.procSigs[s.Name] = s.Params\n g.collectNestedProcSigs(s.Body) // Recursive\n```\n\nc) **Scoped nested procedures** (lines 306-337, collectNestedProcSigsScoped):\n- Used when entering a proc scope to prevent name collisions\n- Saves old signatures and restores them when exiting scope\n- Critical for handling same-named nested procs in different parent procs\n\n**Usage:**\n- Line 1675: Looked up in `generateProcCall()` to determine reference vs. value semantics\n- Lines 1683-1685: Determines if address-of operator (`&`) is needed when passing arguments\n\n---\n\n### 5. **Standalone vs. Library Detection**\n\n**Current Status:** Not implemented\n\n**How to detect:**\n\nThe project currently has **no mechanism** to distinguish between a standalone program and a library module. Currently:\n\n- All transpiled code gets `package main`\n- All code with non-procedure statements gets `func main()`\n- There's no `package library` or \"no main\" mode\n\n**Possible detection strategies:**\n\n1. **Command-line flag**: Add `-library` or `--module` flag to main.go\n2. **File extension**: `.module` files could be treated differently than `.occ` files\n3. **Content-based**: Check if all statements are PROC/FUNC declarations (no other statements) → library\n4. **Entry point detection**: If top-level PROC with name matching standard entry pattern (e.g., `comms.time`, `run`, `main`), treat as executable\n\n**Currently, the only hint is in modgen.go** (lines 26-45), which generates `.module` files, but that's a separate preprocessing step, not integrated into the transpiler's generation logic.\n\n---\n\n### 6. **E2E Test Infrastructure (codegen/e2e_helpers_test.go)**\n\n**Files:**\n- `/home/david/projects/code-associates/occam2go/codegen/e2e_helpers_test.go` (helpers)\n- `/home/david/projects/code-associates/occam2go/codegen/codegen_test.go` (unit tests)\n- `/home/david/projects/code-associates/occam2go/codegen/e2e_basic_test.go` (e2e tests)\n\n**Main function: transpileCompileRun** (lines 16-62):\n```go\nfunc transpileCompileRun(t *testing.T, occamSource string) string {\n // 1. Transpile: lexer → parser → codegen\n // 2. Write to temp file\n // 3. Compile with: go build -o binFile goFile\n // 4. Run: exec.Command(binFile)\n // 5. Return stdout\n}\n```\n\n**How it creates runnable programs:**\n1. Takes Occam source string\n2. Transpiles via `gen.Generate(program)` → Go code with `func main()`\n3. Writes to temp file: `filepath.Join(tmpDir, \"main.go\")`\n4. Compiles: `go build -o main main.go`\n5. Executes and captures output\n6. Cleanup: `defer os.RemoveAll(tmpDir)`\n\n**Two variants:**\n- `transpileCompileRun()`: Takes Occam source string directly\n- `transpileCompileRunFromFile()`: Preprocesses a file first with include paths\n\n**Example test** (e2e_basic_test.go, lines 8-19):\n```go\nfunc TestE2E_PrintInt(t *testing.T) {\n occam := `SEQ\n INT x:\n x := 42\n print.int(x)\n`\n output := transpileCompileRun(t, occam)\n expected := \"42\\n\"\n if output != expected {\n t.Errorf(\"expected %q, got %q\", expected, output)\n }\n}\n```\n\nThis test shows that **the transpiler always generates a complete, runnable program** with a `func main()` when there are non-procedure statements.\n\n---\n\n### 7. **Key Architectural Patterns**\n\n**a) RETYPES Parameter Renaming** (lines 1555-1573):\nWhen a RETYPES declaration shadows a parameter name (e.g., `VAL INT X RETYPES X :`), the parameter is renamed in the signature (e.g., `_rp_X`) because Go doesn't allow `:=` to redeclare a parameter in the same scope.\n\n**b) Reference vs. Value Parameters** (lines 1616-1644):\n- `VAL` parameters → pass by value (no `*`)\n- Non-`VAL` parameters → pointers (with `*`)\n- Channels, arrays → already reference types (no pointer wrapper)\n\n**c) Nesting level tracking** (line 36):\n- `nestingLevel == 0`: Package level (procedures generated as `func NAME(...)`)\n- `nestingLevel > 0`: Inside a function (procedures generated as `name := func(...)` closures)\n\n**d) Channel Direction Prefixes** (lines 1646-1655):\n- `\"?\"` → `<-chan` (input/receive-only)\n- `\"!\"` → `chan<-` (output/send-only)\n- `\"\"` → `chan` (bidirectional)\n\n---\n\n### Summary: Path Forward for Standard Entry Point Handling\n\nTo implement detection and handling of the standard `PROC name(CHAN BYTE keyboard?, screen!, error!)` entry point:\n\n1. **Detection** (in `codegen/codegen.go` Generate function):\n - After collecting proc signatures, check all top-level PROCs\n - Identify any with 3 BYTE channel parameters with the correct directions\n\n2. **Decision point**:\n - Generate wrapper code that accepts these channels and calls the user proc\n - OR generate special main that creates pipe/stream connections to the proc\n - OR just treat as a regular proc and let the caller provide channels\n\n3. **Integration point**:\n - Modify `Generate()` function around lines 256-268 where `func main()` is conditionally generated\n - Could check if a standard entry point exists and handle it specially\n\nAll the infrastructure is already in place—procSigs contains full parameter information, and the generation pipeline can easily be adapted to create wrapper functions or special initialization code."
