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Diffstat (limited to 'AGENTS/PITFALLS.md')
| -rw-r--r-- | AGENTS/PITFALLS.md | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/AGENTS/PITFALLS.md b/AGENTS/PITFALLS.md index acf21d2..6d1b196 100644 --- a/AGENTS/PITFALLS.md +++ b/AGENTS/PITFALLS.md @@ -5,8 +5,6 @@ Every bullet below was confirmed against the source, most also by compiling and running test programs. -- **STRING `=` / `<>` compares pointer identity, not contents.** No strcmp anywhere; - two equal heap strings compare unequal. - **OUTPUT takes exactly one expression.** `OUTPUT a, ", ", b` prints `a`, then the stray `, ", ", b` produces parse errors (recovery resyncs at the next statement start, so following statements survive; the compile still fails). Concatenate with @@ -48,10 +46,9 @@ test programs. keywords now — `DECLARE READ : INTEGER` no longer compiles. `WRITEFILE f, a, b` takes exactly two operands (the stray `, b` is a parse error, like multi-expression OUTPUT). READFILE's target must be a plain STRING variable — no CHAR, no `arr[i]` (mirrors - INPUT). The CIE guide's empty-line test `IF LineOfText = ""` silently fails here - because STRING `=` is pointer identity — use `LENGTH(LineOfText) = 0`. At most 16 - files open at once. All runtime misuse (not open, wrong mode, reopen, fopen failure, - READFILE past EOF) is a `[Fatal] line %d:` exit(1), by design — guard reads with + INPUT). The CIE guide's empty-line test `IF LineOfText = ""` compares contents. + At most 16 files open at once. All runtime misuse (not open, wrong mode, reopen, + fopen failure, READFILE past EOF) is a `[Fatal] line %d:` exit(1), by design — guard reads with `WHILE NOT EOF(...)`. Caveat: the open-file table is keyed by the filename *string* (per CIE semantics), so two spellings of one OS path (`"a.txt"` vs `"./a.txt"`) evade the already-open check and get two independent buffered streams — reads through the |