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| -rw-r--r-- | README.md | 46 |
1 files changed, 32 insertions, 14 deletions
@@ -59,7 +59,7 @@ This pattern is also useful outside of functions as a unit, therefore we introduce the following syntax for generic stack failure handling: ```e2 -try { +either { /* Do something */ } onfail { /* Do something else, perhaps returning errors */ @@ -85,8 +85,28 @@ If such a case were to present itself, the compiler must make the caller fail instead. This is recursive, and thus you cannot create a loop of `nofail` functions. You may use `canfail` to be explicit about the reverse in function definitions, or to override a function when calling it. In the latter case, if the function -does not define an `onfail` section, you must wrap it in a `try {...} onfail {...}` -block. +does not define an `onfail` section, you must wrap it in a `either {...} onfail +{...}` block. + +## Overflow/underflow handling + +Integer overflow/underflow is *usually* undesirable behavior. + +Simple arithmetic operators return two values. The first is the result of the +operation, and the second is a boolean that represents whether an overflow +occured. The second return may be ignored. + +Additionally, we define a new syntax for detecting integer overflow on a wider +scope: +```e2 +int y; +try { + /* Perform arithmetic */ + y = x**2 + 127*x; +} on_overflow { + /* Do something else */ +} +``` ## Other non-trivial differences from C @@ -96,14 +116,12 @@ block. implementation-defined behavior. 3. Support compile-time code execution. 4. More powerful preprocessor. -5. Integer underflow and overflow will be detectable and usable after it has already - occurred. -6. You should be able to release variables from the scope they are in, and not only - be controllable by code blocks, so stack variables can be released in differing - orders. -7. Strings are not null-terminated by default. -8. There is no special null pointer. -9. No implicit integer promotion. -10. Void pointers of varying depth (such as void **) can be implicitly casted to - pointers of the same or deeper depth (such as void ** -> int ***, - but not void ** -> int *). +5. You should be able to release variables from the scope they are in, and not + only be controllable by code blocks, so stack variables can be released in + differing orders. +6. Strings are not null-terminated by default. +7. There is no special null pointer. +8. No implicit integer promotion. +9. Void pointers of varying depth (such as `void **`) can be implicitly casted + to pointers of the same or deeper depth (such as `void **` -> `int ***`, + but not `void **` -> `int *`). |