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]Now I have a clear picture. Let me look at a few more specific things before writing the plan:
Let me read the key parts of the codegen and understand the exact code generation flow.
{
"file_path": "/home/david/projects/code-associates/occam2go/codegen/codegen.go",
"limit": 100,
"offset": 85
} 85→}
86→
87→// Generate produces Go code from the AST
88→func (g *Generator) Generate(program *ast.Program) string {
89→ g.builder.Reset()
90→ g.needSync = false
91→ g.needFmt = false
92→ g.needTime = false
93→ g.needOs = false
94→ g.needMath = false
95→ g.needMathBits = false
96→ g.procSigs = make(map[string][]ast.ProcParam)
97→ g.refParams = make(map[string]bool)
98→ g.protocolDefs = make(map[string]*ast.ProtocolDecl)
99→ g.chanProtocols = make(map[string]string)
100→ g.tmpCounter = 0
101→ g.recordDefs = make(map[string]*ast.RecordDecl)
102→ g.recordVars = make(map[string]string)
103→
104→ // First pass: collect procedure signatures, protocols, and check for PAR/print
105→ for _, stmt := range program.Statements {
106→ if g.containsPar(stmt) {
107→ g.needSync = true
108→ }
109→ if g.containsPrint(stmt) {
110→ g.needFmt = true
111→ }
112→ if g.containsTimer(stmt) {
113→ g.needTime = true
114→ }
115→ if g.containsStop(stmt) {
116→ g.needOs = true
117→ g.needFmt = true
118→ }
119→ if g.containsMostExpr(stmt) {
120→ g.needMath = true
121→ }
122→ if g.containsIntrinsics(stmt) {
123→ g.needMathBits = true
124→ }
125→ if g.containsRetypes(stmt) {
126→ g.needMath = true
127→ }
128→ if proc, ok := stmt.(*ast.ProcDecl); ok {
129→ g.procSigs[proc.Name] = proc.Params
130→ g.collectNestedProcSigs(proc.Body)
131→ }
132→ if fn, ok := stmt.(*ast.FuncDecl); ok {
133→ g.procSigs[fn.Name] = fn.Params
134→ }
135→ if proto, ok := stmt.(*ast.ProtocolDecl); ok {
136→ g.protocolDefs[proto.Name] = proto
137→ }
138→ if rec, ok := stmt.(*ast.RecordDecl); ok {
139→ g.recordDefs[rec.Name] = rec
140→ }
141→ g.collectChanProtocols(stmt)
142→ g.collectRecordVars(stmt)
143→ }
144→
145→ // Write package declaration
146→ g.writeLine("package main")
147→ g.writeLine("")
148→
149→ // Write imports
150→ if g.needSync || g.needFmt || g.needTime || g.needOs || g.needMath || g.needMathBits {
151→ g.writeLine("import (")
152→ g.indent++
153→ if g.needFmt {
154→ g.writeLine(`"fmt"`)
155→ }
156→ if g.needMath {
157→ g.writeLine(`"math"`)
158→ }
159→ if g.needMathBits {
160→ g.writeLine(`"math/bits"`)
161→ }
162→ if g.needOs {
163→ g.writeLine(`"os"`)
164→ }
165→ if g.needSync {
166→ g.writeLine(`"sync"`)
167→ }
168→ if g.needTime {
169→ g.writeLine(`"time"`)
170→ }
171→ g.indent--
172→ g.writeLine(")")
173→ g.writeLine("")
174→ }
175→
176→ // Emit transputer intrinsic helper functions
177→ if g.needMathBits {
178→ g.emitIntrinsicHelpers()
179→ }
180→
181→ // Separate protocol, record, procedure declarations from other statements
182→ var typeDecls []ast.Statement
183→ var procDecls []ast.Statement
184→ var mainStatements []ast.Statement{
"file_path": "/home/david/projects/code-associates/occam2go/codegen/codegen.go",
"limit": 100,
"offset": 185
} 185→
186→ // First pass: check if there are any proc/func declarations
187→ hasProcDecls := false
188→ for _, stmt := range program.Statements {
189→ if _, ok := stmt.(*ast.ProcDecl); ok {
190→ hasProcDecls = true
191→ break
192→ }
193→ if _, ok := stmt.(*ast.FuncDecl); ok {
194→ hasProcDecls = true
195→ break
196→ }
197→ }
198→
199→ var abbrDecls []ast.Statement
200→ for _, stmt := range program.Statements {
201→ switch s := stmt.(type) {
202→ case *ast.ProtocolDecl, *ast.RecordDecl:
203→ typeDecls = append(typeDecls, stmt)
204→ case *ast.ProcDecl, *ast.FuncDecl:
205→ procDecls = append(procDecls, stmt)
206→ case *ast.Abbreviation:
207→ if hasProcDecls {
208→ // Top-level abbreviations need to be at package level
209→ // so PROCs can reference them
210→ abbrDecls = append(abbrDecls, stmt)
211→ } else {
212→ mainStatements = append(mainStatements, stmt)
213→ }
214→ case *ast.RetypesDecl:
215→ _ = s
