manual: remove "Writing Nix Expressions" chapter

it is out of date, all over the place in level of detail, is really
about `nixpkgs`, and in general instructions should not be part of
a reference manual.

also:
- update redirects and internal links
- use "Nix language" consistently

1 files changed, 100 insertions, 107 deletions

diff --git a/doc/manual/redirects.js b/doc/manual/redirects.js
index 19f928c7e..167e221b8 100644
--- a/doc/manual/redirects.js
+++ b/doc/manual/redirects.js
@@ -132,113 +132,106 @@ var redirects = {
   "#sec-common-options": "command-ref/opt-common.html",
   "#ch-utilities": "command-ref/utilities.html",
   "#chap-hacking": "contributing/hacking.html",
-  "#adv-attr-allowSubstitutes": "expressions/advanced-attributes.html#adv-attr-allowSubstitutes",
-  "#adv-attr-allowedReferences": "expressions/advanced-attributes.html#adv-attr-allowedReferences",
-  "#adv-attr-allowedRequisites": "expressions/advanced-attributes.html#adv-attr-allowedRequisites",
-  "#adv-attr-disallowedReferences": "expressions/advanced-attributes.html#adv-attr-disallowedReferences",
-  "#adv-attr-disallowedRequisites": "expressions/advanced-attributes.html#adv-attr-disallowedRequisites",
-  "#adv-attr-exportReferencesGraph": "expressions/advanced-attributes.html#adv-attr-exportReferencesGraph",
-  "#adv-attr-impureEnvVars": "expressions/advanced-attributes.html#adv-attr-impureEnvVars",
-  "#adv-attr-outputHash": "expressions/advanced-attributes.html#adv-attr-outputHash",
-  "#adv-attr-outputHashAlgo": "expressions/advanced-attributes.html#adv-attr-outputHashAlgo",
-  "#adv-attr-outputHashMode": "expressions/advanced-attributes.html#adv-attr-outputHashMode",
-  "#adv-attr-passAsFile": "expressions/advanced-attributes.html#adv-attr-passAsFile",
-  "#adv-attr-preferLocalBuild": "expressions/advanced-attributes.html#adv-attr-preferLocalBuild",
-  "#fixed-output-drvs": "expressions/advanced-attributes.html#adv-attr-outputHash",
-  "#sec-advanced-attributes": "expressions/advanced-attributes.html",
-  "#sec-arguments": "expressions/arguments-variables.html",
-  "#sec-build-script": "expressions/build-script.html",
-  "#builtin-abort": "expressions/builtins.html#builtins-abort",
-  "#builtin-add": "expressions/builtins.html#builtins-add",
-  "#builtin-all": "expressions/builtins.html#builtins-all",
-  "#builtin-any": "expressions/builtins.html#builtins-any",
-  "#builtin-attrNames": "expressions/builtins.html#builtins-attrNames",
-  "#builtin-attrValues": "expressions/builtins.html#builtins-attrValues",
-  "#builtin-baseNameOf": "expressions/builtins.html#builtins-baseNameOf",
-  "#builtin-bitAnd": "expressions/builtins.html#builtins-bitAnd",
-  "#builtin-bitOr": "expressions/builtins.html#builtins-bitOr",
-  "#builtin-bitXor": "expressions/builtins.html#builtins-bitXor",
-  "#builtin-builtins": "expressions/builtins.html#builtins-builtins",
-  "#builtin-compareVersions": "expressions/builtins.html#builtins-compareVersions",
-  "#builtin-concatLists": "expressions/builtins.html#builtins-concatLists",
-  "#builtin-concatStringsSep": "expressions/builtins.html#builtins-concatStringsSep",
-  "#builtin-currentSystem": "expressions/builtins.html#builtins-currentSystem",
-  "#builtin-deepSeq": "expressions/builtins.html#builtins-deepSeq",
-  "#builtin-derivation": "expressions/builtins.html#builtins-derivation",
-  "#builtin-dirOf": "expressions/builtins.html#builtins-dirOf",
-  "#builtin-div": "expressions/builtins.html#builtins-div",
-  "#builtin-elem": "expressions/builtins.html#builtins-elem",
-  "#builtin-elemAt": "expressions/builtins.html#builtins-elemAt",
-  "#builtin-fetchGit": "expressions/builtins.html#builtins-fetchGit",
-  "#builtin-fetchTarball": "expressions/builtins.html#builtins-fetchTarball",
-  "#builtin-fetchurl": "expressions/builtins.html#builtins-fetchurl",
-  "#builtin-filterSource": "expressions/builtins.html#builtins-filterSource",
-  "#builtin-foldl-prime": "expressions/builtins.html#builtins-foldl-prime",
-  "#builtin-fromJSON": "expressions/builtins.html#builtins-fromJSON",
-  "#builtin-functionArgs": "expressions/builtins.html#builtins-functionArgs",
-  "#builtin-genList": "expressions/builtins.html#builtins-genList",
-  "#builtin-getAttr": "expressions/builtins.html#builtins-getAttr",
