diff options
author | Eduardo Julian | 2017-05-03 17:22:04 -0400 |
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committer | Eduardo Julian | 2017-05-03 17:22:04 -0400 |
commit | 3f146f8372758c39ece0b9a4c19f4f408e8400ea (patch) | |
tree | 77c98ab383879d199e8b8e5f5265767d093a81e3 /new-luxc/source/luxc/parser.lux | |
parent | 3175ae85d62ff6f692b8cc127f56c6569041d788 (diff) |
- Made some changes in the way the parser works.
Diffstat (limited to '')
-rw-r--r-- | new-luxc/source/luxc/parser.lux | 122 |
1 files changed, 59 insertions, 63 deletions
diff --git a/new-luxc/source/luxc/parser.lux b/new-luxc/source/luxc/parser.lux index 4ca97a80a..6565ba65f 100644 --- a/new-luxc/source/luxc/parser.lux +++ b/new-luxc/source/luxc/parser.lux @@ -48,34 +48,33 @@ ## It operates recursively in order to produce the longest continuous ## chunk of white-space. (def: (space^ where) - (-> Cursor (Lexer [Text Cursor])) + (-> Cursor (Lexer [Cursor Text])) (do Monad<Lexer> [head (l;some' (l;one-of white-space))] ## New-lines must be handled as a separate case to ensure line ## information is handled properly. (l;either (l;after (l;one-of new-line) (do @ - [[tail end] (space^ (|> where + [[end tail] (space^ (|> where (update@ #;line n.inc) (set@ #;column +0)))] - (wrap [(format head tail) - end]))) - (wrap [head - (|> where - (update@ #;column (n.+ (text;size head))))])))) + (wrap [end + (format head tail)]))) + (wrap [(update@ #;column (n.+ (text;size head)) where) + head])))) ## Single-line comments can start anywhere, but only go up to the ## next new-line. (def: (single-line-comment^ where) - (-> Cursor (Lexer [Text Cursor])) + (-> Cursor (Lexer [Cursor Text])) (do Monad<Lexer> [_ (l;text "##") comment (l;some' (l;none-of new-line)) _ (l;text new-line)] - (wrap [comment - (|> where + (wrap [(|> where (update@ #;line n.inc) - (set@ #;column +0))]))) + (set@ #;column +0)) + comment]))) ## This is just a helper parser to find text which doesn't run into ## any special character sequences for multi-line comments. @@ -92,12 +91,11 @@ ## That is, any nested comment must have matched delimiters. ## Unbalanced comments ought to be rejected as invalid code. (def: (multi-line-comment^ where) - (-> Cursor (Lexer [Text Cursor])) + (-> Cursor (Lexer [Cursor Text])) (do Monad<Lexer> [_ (l;text "#(")] (loop [comment "" - where (|> where - (update@ #;column (n.+ +2)))] + where (update@ #;column (n.+ +2) where)] ($_ l;either ## These are normal chunks of commented text. (do @ @@ -120,15 +118,14 @@ ## That is why the sub-comment is covered in delimiters ## and then appended to the rest of the comment text. (do @ - [[sub-comment sub-where] (multi-line-comment^ where)] + [[sub-where sub-comment] (multi-line-comment^ where)] (recur (format comment "#(" sub-comment ")#") sub-where)) ## Finally, this is the rule for closing the comment. (do @ [_ (l;text ")#")] - (wrap [comment - (|> where - (update@ #;column (n.+ +2)))])) + (wrap [(update@ #;column (n.+ +2) where) + comment])) )))) ## This is the only parser that should be used directly by other @@ -138,7 +135,7 @@ ## from being used in any situation (alternatively, forcing one type ## of comment to be the only usable one). (def: (comment^ where) - (-> Cursor (Lexer [Text Cursor])) + (-> Cursor (Lexer [Cursor Text])) (l;either (single-line-comment^ where) (multi-line-comment^ where))) @@ -149,10 +146,10 @@ (def: (left-padding^ where) (-> Cursor (Lexer Cursor)) (l;either (do Monad<Lexer> - [[comment where] (comment^ where)] + [[where comment] (comment^ where)] (left-padding^ where)) (do Monad<Lexer> - [[white-space where] (space^ where)] + [[where white-space] (space^ where)] (wrap where)) )) @@ -211,7 +208,7 @@ ## standard library to actually produce the values from the literals. (do-template [<name> <tag> <lexer> <codec>] [(def: #export (<name> where) - (-> Cursor (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) (do Monad<Lexer> [chunk <lexer>] (case (:: <codec> decode chunk) @@ -219,9 +216,8 @@ (l;fail error) (#;Right value) - (wrap [[where (<tag> value)] - (|> where - (update@ #;column (n.+ (text;size chunk))))]))))] + (wrap [(update@ #;column (n.+ (text;size chunk)) where) + [where (<tag> value)]]))))] [parse-bool #;BoolS (l;either (l;text "true") (l;text "false")) @@ -253,18 +249,17 @@ ## This parser doesn't delegate the work of producing the value to a ## codec, since the raw-char^ parser already takes care of that magic. (def: #export (parse-char where) - (-> Cursor (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) (do Monad<Lexer> [[chunk value] (l;enclosed ["#\"" "\""] raw-char^)] - (wrap [[where (#;CharS value)] - (|> where - (update@ #;column (|>. ($_ n.