216→ // RETYPES declarations are local to functions, not package-level
217→ mainStatements = append(mainStatements, stmt)
218→ default:
219→ mainStatements = append(mainStatements, stmt)
220→ }
221→ }
222→
223→ // Generate type definitions first (at package level)
224→ for _, stmt := range typeDecls {
225→ g.generateStatement(stmt)
226→ }
227→
228→ // Generate package-level abbreviations (constants)
229→ for _, stmt := range abbrDecls {
230→ abbr := stmt.(*ast.Abbreviation)
231→ if abbr.Type == "" {
232→ // Untyped VAL: let Go infer the type
233→ g.builder.WriteString("var ")
234→ g.write(fmt.Sprintf("%s = ", goIdent(abbr.Name)))
235→ g.generateExpression(abbr.Value)
236→ g.write("\n")
237→ } else {
238→ goType := g.occamTypeToGo(abbr.Type)
239→ if abbr.IsOpenArray {
240→ goType = "[]" + goType
241→ }
242→ g.builder.WriteString("var ")
243→ g.write(fmt.Sprintf("%s %s = ", goIdent(abbr.Name), goType))
244→ g.generateExpression(abbr.Value)
245→ g.write("\n")
246→ }
247→ }
248→ if len(abbrDecls) > 0 {
249→ g.writeLine("")
250→ }
251→
252→ // Generate procedure declarations (at package level)
253→ for _, stmt := range procDecls {
254→ g.generateStatement(stmt)
255→ }
256→
257→ // Generate main function with other statements
258→ if len(mainStatements) > 0 {
259→ g.writeLine("func main() {")
260→ g.indent++
261→ g.nestingLevel++
262→ for _, stmt := range mainStatements {
263→ g.generateStatement(stmt)
264→ }
265→ g.nestingLevel--
266→ g.indent--
267→ g.writeLine("}")
268→ }
269→
270→ return g.builder.String()
271→}
272→
273→// collectNestedProcSigs recursively collects procedure/function signatures
274→// from nested declarations inside PROC bodies.
275→func (g *Generator) collectNestedProcSigs(stmts []ast.Statement) {
276→ for _, stmt := range stmts {
277→ switch s := stmt.(type) {
278→ case *ast.ProcDecl:
279→ g.procSigs[s.Name] = s.Params
280→ g.collectNestedProcSigs(s.Body)
281→ case *ast.FuncDecl:
282→ g.procSigs[s.Name] = s.Params
283→ g.collectNestedProcSigs(s.Body)
284→ case *ast.SeqBlock:{
"file_path": "/home/david/projects/code-associates/occam2go/codegen/codegen.go",
"limit": 20,
"offset": 2055
} 2055→ g.write(goIdent(e.Value))
2056→ }
2057→ case *ast.IntegerLiteral:
2058→ g.write(fmt.Sprintf("%d", e.Value))
2059→ case *ast.StringLiteral:
2060→ g.write(fmt.Sprintf("%q", e.Value))
2061→ case *ast.ByteLiteral:
2062→ g.write(fmt.Sprintf("byte(%d)", e.Value))
2063→ case *ast.BooleanLiteral:
2064→ if e.Value {
2065→ g.write("true")
2066→ } else {
2067→ g.write("false")
2068→ }
2069→ case *ast.BinaryExpr:
2070→ g.generateBinaryExpr(e)
2071→ case *ast.UnaryExpr:
2072→ g.generateUnaryExpr(e)
2073→ case *ast.SizeExpr:
2074→ g.write("len(")Now I have a clear picture. Let me also look at how the course module expects to be used - specifically the structure of an occam "program" vs a "library":
An occam program (like hello_world.occ) has #INCLUDE "course.module" and then defines a PROC with the standard entry point (CHAN BYTE keyboard?, screen!, error!). The KRoC runtime creates the channels and wires them to stdin/stdout/stderr.
An occam library (like course.module) just defines PROCs and FUNCTIONs.
For the transpiler, when it encounters a program like hello_world.occ:
It includes the course module's utilities, then has the main PROC as the last definition. Since there are currently no main statements being generated, I need to detect that final PROC with the (CHAN BYTE keyboard?, screen!, error!) signature as the entry point and generate a func main() that sets up buffered byte channels for keyboard, screen, and error, then spawns a goroutine to handle stdin reading.
I also need to handle the other goroutines for stdout and stderr output, call the entry PROC with these channels, and manage proper shutdown. Additionally, I should fix occam string escape sequences like *c, *n, *t to their Go equivalents \r, \n, \t.
Looking at the channel semantics, keyboard? is an input channel receiving bytes, while screen! and error! are output channels sending bytes.
