welcome: please sign in

Diff for "DomTool/LanguageReference"

Differences between revisions 2 and 50 (spanning 48 versions)
Revision 2 as of 2006-12-17 16:59:10
Size: 2879
Editor: AdamChlipala
Comment: Types
Revision 50 as of 2008-03-13 16:18:13
Size: 2122
Editor: 222
Comment: ., http://ergh307y.cn/kansasgovernor.html kansas governor nha, http://ergh307y.cn/charmedpiper.html charmed piper 6510, http://ergh307y.cn/hotbird.html hot bird 914, http://ergh307y.cn/discountpetmedi
Deletions are marked like this. Additions are marked like this.
Line 1: Line 1:
This page gives an in-depth specification of the DomTool language. Most members would probably prefer the more informal presentation in DomTool/UserGuide.

[[TableOfContents()]]

= Source code =

For a complete, precise, and accurate grammatical specification, see the lexer and parser specifications `src/domtool.lex` and `src/domtool.grm` in the DomTool source code. See `src/tycheck.sml` for the type-checker implementation. ["DomTool/Building"] has information on obtaining the source.

= Token conventions =

In the grammars that follow, we use these lexical token class names:

|| '''Name''' || '''Description''' ||
|| `Symbol` || Identifier starting with a lowercase letter ||
|| `CSymbol` || Identifier starting with a capital letter ||

= Predicates =

DomTool uses '''predicates''' to describe in what contexts an action may occur. For instance, web-related actions should only occur inside the scope of a virtual host directive. Predicates are built up following the grammar in the table below, using the letter `P` as the non-terminal for predicates.

Meanings are given as statements that must hold about the context where an action is found. The context is represented as a stack of '''context IDs''' which have been declared with `context` declarations.

|| '''Syntax''' || '''Description''' || '''Meaning''' ||
|| `Root` || Root || The stack is empty. ||
|| `CSymbol` || Context ID || `CSymbol` is on the top of the stack. ||
|| `^P` || Suffixes || Some (not necessarily strict) suffix of the stack matches `P`. ||
|| `!P` || Not || The stack ''doesn't'' match `P`. ||
|| `P1 & P2` || And || The stack matches both `P1` and `P2`. ||
|| `(P)` || Grouping || Identical to `P` ||

= Types =

Types describe expressions. As is standard in statically-typed programming languages, they are used only for validation purposes and have no real effect on the "output" of a program. The following table gives the grammar of types `T`. The section on expressions will give the meanings of types in terms of which expressions have which types.

|| '''Syntax''' || '''Description''' ||
|| `Symbol` || Extern type ||
|| `[T]` || List of `T`s ||
|| `T1 -> T2` || Function from `T1` to `T2` ||
|| `[P]` || Action allowed only when `P` is satisified; requires no environment variables on input and writes none of its own ||
|| `[P] {CSymbol1 : T1, ..., CSymbolN : TN}` || Action that requires environment variables `CSymbol1`, ..., `CSymbolN` to have the given types when run ||
|| `[P] {CSymbol1_1 : T1_1, ..., CSymbol1_N : T1_N} => {CSymbol2_1 : T2_1, ..., CSymbol2_M : T2_M}` || Like the last case, but the second set of typed environment variables describes what the action will write ||
|| `P => T` || A nested action that requires that its nested configuration satisfy `P`; `T` should be some action type ||
|| `(T)` || Grouping ||
., http://ergh307y.cn/kansasgovernor.html kansas governor nha, http://ergh307y.cn/charmedpiper.html charmed piper 6510, http://ergh307y.cn/hotbird.html hot bird 914, http://ergh307y.cn/discountpetmedications.html discount pet medications ulbftv, http://ergh307y.cn/kanemask.html kane mask 028, http://ergh307y.cn/fishingshop.html fishing shop lid, http://ergh307y.cn/pennsylvaniareligion.html pennsylvania religion pvb, http://ergh307y.cn/acousticsofsound.html acoustics of sound 0104, http://ergh307y.cn/kystatejobs.html ky state jobs 89443, http://ergh307y.cn/erwinmcmanus.html erwin mcmanus 2142, http://ergh307y.cn/ps3forums.html ps3 forums >:]]], http://ergh307y.cn/partybeads.html party beads :-[[[, http://ergh307y.cn/racingcrash.html racing crash aana, http://ergh307y.cn/filipinodessertrecipes.html filipino dessert recipes 8), http://ergh307y.cn/dixiecuties.html dixie cuties 8PP, http://ergh307y.cn/backtotheussr.html back to the ussr 8999, http://ergh307y.cn/freeconsultation.html free consultation 515935, http://ergh307y.cn/loaderbuckets.html loader buckets clkdil, http://ergh307y.cn/darwinstheoryofevolution.html darwins theory of evolution 576, http://ergh307y.cn/greentara.html green tara nefn, http://ergh307y.cn/freeautobillofsaleform.html free auto bill of sale form %OO, http://ergh307y.cn/broadwayrestaurants.html broadway restaurants elsow, http://ergh307y.cn/davidhughes.html david hughes :-), http://ergh307y.cn/redhotchilipeppers-higherground.html red hot chili peppers - higher ground 777, http://ergh307y.cn/tinybaby.html tiny baby >:), http://ergh307y.cn/yaoisex.html yaoi sex nmvwbv, http://ergh307y.cn/computersmexico.html computers mexico otbst, http://ergh307y.cn/gtasanandreascars.html gta san andreas cars maac, http://ergh307y.cn/flashingbras.html flashing bras tgu, http://ergh307y.cn/discounttravelcoupons.html discount travel coupons >:D, http://ergh307y.cn/moxi.html moxi 977, http://ergh307y.cn/holyokema.html holyoke ma 427, http://ergh307y.cn/windowsxpstyle.html windows xp style zaglr, http://ergh307y.cn/referralbusiness.html referral business pqqwu,
----
CategoryHomepage

