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fix spelling errors (#164)
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README.md
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README.md
@ -10,7 +10,7 @@ Since this library only supports C++17 compilers, please make sure that compiler
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You can also try the online version, PEG Playground at https://yhirose.github.io/cpp-peglib.
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You can also try the online version, PEG Playground at https://yhirose.github.io/cpp-peglib.
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The PEG syntax is well described on page 2 in the [document](http://www.brynosaurus.com/pub/lang/peg.pdf) by Bran Ford. *cpp-peglib* also supports the following additional syntax for now:
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The PEG syntax is well described on page 2 in the [document](http://www.brynosaurus.com/pub/lang/peg.pdf) by Bryan Ford. *cpp-peglib* also supports the following additional syntax for now:
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* `'...'i` (Case-insensitive literal operator)
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* `'...'i` (Case-insensitive literal operator)
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* `[^...]` (Negated character class operator)
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* `[^...]` (Negated character class operator)
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@ -39,7 +39,7 @@ This library supports the linear-time parsing known as the [*Packrat*](http://pd
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How to use
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How to use
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----------
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----------
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This is a simple calculator sample. It shows how to define grammar, associate samantic actions to the grammar, and handle semantic values.
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This is a simple calculator sample. It shows how to define grammar, associate semantic actions to the grammar, and handle semantic values.
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```cpp
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```cpp
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// (1) Include the header file
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// (1) Include the header file
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@ -132,7 +132,7 @@ There are four semantic actions available:
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- Semantic values
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- Semantic values
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- Matched string information
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- Matched string information
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- Token information if the rule is literal or uses a token boundary operator
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- Token information if the rule is literal or uses a token boundary operator
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- Choice number when the rule is 'prioritized choise'
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- Choice number when the rule is 'prioritized choice'
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`any& dt` is a 'read-write' context data which can be used for whatever purposes. The initial context data is set in `peg::parser::parse` method.
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`any& dt` is a 'read-write' context data which can be used for whatever purposes. The initial context data is set in `peg::parser::parse` method.
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@ -169,7 +169,7 @@ struct SemanticValues : protected std::vector<any>
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}
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}
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```
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```
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The following example uses `<` ... ` >` operator, which is *token boundary* operator.
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The following example uses `<` ... `>` operator, which is *token boundary* operator.
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```cpp
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```cpp
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peg::parser parser(R"(
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peg::parser parser(R"(
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@ -234,7 +234,7 @@ ret = parser.parse("200", val);
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assert(ret == false);
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assert(ret == false);
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```
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```
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*enter* and *leave* actions are also avalable.
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*enter* and *leave* actions are also available.
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```cpp
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```cpp
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parser["RULE"].enter = [](const char* s, size_t n, any& dt) {
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parser["RULE"].enter = [](const char* s, size_t n, any& dt) {
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@ -420,7 +420,7 @@ AST generation
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*cpp-peglib* is able to generate an AST (Abstract Syntax Tree) when parsing. `enable_ast` method on `peg::parser` class enables the feature.
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*cpp-peglib* is able to generate an AST (Abstract Syntax Tree) when parsing. `enable_ast` method on `peg::parser` class enables the feature.
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NOTE: An AST node holds a corresponding token as `std::string_vew` for performance and less memory usage. It is users' responsibility to kepp the original source text along with the generated AST tree.
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NOTE: An AST node holds a corresponding token as `std::string_vew` for performance and less memory usage. It is users' responsibility to keep the original source text along with the generated AST tree.
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```
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```
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peg::parser parser(R"(
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peg::parser parser(R"(
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@ -450,7 +450,7 @@ See actual usages in the [AST calculator example](https://github.com/yhirose/cpp
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Make a parser with parser combinators
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Make a parser with parser combinators
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-------------------------------------
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-------------------------------------
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Instead of makeing a parser by parsing PEG syntax text, we can also construct a parser by hand with *parser combinatorss*. Here is an example:
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Instead of making a parser by parsing PEG syntax text, we can also construct a parser by hand with *parser combinators*. Here is an example:
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```cpp
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```cpp
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using namespace peg;
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using namespace peg;
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@ -524,9 +524,9 @@ cpp-peglib accepts UTF8 text. `.` matches a Unicode codepoint. Also, it supports
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Error report and recovery
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Error report and recovery
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-------------------------
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-------------------------
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cpp-peglib supports the furthest failure error posision report as descrived in the Bryan Ford original document.
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cpp-peglib supports the furthest failure error position report as described in the Bryan Ford original document.