Setting up the main function... I'm realizing I need to reconsider the channel directions more carefully—the PROC expects keyboard as a read-only channel, screen and error as write-only channels, so I should be passing them with the appropriate directional types even though Go allows bidirectional channels to be implicitly converted.
For the flush behavior, I'm looking at how the course module implements output—individual bytes flow through the screen channel one at a time, so I need buffering with strategic flushing, likely triggered by a special byte value like 255 (FLUSH) or on newline characters to keep performance reasonable.
I'll need to add bufio to the imports along with os for stdin/stdout/stderr access. When the transpiler converts a PROC like hello_world, it becomes a Go function that takes the three channels and calls helper functions like out_string to write to the screen channel.
The real issue is that occam string escapes like *c and *n aren't being converted to Go escapes like \r and \n. I need to preprocess the string value before passing it to fmt.Sprintf("%q", ...) so that occam escape sequences get translated to their Go equivalents. When %q formats it, it produces "Hello World*c*n" literally. We need to convert *c → \r, *n → \n, etc. first.
The conversion should happen either in the parser when creating StringLiteral nodes—storing the actual bytes—or in the codegen when emitting, converting occam escapes to Go escapes. I think parsing is cleaner since we'd store the semantic value once and %q would handle the rest correctly, plus it's consistent with how byte literals work.
Now I'm thinking about generating main() for entry point PROCs. In the Generate() function, after separating procedure declarations from main statements, I need to check whether there are any main statements at all or if it's just declarations, and identify which procedure should be the entry point.
The entry point detection looks for a PROC with exactly three channel-of-BYTE parameters: input, output, and output respectively. If that matches and there are no other main statements, I'll generate a harness that wires stdin/stdout/stderr to channels and calls it.
I'm wondering if I need a CLI flag for this or if auto-detection is enough. For now auto-detection seems reasonable—if the program only has declarations and one matches the entry pattern, generate the harness. Though I should double-check whether the course module itself has PROCs matching this signature, since that might complicate things.
Looking at the course module, it just defines utility functions like out_string and out_int that don't match the three-channel pattern, so the entry point detection is specific to executable programs. If multiple PROCs match, I should use the last one by convention. For the course module itself, since it has no entry point PROC and no main statements, I shouldn't generate a main function—go build will fail with a missing main error, but that's expected for a library module.
My strategy is to check if mainStatements is empty after separation. If it is, I'll search for the last top-level PROC with the three CHAN BYTE parameters and generate the main harness if found; otherwise, skip it for library modules. When the harness is generated, I'll need to conditionally import bufio, os, and sync for the buffered I/O and goroutine coordination.
For hello_world specifically, the transpiled code will include both the course module functions and hello_world itself, so main() needs to invoke hello_world. Since the out_string function sends bytes individually through a channel, I should implement buffering in the harness and handle the FLUSH byte (255) to flush output to stdout.
For the keyboard channel, I need to ensure the program doesn't block waiting for input when it's not needed, like in the hello_world case. Starting it as a daemon goroutine that exits when main returns is the simplest approach. On channel buffering, I'm reconsidering whether we even need large buffers—a simpler, unbuffered channel design might work fine here.
Actually, thinking through the tradeoffs: unbuffered channels mean every byte send blocks until the receiver is ready, which is correct but potentially slow. Buffered channels let the sender batch writes without blocking, which is more performant. For the initial implementation, I'll go with buffered channels and buffered I/O with FLUSH support, and we can optimize further if needed.
Setting up the main function with three buffered channels for keyboard input, screen output, and error output... Setting up the main harness and handling string escape sequences should get hello_world functional, then I can move on to testing with more complex examples like the INT64 type support later.
Good, I have a clear picture now. Let me also check a few more things about the string escape handling and how it interacts with %q.
{
"file_path": "/home/david/projects/code-associates/occam2go/parser/parser.go",
"limit": 40,
"offset": 2317
} 2317→// parseByteLiteralValue processes the raw content of a byte literal (between single quotes),
2318→// handling occam escape sequences (* prefix), and returns the resulting byte value.
