diff options
| author | Marshall Lochbaum <mwlochbaum@gmail.com> | 2020-06-26 20:10:27 -0400 |
|---|---|---|
| committer | Marshall Lochbaum <mwlochbaum@gmail.com> | 2020-06-26 20:10:27 -0400 |
| commit | 55b3298701bcd1e3b5c4c2b4383f823511560f1c (patch) | |
| tree | a58102fd5b2cd8e7ecf0eb765e4e2397773eedf7 /spec | |
| parent | c2c2565305d723269ebb28e0c2105bb0712dfeee (diff) | |
Prevent function versus value header ambiguity
Diffstat (limited to 'spec')
| -rw-r--r-- | spec/grammar.md | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/spec/grammar.md b/spec/grammar.md index 691b8c56..8a20deee 100644 --- a/spec/grammar.md +++ b/spec/grammar.md @@ -15,8 +15,8 @@ Here we define the "atomic" forms of functions and operators, which are either s _comp_ = _c_ | _cl_ | "(" _cmpExp_ ")" | _brComp_ _mod = _m | _ml | "(" _modExpr ")" | _brMod Func = F | Fl | "(" FuncExpr ")" | BrFunc - atom = v | vl | "(" valExpr ")" | brVal - | "⟨" ⋄? ( ( EXPR ⋄ )* EXPR ⋄? )? "⟩" + atom = v | vl | "(" valExpr ")" | brVal | list + list = "⟨" ⋄? ( ( EXPR ⋄ )* EXPR ⋄? )? "⟩" value = atom | ANY ( "‿" ANY )+ Starting at the highest-order objects, modifiers and compositions have fairly simple syntax. In most cases the syntax for `←` and `↩` is the same, but only `↩` can be used for modified assignment. @@ -58,7 +58,7 @@ Value expressions are complicated by the possibility of list assignment. We also lhs = lhsValue | lhsStr valExpr = arg | lhs ASGN valExpr - | lhs Derv "↩" valExpr ⍝ Modified assignment + | lhs Derv "↩" valExpr ⍝ Modified assignment A header looks like a name for the thing being headed, or its application to inputs (possibly twice in the case of modifiers and compositions). As with assignment, it is restricted to a simple form with no extra parentheses. The full list syntax is allowed for arguments. As a special rule, a function header specifically can omit the function. @@ -69,7 +69,8 @@ A header looks like a name for the thing being headed, or its application to inp ModH1 = HeadF ( _m | "_𝕣" ) CmpH1 = HeadF ( _c_ | "_𝕣_" ) HeadG valHead = v - FuncHead = F | ( headW? ( F | "𝕊" ) )? headX + FuncHead = F | headW? ( F | "𝕊" ) headX + | vl | "(" valExpr ")" | brVal | list ⍝ value but not v _modHead = _m | ModH1 | headW? ModH1 headX _cmpHed_ = _c_ | CmpH1 | headW? CmpH1 headX |