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For better error report and recovery, cpp-peglib supports 'recovery' operator with label which can be assosiated with a recovery expression and a custom error message. This idea comes from the fantastic ["Syntax Error Recovery in Parsing Expression Grammars"](https://arxiv.org/pdf/1806.11150.pdf) paper by Sergio Medeiros and Fabio Mascarenhas.
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For better error report and recovery, cpp-peglib supports 'recovery' operator with label which can be associated with a recovery expression and a custom error message. This idea comes from the fantastic ["Syntax Error Recovery in Parsing Expression Grammars"](https://arxiv.org/pdf/1806.11150.pdf) paper by Sergio Medeiros and Fabio Mascarenhas.
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The custom message supports `%t` which is a place holder for the unexpected token, and `%c` for the unexpected Unicode char.
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The custom message supports `%t` which is a place holder for the unexpected token, and `%c` for the unexpected Unicode char.
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@ -555,12 +555,12 @@ NAME ← < [a-zA-Z_][a-zA-Z_0-9]* >
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%word ← NAME
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%word ← NAME
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# Recovery operator labels
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# Recovery operator labels
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semia ← '' { message "missing simicolon in assignment." }
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semia ← '' { message "missing semicolon in assignment." }
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stmtb ← (!(Stmt / 'else' / '}') .)* { message "invalid statement" }
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stmtb ← (!(Stmt / 'else' / '}') .)* { message "invalid statement" }
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condw ← &'==' ('==' RelExp)* / &'<' ('<' AddExp)* / (!')' .)*
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condw ← &'==' ('==' RelExp)* / &'<' ('<' AddExp)* / (!')' .)*
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```
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```
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For instance, `';'^semi` is a syntactic sugar for `(';' / %recovery(semi))`. `%recover` operator tries to recover the error at ';' by skipping input text with the recovery expression `semi`. Also `semi` is assosiated with a custom message "missing simicolon in assignment.".
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For instance, `';'^semi` is a syntactic sugar for `(';' / %recovery(semi))`. `%recover` operator tries to recover the error at ';' by skipping input text with the recovery expression `semi`. Also `semi` is associated with a custom message "missing semicolon in assignment.".
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Here is the result:
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Here is the result:
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@ -580,11 +580,11 @@ public class Example {
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> peglint java.peg sample.java
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> peglint java.peg sample.java
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sample.java:5:12: syntax error, unexpected '<', expecting <NAME>, <NUMBER>, <WhileStmt>.
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sample.java:5:12: syntax error, unexpected '<', expecting <NAME>, <NUMBER>, <WhileStmt>.
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sample.java:8:5: missing simicolon in assignment.
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sample.java:8:5: missing semicolon in assignment.
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sample.java:8:6: invalid statement
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sample.java:8:6: invalid statement
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```
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```
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As you can see, it can now show more than one error, and provide more meaningfull error messages than the default messages.
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As you can see, it can now show more than one error, and provide more meaningful error messages than the default messages.
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peglint - PEG syntax lint utility
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peglint - PEG syntax lint utility
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---------------------------------
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---------------------------------
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@ -604,8 +604,8 @@ usage: grammar_file_path [source_file_path]
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--source: source text
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--source: source text
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--packrat: enable packrat memoise
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--packrat: enable packrat memoise
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--ast: show AST tree
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--ast: show AST tree
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--opt, --opt-all: optimaze all AST nodes except nodes selected with `no_ast_opt` instruction
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--opt, --opt-all: optimize all AST nodes except nodes selected with `no_ast_opt` instruction
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--opt-only: optimaze only AST nodes selected with `no_ast_opt` instruction
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--opt-only: optimize only AST nodes selected with `no_ast_opt` instruction
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--trace: show trace messages
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--trace: show trace messages
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```
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```
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@ -78,8 +78,8 @@ int main(int argc, const char **argv) {
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--source: source text
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--source: source text
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--packrat: enable packrat memoise
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--packrat: enable packrat memoise
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--ast: show AST tree
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--ast: show AST tree
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--opt, --opt-all: optimaze all AST nodes except nodes selected with `no_ast_opt` instruction
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--opt, --opt-all: optimize all AST nodes except nodes selected with `no_ast_opt` instruction
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--opt-only: optimaze only AST nodes selected with `no_ast_opt` instruction
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--opt-only: optimize only AST nodes selected with `no_ast_opt` instruction
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--trace: show trace messages
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--trace: show trace messages
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)";
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)";
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