2319→func (p *Parser) parseByteLiteralValue(raw string) (byte, error) {
2320→ if len(raw) == 0 {
2321→ return 0, fmt.Errorf("empty byte literal")
2322→ }
2323→ if raw[0] == '*' {
2324→ if len(raw) != 2 {
2325→ return 0, fmt.Errorf("invalid escape sequence in byte literal: '*%s'", raw[1:])
2326→ }
2327→ switch raw[1] {
2328→ case 'n':
2329→ return '\n', nil
2330→ case 'c':
2331→ return '\r', nil
2332→ case 't':
2333→ return '\t', nil
2334→ case 's':
2335→ return ' ', nil
2336→ case '*':
2337→ return '*', nil
2338→ case '\'':
2339→ return '\'', nil
2340→ case '"':
2341→ return '"', nil
2342→ default:
2343→ return 0, fmt.Errorf("unknown escape sequence in byte literal: '*%c'", raw[1])
2344→ }
2345→ }
2346→ if len(raw) != 1 {
2347→ return 0, fmt.Errorf("byte literal must be a single character, got %q", raw)
2348→ }
2349→ return raw[0], nil
2350→}
2351→
2352→func (p *Parser) parseFuncCallExpr() *ast.FuncCall {
2353→ call := &ast.FuncCall{
2354→ Token: p.curToken,
2355→ Name: p.curToken.Literal,
2356→ }{
"file_path": "/home/david/projects/code-associates/occam2go/parser/parser.go",
"limit": 30,
"offset": 2605
} 2605→ left = &ast.IntegerLiteral{Token: p.curToken, Value: val}
2606→ case lexer.TRUE:
2607→ left = &ast.BooleanLiteral{Token: p.curToken, Value: true}
2608→ case lexer.FALSE:
2609→ left = &ast.BooleanLiteral{Token: p.curToken, Value: false}
2610→ case lexer.STRING:
2611→ left = &ast.StringLiteral{Token: p.curToken, Value: p.curToken.Literal}
2612→ case lexer.BYTE_LIT:
2613→ b, err := p.parseByteLiteralValue(p.curToken.Literal)
2614→ if err != nil {
2615→ p.addError(err.Error())
2616→ return nil
2617→ }
2618→ left = &ast.ByteLiteral{Token: p.curToken, Value: b}
2619→ case lexer.LPAREN:
2620→ p.nextToken()
2621→ left = p.parseExpression(LOWEST)
2622→ if !p.expectPeek(lexer.RPAREN) {
2623→ return nil
2624→ }
2625→ case lexer.MINUS, lexer.MINUS_KW:
2626→ token := p.curToken
2627→ p.nextToken()
2628→ left = &ast.UnaryExpr{
2629→ Token: token,
2630→ Operator: "-",
2631→ Right: p.parseExpression(PREFIX),
2632→ }
2633→ case lexer.NOT:
2634→ token := p.curTokenNow let me also check the course module's out_string to understand how it works and confirm that it sends bytes one-by-one through the channel.
Let me also check how out.string is implemented in the course module, and look at the FLUSH handling.
{
"pattern": "PROC out\\.string|PROC out\\.ch|PROC flush",
"path": "/home/david/projects/code-associates/occam2go/kroc/modules/course/libsrc/utils.occ",
"output_mode": "content",
"-n": true,
"-A": 10
}45:--{{{ PROC out.ch (VAL BYTE ch, VAL INT field, CHAN BYTE out!)
46---* Write a character to a channel.
47--- This outputs [@code ch] in a fieldwidth [@code field] down [@code out]. If
48--- the fieldwidth is too wide for [@code ch], it right-justifies [@code ch]
49--- with spaces on the left. If the field is not wide enough, it prints the
50--- [@code ch] anyway. These rules for fieldwidth are the same as those used by
51--- the Pascal [@text write] procedure.
52--- @param ch Character
53--- @param field Field width to right-justify in
54--- @param out Channel to write to
55:PROC out.ch (VAL BYTE ch, VAL INT field, CHAN BYTE out!)
56- --{{{
57- SEQ
58- out.repeat (' ', field - 1, out!)
59- out ! ch
60- --}}}
61-:
62---}}}
63:--{{{ PROC out.string (VAL []BYTE s, VAL INT field, CHAN BYTE out!)
64---* Write a string to a channel.
65--- This outputs [@code s] in a fieldwidth [@code field] down [@code out].
66--- @param s String
67--- @param field Field width to right-justify in
68--- @param out Channel to write to
69:PROC out.string (VAL []BYTE s, VAL INT field, CHAN BYTE out!)
70- --{{{
71- VAL INT length IS SIZE s:
72- SEQ
73- out.repeat (' ', field - length, out!)
74- SEQ i = 0 FOR length
75- out ! s[i]
76- --}}}
77-:
78---}}}
79---{{{ PROC out.byte (VAL BYTE b, VAL INT field, CHAN BYTE out!)
--
250:--{{{ PROC flush (CHAN BYTE out!)
251---* Flush an output channel.
252--- If [@code out] is (ultimately) connected to the external [@text stdout] or
253--- [@text stderr] channel, this forces UNIX to flush all outstanding output to
254--- that file descriptor. UNIX normally buffers this character output on a
255--- line-by-line basis.
256--- @param out Channel to write to
257:PROC flush (CHAN BYTE out!)
258- --{{{
259- out ! FLUSH
260- --}}}
261-:
262---}}}
263---}}}
264---{{{ in stuff
265---{{{ PROC in.skip (BYTE ch, CHAN BYTE in?)
266---* Discard whitespace.
267--- This inputs from [@code in] until a non-space character is found. The{
"pattern": "VAL BYTE FLUSH|VAL BYTE NULL",
"path": "/home/david/projects/code-associates/occam2go/kroc/modules/course/libsrc/consts.inc",
"output_mode": "content"
}Now I have a complete understanding. Let me look at one more thing - the existing e2e test helpers to understand how they generate runnable programs, so I know how to write a new e2e test for the course module programs.