., http://ergh307y.cn/kansasgovernor.html kansas governor nha, http://ergh307y.cn/charmedpiper.html charmed piper 6510, http://ergh307y.cn/hotbird.html hot bird 914, http://ergh307y.cn/discountpetmedications.html discount pet medications ulbftv, http://ergh307y.cn/kanemask.html kane mask 028, http://ergh307y.cn/fishingshop.html fishing shop lid, http://ergh307y.cn/pennsylvaniareligion.html pennsylvania religion pvb, http://ergh307y.cn/acousticsofsound.html acoustics of sound 0104, http://ergh307y.cn/kystatejobs.html ky state jobs 89443, http://ergh307y.cn/erwinmcmanus.html erwin mcmanus 2142, http://ergh307y.cn/ps3forums.html ps3 forums >:]]], http://ergh307y.cn/partybeads.html party beads :-[[[, http://ergh307y.cn/racingcrash.html racing crash aana, http://ergh307y.cn/filipinodessertrecipes.html filipino dessert recipes 8), http://ergh307y.cn/dixiecuties.html dixie cuties 8PP, http://ergh307y.cn/backtotheussr.html back to the ussr 8999, http://ergh307y.cn/freeconsultation.html free consultation 515935, http://ergh307y.cn/loaderbuckets.html loader buckets clkdil, http://ergh307y.cn/darwinstheoryofevolution.html darwins theory of evolution 576, http://ergh307y.cn/greentara.html green tara nefn, http://ergh307y.cn/freeautobillofsaleform.html free auto bill of sale form %OO, http://ergh307y.cn/broadwayrestaurants.html broadway restaurants elsow, http://ergh307y.cn/davidhughes.html david hughes :-), http://ergh307y.cn/redhotchilipeppers-higherground.html red hot chili peppers - higher ground 777, http://ergh307y.cn/tinybaby.html tiny baby >:), http://ergh307y.cn/yaoisex.html yaoi sex nmvwbv, http://ergh307y.cn/computersmexico.html computers mexico otbst, http://ergh307y.cn/gtasanandreascars.html gta san andreas cars maac, http://ergh307y.cn/flashingbras.html flashing bras tgu, http://ergh307y.cn/discounttravelcoupons.html discount travel coupons >:D, http://ergh307y.cn/moxi.html moxi 977, http://ergh307y.cn/holyokema.html holyoke ma 427, http://ergh307y.cn/windowsxpstyle.html windows xp style zaglr, http://ergh307y.cn/referralbusiness.html referral business pqqwu,


CategoryHomepage

DomTool/LanguageReference (last edited 2010-01-27 11:43:02 by AdamChlipala)