Fold BinaryExpr subtrees whose operands reduce to INT or STRING
literals at compile time. `10 * 2 + 5` now emits a single PushInt(25)
instead of three VM ops; `"a" + "b"` collapses to "ab". Overflowing
INTs and SLASH (which Harbour turns into double) fall through to the
VM so semantics stay intact.
Implementation is a bottom-up foldLiteralTree pre-pass on each
BinaryExpr, plus a tryFoldBinary matcher for the leaf case. Mutates
the AST in place — safe because the generator owns the tree after
parse.
Bench numbers don't move (SQL paths have no literal-only arithmetic
in hot loops), but generated code shrinks on PRG that uses #define
constants for widths / offsets / factors.
Verification
- go test ./... ALL PASS
- FiveSql2 test_sql1999 43/43
- tests/compat_harbour 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
CharlesKWON
a0acdf0289