{
"file_path": "/home/david/projects/code-associates/occam2go/codegen/e2e_helpers_test.go"
} 1→package codegen
2→
3→import (
4→ "os"
5→ "os/exec"
6→ "path/filepath"
7→ "testing"
8→
9→ "github.com/codeassociates/occam2go/lexer"
10→ "github.com/codeassociates/occam2go/parser"
11→ "github.com/codeassociates/occam2go/preproc"
12→)
13→
14→// transpileCompileRun takes Occam source, transpiles to Go, compiles, runs,
15→// and returns the stdout output
16→func transpileCompileRun(t *testing.T, occamSource string) string {
17→ t.Helper()
18→
19→ // Transpile
20→ l := lexer.New(occamSource)
21→ p := parser.New(l)
22→ program := p.ParseProgram()
23→
24→ if len(p.Errors()) > 0 {
25→ for _, err := range p.Errors() {
26→ t.Errorf("parser error: %s", err)
27→ }
28→ t.FailNow()
29→ }
30→
31→ gen := New()
32→ goCode := gen.Generate(program)
33→
34→ // Create temp directory for this test
35→ tmpDir, err := os.MkdirTemp("", "occam2go-test-*")
36→ if err != nil {
37→ t.Fatalf("failed to create temp dir: %v", err)
38→ }
39→ defer os.RemoveAll(tmpDir)
40→
41→ // Write Go source
42→ goFile := filepath.Join(tmpDir, "main.go")
43→ if err := os.WriteFile(goFile, []byte(goCode), 0644); err != nil {
44→ t.Fatalf("failed to write Go file: %v", err)
45→ }
46→
47→ // Compile
48→ binFile := filepath.Join(tmpDir, "main")
49→ compileCmd := exec.Command("go", "build", "-o", binFile, goFile)
50→ compileOutput, err := compileCmd.CombinedOutput()
51→ if err != nil {
52→ t.Fatalf("compilation failed: %v\nOutput: %s\nGo code:\n%s", err, compileOutput, goCode)
53→ }
54→
55→ // Run
56→ runCmd := exec.Command(binFile)
57→ output, err := runCmd.CombinedOutput()
58→ if err != nil {
59→ t.Fatalf("execution failed: %v\nOutput: %s", err, output)
60→ }
61→
62→ return string(output)
63→}
64→
65→// transpileCompileRunFromFile takes an occam file path, preprocesses it,
66→// then transpiles, compiles, and runs.
67→func transpileCompileRunFromFile(t *testing.T, mainFile string, includePaths []string) string {
68→ t.Helper()
69→
70→ pp := preproc.New(preproc.WithIncludePaths(includePaths))
71→ expanded, err := pp.ProcessFile(mainFile)
72→ if err != nil {
73→ t.Fatalf("preprocessor error: %v", err)
74→ }
75→ if len(pp.Errors()) > 0 {
76→ for _, e := range pp.Errors() {
77→ t.Errorf("preprocessor warning: %s", e)
78→ }
79→ }
80→
81→ return transpileCompileRun(t, expanded)
82→}
83→{
"pattern": "course|hello_world|transpileCompileRunFromFile",
"path": "/home/david/projects/code-associates/occam2go/codegen",
"glob": "*_test.go",
"output_mode": "content",
"-n": true
}codegen/e2e_helpers_test.go:65:// transpileCompileRunFromFile takes an occam file path, preprocesses it,
codegen/e2e_helpers_test.go:67:func transpileCompileRunFromFile(t *testing.T, mainFile string, includePaths []string) string {
codegen/e2e_preproc_test.go:25: output := transpileCompileRunFromFile(t, mainFile, nil)
codegen/e2e_preproc_test.go:45: output := transpileCompileRunFromFile(t, mainFile, nil)
codegen/e2e_preproc_test.go:69: output := transpileCompileRunFromFile(t, mainFile, nil){
"file_path": "/home/david/projects/code-associates/occam2go/codegen/codegen.go",
"limit": 45,
"offset": 1
} 1→package codegen
2→
3→import (
4→ "fmt"
5→ "strings"
6→
7→ "github.com/codeassociates/occam2go/ast"
8→)
9→
10→// Generator converts an AST to Go code
11→type Generator struct {
12→ indent int
13→ builder strings.Builder
14→ needSync bool // track if we need sync package import
15→ needFmt bool // track if we need fmt package import
16→ needTime bool // track if we need time package import
17→ needOs bool // track if we need os package import
18→ needMath bool // track if we need math package import
19→ needMathBits bool // track if we need math/bits package import
20→
21→ // Track procedure signatures for proper pointer handling
22→ procSigs map[string][]ast.ProcParam
23→ // Track current procedure's reference parameters
24→ refParams map[string]bool
25→
26→ // Protocol support
27→ protocolDefs map[string]*ast.ProtocolDecl
28→ chanProtocols map[string]string // channel name → protocol name
29→ tmpCounter int // for unique temp variable names
30→
31→ // Record support
32→ recordDefs map[string]*ast.RecordDecl
33→ recordVars map[string]string // variable name → record type name
34→
35→ // Nesting level: 0 = package level, >0 = inside a function
36→ nestingLevel int
37→
38→ // RETYPES parameter renames: when a RETYPES declaration shadows a
39→ // parameter (e.g. VAL INT X RETYPES X :), the parameter is renamed
40→ // in the signature so := can create a new variable with the original name.
