diff options
Diffstat (limited to 'new-luxc/source')
| -rw-r--r-- | new-luxc/source/luxc/parser.lux | 123 |
1 files changed, 82 insertions, 41 deletions
diff --git a/new-luxc/source/luxc/parser.lux b/new-luxc/source/luxc/parser.lux index d061fdda5..bc70dfe91 100644 --- a/new-luxc/source/luxc/parser.lux +++ b/new-luxc/source/luxc/parser.lux @@ -24,7 +24,6 @@ ## Lux Code nodes/tokens are annotated with cursor meta-data ## (file-name, line, column) to keep track of their provenance and ## location, which is helpful for documentation and debugging. - (;module: lux (lux (control monad @@ -218,42 +217,84 @@ (wrap [(update@ #;column (n.+ (text;size chunk)) where) [where (<tag> value)]]))))] - [parse-bool #;Bool + [bool #;Bool (p;either (marker^ "true") (marker^ "false")) bool;Codec<Text,Bool>] - [parse-nat #;Nat + [nat #;Nat (l;seq (l;one-of "+") rich-digits^) number;Codec<Text,Nat>] - [parse-int #;Int + [int #;Int (l;seq (p;default "" (l;one-of "-")) rich-digits^) number;Codec<Text,Int>] - [parse-frac #;Frac - ($_ l;seq - (p;default "" (l;one-of "-")) - rich-digits^ - (l;one-of ".") - rich-digits^ - (p;default "" - ($_ l;seq - (l;one-of "eE") - (p;default "" (l;one-of "+-")) - (l;many l;decimal)))) - number;Codec<Text,Frac>] - - [parse-deg #;Deg + [deg #;Deg (l;seq (l;one-of ".") rich-digits^) number;Codec<Text,Deg>] ) +(def: (normal-frac where) + (-> Cursor (l;Lexer [Cursor Code])) + (do p;Monad<Parser> + [chunk ($_ l;seq + (p;default "" (l;one-of "-")) + rich-digits^ + (l;one-of ".") + rich-digits^ + (p;default "" + ($_ l;seq + (l;one-of "eE") + (p;default "" (l;one-of "+-")) + rich-digits^)))] + (case (:: number;Codec<Text,Frac> decode chunk) + (#;Left error) + (p;fail error) + + (#;Right value) + (wrap [(update@ #;column (n.+ (text;size chunk)) where) + [where (#;Frac value)]])))) + +(def: frac-ratio-fragment + (l;Lexer Frac) + (<| (p;codec number;Codec<Text,Frac>) + (:: p;Monad<Parser> map (function [digits] + (format digits ".0"))) + rich-digits^)) + +(def: (ratio-frac where) + (-> Cursor (l;Lexer [Cursor Code])) + (do p;Monad<Parser> + [chunk ($_ l;seq + (p;default "" (l;one-of "-")) + rich-digits^ + (l;one-of "/") + rich-digits^) + value (l;local chunk + (do @ + [signed? (l;this? "-") + numerator frac-ratio-fragment + _ (l;this? "/") + denominator frac-ratio-fragment + _ (p;assert "Denominator cannot be 0." + (not (f.= 0.0 denominator)))] + (wrap (|> numerator + (f.* (if signed? -1.0 1.0)) + (f./ denominator)))))] + (wrap [(update@ #;column (n.+ (text;size chunk)) where) + [where (#;Frac value)]]))) + +(def: #export (frac where) + (-> Cursor (l;Lexer [Cursor Code])) + (p;either (normal-frac where) + (ratio-frac where))) + ## 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) +(def: #export (text where) (-> Cursor (l;Lexer [Cursor Code])) (do p;Monad<Parser> [## Lux text "is delimited by double-quotes", as usual in most @@ -343,7 +384,7 @@ ## delimiters involved. ## They may have an arbitrary number of arbitrary Code nodes as elements. (do-template [<name> <tag> <open> <close>] - [(def: (<name> where parse-ast) + [(def: (<name> where ast) (-> Cursor (-> Cursor (l;Lexer [Cursor Code])) (l;Lexer [Cursor Code])) @@ -355,7 +396,7 @@ (p;either (do @ [## Must update the cursor as I ## go along, to keep things accurate. - [where' elem] (parse-ast where)] + [where' elem] (ast where)] (recur (V;add elem elems) where')) (do @ @@ -369,8 +410,8 @@ (wrap [where' [where (<tag> elems)]])))] - [parse-form #;Form "(" ")"] - [parse-tuple #;Tuple "[" "]"] + [form #;Form "(" ")"] + [tuple #;Tuple "[" "]"] ) ## Records are almost (syntactically) the same as forms and tuples, @@ -382,7 +423,7 @@ ## Code node, however, record Code nodes allow any Code node to occupy ## this position, since it may be useful when processing Code syntax in ## macros. -(def: (parse-record where parse-ast) +(def: (record where ast) (-> Cursor (-> Cursor (l;Lexer [Cursor Code])) (l;Lexer [Cursor Code])) @@ -392,8 +433,8 @@ V;empty) where where] (p;either (do @ - [[where' key] (parse-ast where) - [where' val] (parse-ast where')] + [[where' key] (ast where) + [where' val] (ast where')] (recur (V;add [key val] elems) where')) (do @ @@ -498,31 +539,31 @@ (wrap [(update@ #;column (|>. ($_ n.+ <extra> length)) where) [where (<tag> value)]])))] - [parse-symbol #;Symbol ident^ +0] - [parse-tag #;Tag (p;after (l;this "#") ident^) +1] + [symbol #;Symbol ident^ +0] + [tag #;Tag (p;after (l;this "#") ident^) +1] ) -(def: (parse-ast where) +(def: (ast where) (-> Cursor (l;Lexer [Cursor Code])) (do p;Monad<Parser> [where (left-padding^ where)] ($_ p;either - (parse-form where parse-ast) - (parse-tuple where parse-ast) - (parse-record where parse-ast) - (parse-bool where) - (parse-nat where) - (parse-frac where) - (parse-int where) - (parse-deg where) - (parse-symbol where) - (parse-tag where) - (parse-text where) + (form where ast) + (tuple where ast) + (record where ast) + (bool where) + (nat where) + (frac where) + (int where) + (deg where) + (symbol where) + (tag where) + (text where) ))) (def: #export (parse [where code]) (-> [Cursor Text] (R;Result [[Cursor Text] Code])) - (case (p;run [+0 code] (parse-ast where)) + (case (p;run [+0 code] (ast where)) (#R;Error error) (#R;Error error) |