+ +3 (text;size chunk)))))]))) + (wrap [(update@ #;column (|>. ($_ n.+ +3 (text;size chunk))) where) + [where (#;CharS value)]]))) ## This parser looks so complex because text in Lux can be multi-line ## and there are rules regarding how this is handled. (def: #export (parse-text where) - (-> Cursor (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) (do Monad<Lexer> [## Lux text "is delimited by double-quotes", as usual in most ## programming languages. @@ -277,7 +272,7 @@ ## This helps ensure that the formatting on the text in the ## source-code matches the formatting of the Text value. #let [offset-column (n.inc (get@ #;column where))] - [text-read where'] (: (Lexer [Text Cursor]) + [where' text-read] (: (Lexer [Cursor Text]) ## I must keep track of how much of the ## text body has been read, how far the ## cursor has progressed, and whether I'm @@ -332,9 +327,8 @@ ## reaches the right-delimiter. (do @ [_ (l;text "\"")] - (wrap [text-read - (|> where - (update@ #;column n.inc))])))) + (wrap [(update@ #;column n.inc where) + text-read])))) ## If a new-line is ## encountered, it gets ## appended to the value and @@ -347,8 +341,8 @@ (update@ #;line n.inc) (set@ #;column +0)) true)))))] - (wrap [[where (#;TextS text-read)] - where']))) + (wrap [where' + [where (#;TextS text-read)]]))) ## Form and tuple syntax is mostly the same, differing only in the ## delimiters involved. @@ -356,17 +350,17 @@ (do-template [<name> <tag> <open> <close>] [(def: (<name> where parse-ast) (-> Cursor - (-> Cursor (Lexer [AST Cursor])) - (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) + (Lexer [Cursor AST])) (do Monad<Lexer> [_ (l;text <open>) - [elems where'] (loop [elems (: (V;Vector AST) + [where' elems] (loop [elems (: (V;Vector AST) V;empty) where where] (l;either (do @ [## Must update the cursor as I ## go along, to keep things accurate. - [elem where'] (parse-ast where)] + [where' elem] (parse-ast where)] (recur (V;add elem elems) where')) (do @ @@ -375,11 +369,10 @@ ## end-delimiter. where' (left-padding^ where) _ (l;text <close>)] - (wrap [(V;to-list elems) - (|> where' - (update@ #;column n.inc))]))))] - (wrap [[where (<tag> elems)] - where'])))] + (wrap [(update@ #;column n.inc where') + (V;to-list elems)]))))] + (wrap [where' + [where (<tag> elems)]])))] [parse-form #;FormS "(" ")"] [parse-tuple #;TupleS "[" "]"] @@ -396,26 +389,25 @@ ## macros. (def: (parse-record where parse-ast) (-> Cursor - (-> Cursor (Lexer [AST Cursor])) - (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) + (Lexer [Cursor AST])) (do Monad<Lexer> [_ (l;text "{") - [elems where'] (loop [elems (: (V;Vector [AST AST]) + [where' elems] (loop [elems (: (V;Vector [AST AST]) V;empty) where where] (l;either (do @ - [[key where'] (parse-ast where) - [val where'] (parse-ast where')] + [[where' key] (parse-ast where) + [where' val] (parse-ast where')] (recur (V;add [key val] elems) where')) (do @ [where' (left-padding^ where) _ (l;text "}")] - (wrap [(V;to-list elems) - (|> where' - (update@ #;column n.inc))]))))] - (wrap [[where (#;RecordS elems)] - where']))) + (wrap [(update@ #;column n.inc where') + (V;to-list elems)]))))] + (wrap [where' + [where (#;RecordS elems)]]))) ## The parts of an identifier are separated by a single mark. ## E.g. module;name. @@ -506,19 +498,18 @@ ## construction and de-structuring (during pattern-matching). (do-template [<name> <tag> <lexer> <extra>] [(def: #export (<name> where) - (-> Cursor (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) (do Monad<Lexer> [[value length] <lexer>] - (wrap [[where (<tag> value)] - (|> where - (update@ #;column (|>. ($_ n.+ <extra> length))))])))] + (wrap [(update@ #;column (|>. ($_ n.+ <extra> length)) where) + [where (<tag> value)]])))] [parse-symbol #;SymbolS ident^ +0] [parse-tag #;TagS (l;after (l;char #"#") ident^) +1] ) (def: (parse-ast where) - (-> Cursor (Lexer [AST Cursor])) + (-> Cursor (Lexer [Cursor AST])) (do Monad<Lexer> [where (left-padding^ where)] ($_ l;either @@ -536,6 +527,11 @@ (parse-text where) ))) -(def: #export (parse where code) - (-> Cursor Text (Error [Text AST Cursor])) - (l;run' code (parse-ast where))) +(def: #export (parse [where code]) + (-> [Cursor Text] (Error [[Cursor Text] AST])) + (case (l;run' code (parse-ast where)) + (#E;Error error) + (#E;Error error) + + (#E;Success [remaining [where' output]]) + (#E;Success [[where' remaining] output]))) |