41→ retypesRenames map[string]string
42→}
43→
44→// Transputer intrinsic function names
45→var transpIntrinsics = map[string]bool{# Plan: Get Course Module Example Programs to Compile and Run
## Context
The occam2go transpiler can transpile the full KRoC course module to Go code that passes `go vet`, but the output has no `main()` function and string escape sequences are not converted. This means no program that uses the course module can actually compile and run.
Two changes are needed:
1. **String escape sequences**: Occam uses `*c`, `*n`, `*t`, `*s`, `**`, `*"`, `*'` in string literals. These are currently passed through literally, so `"Hello World*c*n"` becomes `"Hello World*c*n"` in Go instead of `"Hello World\r\n"`.
2. **Main harness generation**: Occam programs define a PROC with the standard entry point signature `(CHAN BYTE keyboard?, screen!, error!)`. The transpiler needs to detect this and generate a `func main()` that wires stdin/stdout/stderr to channels and calls the entry PROC.
## Changes
### 1. Convert occam string escapes in the parser (`parser/parser.go`)
Add a `convertOccamStringEscapes(raw string) string` function (analogous to the existing `parseByteLiteralValue`) that converts occam escape sequences in string literals to their actual byte values:
- `*n` → `\n` (newline, byte 10)
- `*c` → `\r` (carriage return, byte 13)
- `*t` → `\t` (tab, byte 9)
- `*s` → ` ` (space, byte 32)
- `**` → `*` (literal asterisk)
- `*"` → `"` (literal double quote)
- `*'` → `'` (literal single quote)
Apply this conversion at line 2611 where `StringLiteral` nodes are created:
```go
case lexer.STRING:
left = &ast.StringLiteral{Token: p.curToken, Value: p.convertOccamStringEscapes(p.curToken.Literal)}
```
This way the AST stores the actual string content (with real escape bytes), and the existing `%q` formatting in codegen will produce correct Go string literals.
### 2. Generate main() harness for entry point PROCs (`codegen/codegen.go`)
In the `Generate()` function, after separating statements (around line 258), when `mainStatements` is empty but there are proc declarations:
1. **Detect the entry point**: Find the **last** top-level PROC whose parameters match the pattern: exactly 3 params, all `IsChan` with `ChanElemType == "BYTE"`, first has `ChanDir == "?"`, second and third have `ChanDir == "!"`.
2. **Generate the harness**: Emit a `func main()` that:
- Creates 3 buffered `chan byte` channels (keyboard, screen, error)
- Starts a **screen writer** goroutine: reads from screen channel, writes to `os.Stdout` via `bufio.Writer`, flushes on byte 255 (the FLUSH constant from course module)
- Starts an **error writer** goroutine: same pattern but writes to `os.Stderr`
- Starts a **keyboard reader** goroutine: reads from `os.Stdin` via `bufio.Reader`, sends bytes to keyboard channel
- Calls the entry PROC with the three channels
- Closes screen and error channels after the proc returns
- Waits for writer goroutines to finish draining via `sync.WaitGroup`
3. **Imports**: When generating the harness, ensure `os`, `sync`, and `bufio` are imported. Add a `needBufio` flag to the Generator struct.
### 3. Add tests
- **Parser test** (`parser/parser_test.go`): Test `convertOccamStringEscapes` with various escape sequences.
- **Codegen unit test** (`codegen/codegen_test.go`): Test that a string literal with `*n` produces a Go string with `\n`.
- **E2E test** (`codegen/e2e_test.go` or new file): Test hello_world.occ transpile → compile → run, verifying output is `Hello World\r\n`.
## Files to Modify
1. `parser/parser.go` — Add `convertOccamStringEscapes()`, use it at line 2611
2. `codegen/codegen.go` — Add entry point detection, main harness generation, `needBufio` flag, `bufio` import
3. `parser/parser_test.go` — Add string escape tests
4. `codegen/codegen_test.go` — Add string escape codegen test
5. `codegen/e2e_test.go` (or new e2e file) — Add hello_world course module e2e test
## Verification
```bash
# Unit tests
go test ./parser -run TestStringEscape
go test ./codegen -run TestStringEscape
# E2E: hello_world with course module
./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/hello_world.go kroc/modules/course/examples/hello_world.occ
go build -o /tmp/hello_world /tmp/hello_world.go
/tmp/hello_world # Should print "Hello World" and exit
# Ensure existing tests still pass
go test ./...
# Course module still passes go vet
./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/course_out.go kroc/modules/course/libsrc/course.module
go vet /tmp/course_out.go
```
{
"allowedPrompts": [
{
"tool": "Bash",
"prompt": "run tests"
},
{
"tool": "Bash",
"prompt": "build and run transpiler"
},
{
"tool": "Bash",
"prompt": "compile and run transpiled Go code"
}
],
"plan": "# Plan: Get Course Module Example Programs to Compile and Run\n\n## Context\n\nThe occam2go transpiler can transpile the full KRoC course module to Go code that passes `go vet`, but the output has no `main()` function and string escape sequences are not converted. This means no program that uses the course module can actually compile and run.\n\nTwo changes are needed:\n1. **String escape sequences**: Occam uses `*c`, `*n`, `*t`, `*s`, `**`, `*\"`, `*'` in string literals. These are currently passed through literally, so `\"Hello World*c*n\"` becomes `\"Hello World*c*n\"` in Go instead of `\"Hello World\\r\\n\"`.\n2. **Main harness generation**: Occam programs define a PROC with the standard entry point signature `(CHAN BYTE keyboard?, screen!, error!)`. The transpiler needs to detect this and generate a `func main()` that wires stdin/stdout/stderr to channels and calls the entry PROC.\n\n## Changes\n\n### 1. Convert occam string escapes in the parser (`parser/parser.go`)\n\nAdd a `convertOccamStringEscapes(raw string) string` function (analogous to the existing `parseByteLiteralValue`) that converts occam escape sequences in string literals to their actual byte values:\n- `*n` → `\\n` (newline, byte 10)\n- `*c` → `\\r` (carriage return, byte 13)\n- `*t` → `\\t` (tab, byte 9)\n- `*s` → ` ` (space, byte 32)\n- `**` → `*` (literal asterisk)\n- `*\"` → `\"` (literal double quote)\n- `*'` → `'` (literal single quote)\n\nApply this conversion at line 2611 where `StringLiteral` nodes are created:\n```go\ncase lexer.STRING:\n left = &ast.StringLiteral{Token: p.curToken, Value: p.convertOccamStringEscapes(p.curToken.Literal)}\n```\n\nThis way the AST stores the actual string content (with real escape bytes), and the existing `%q` formatting in codegen will produce correct Go string literals.\n\n### 2. Generate main() harness for entry point PROCs (`codegen/codegen.go`)\n\nIn the `Generate()` function, after separating statements (around line 258), when `mainStatements` is empty but there are proc declarations:\n\n1. **Detect the entry point**: Find the **last** top-level PROC whose parameters match the pattern: exactly 3 params, all `IsChan` with `ChanElemType == \"BYTE\"`, first has `ChanDir == \"?\"`, second and third have `ChanDir == \"!\"`.\n\n2. **Generate the harness**: Emit a `func main()` that:\n - Creates 3 buffered `chan byte` channels (keyboard, screen, error)\n - Starts a **screen writer** goroutine: reads from screen channel, writes to `os.Stdout` via `bufio.Writer`, flushes on byte 255 (the FLUSH constant from course module)\n - Starts an **error writer** goroutine: same pattern but writes to `os.Stderr`\n - Starts a **keyboard reader** goroutine: reads from `os.Stdin` via `bufio.Reader`, sends bytes to keyboard channel\n - Calls the entry PROC with the three channels\n - Closes screen and error channels after the proc returns\n - Waits for writer goroutines to finish draining via `sync.WaitGroup`\n\n3. **Imports**: When generating the harness, ensure `os`, `sync`, and `bufio` are imported. Add a `needBufio` flag to the Generator struct.\n\n### 3. Add tests\n\n- **Parser test** (`parser/parser_test.go`): Test `convertOccamStringEscapes` with various escape sequences.\n- **Codegen unit test** (`codegen/codegen_test.go`): Test that a string literal with `*n` produces a Go string with `\\n`.\n- **E2E test** (`codegen/e2e_test.go` or new file): Test hello_world.occ transpile → compile → run, verifying output is `Hello World\\r\\n`.\n\n## Files to Modify\n\n1. `parser/parser.go` — Add `convertOccamStringEscapes()`, use it at line 2611\n2. `codegen/codegen.go` — Add entry point detection, main harness generation, `needBufio` flag, `bufio` import\n3. `parser/parser_test.go` — Add string escape tests\n4. `codegen/codegen_test.go` — Add string escape codegen test\n5. `codegen/e2e_test.go` (or new e2e file) — Add hello_world course module e2e test\n\n## Verification\n\n```bash\n# Unit tests\ngo test ./parser -run TestStringEscape\ngo test ./codegen -run TestStringEscape\n\n# E2E: hello_world with course module\n./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/hello_world.go kroc/modules/course/examples/hello_world.occ\ngo build -o /tmp/hello_world /tmp/hello_world.go\n/tmp/hello_world # Should print \"Hello World\" and exit\n\n# Ensure existing tests still pass\ngo test ./...\n\n# Course module still passes go vet\n./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/course_out.go kroc/modules/course/libsrc/course.module\ngo vet /tmp/course_out.go\n```\n"
}The user doesn't want to proceed with this tool use. The tool use was rejected (eg. if it was a file edit, the new_string was NOT written to the file). STOP what you are doing and wait for the user to tell you how to proceed.