-  "#builtin-getEnv": "expressions/builtins.html#builtins-getEnv",
-  "#builtin-hasAttr": "expressions/builtins.html#builtins-hasAttr",
-  "#builtin-hashFile": "expressions/builtins.html#builtins-hashFile",
-  "#builtin-hashString": "expressions/builtins.html#builtins-hashString",
-  "#builtin-head": "expressions/builtins.html#builtins-head",
-  "#builtin-import": "expressions/builtins.html#builtins-import",
-  "#builtin-intersectAttrs": "expressions/builtins.html#builtins-intersectAttrs",
-  "#builtin-isAttrs": "expressions/builtins.html#builtins-isAttrs",
-  "#builtin-isBool": "expressions/builtins.html#builtins-isBool",
-  "#builtin-isFloat": "expressions/builtins.html#builtins-isFloat",
-  "#builtin-isFunction": "expressions/builtins.html#builtins-isFunction",
-  "#builtin-isInt": "expressions/builtins.html#builtins-isInt",
-  "#builtin-isList": "expressions/builtins.html#builtins-isList",
-  "#builtin-isNull": "expressions/builtins.html#builtins-isNull",
-  "#builtin-isString": "expressions/builtins.html#builtins-isString",
-  "#builtin-length": "expressions/builtins.html#builtins-length",
-  "#builtin-lessThan": "expressions/builtins.html#builtins-lessThan",
-  "#builtin-listToAttrs": "expressions/builtins.html#builtins-listToAttrs",
-  "#builtin-map": "expressions/builtins.html#builtins-map",
-  "#builtin-match": "expressions/builtins.html#builtins-match",
-  "#builtin-mul": "expressions/builtins.html#builtins-mul",
-  "#builtin-parseDrvName": "expressions/builtins.html#builtins-parseDrvName",
-  "#builtin-path": "expressions/builtins.html#builtins-path",
-  "#builtin-pathExists": "expressions/builtins.html#builtins-pathExists",
-  "#builtin-placeholder": "expressions/builtins.html#builtins-placeholder",
-  "#builtin-readDir": "expressions/builtins.html#builtins-readDir",
-  "#builtin-readFile": "expressions/builtins.html#builtins-readFile",
-  "#builtin-removeAttrs": "expressions/builtins.html#builtins-removeAttrs",
-  "#builtin-replaceStrings": "expressions/builtins.html#builtins-replaceStrings",
-  "#builtin-seq": "expressions/builtins.html#builtins-seq",
-  "#builtin-sort": "expressions/builtins.html#builtins-sort",
-  "#builtin-split": "expressions/builtins.html#builtins-split",
-  "#builtin-splitVersion": "expressions/builtins.html#builtins-splitVersion",
-  "#builtin-stringLength": "expressions/builtins.html#builtins-stringLength",
-  "#builtin-sub": "expressions/builtins.html#builtins-sub",
-  "#builtin-substring": "expressions/builtins.html#builtins-substring",
-  "#builtin-tail": "expressions/builtins.html#builtins-tail",
-  "#builtin-throw": "expressions/builtins.html#builtins-throw",
-  "#builtin-toFile": "expressions/builtins.html#builtins-toFile",
-  "#builtin-toJSON": "expressions/builtins.html#builtins-toJSON",
-  "#builtin-toPath": "expressions/builtins.html#builtins-toPath",
-  "#builtin-toString": "expressions/builtins.html#builtins-toString",
-  "#builtin-toXML": "expressions/builtins.html#builtins-toXML",
-  "#builtin-trace": "expressions/builtins.html#builtins-trace",
-  "#builtin-tryEval": "expressions/builtins.html#builtins-tryEval",
-  "#builtin-typeOf": "expressions/builtins.html#builtins-typeOf",
-  "#ssec-builtins": "expressions/builtins.html",
-  "#attr-system": "expressions/derivations.html#attr-system",
-  "#ssec-derivation": "expressions/derivations.html",
-  "#ch-expression-language": "expressions/expression-language.html",
-  "#sec-expression-syntax": "expressions/expression-syntax.html",
-  "#sec-generic-builder": "expressions/generic-builder.html",
-  "#sec-constructs": "expressions/language-constructs.html",
-  "#sect-let-expressions": "expressions/language-constructs.html#let-expressions",
-  "#ss-functions": "expressions/language-constructs.html#functions",
-  "#sec-language-operators": "expressions/language-operators.html",
-  "#table-operators": "expressions/language-operators.html",
-  "#ssec-values": "expressions/language-values.html",
-  "#sec-building-simple": "expressions/simple-building-testing.html",
-  "#ch-simple-expression": "expressions/simple-expression.html",
-  "#chap-writing-nix-expressions": "expressions/writing-nix-expressions.html",
+  "#adv-attr-allowSubstitutes": "language/advanced-attributes.html#adv-attr-allowSubstitutes",
+  "#adv-attr-allowedReferences": "language/advanced-attributes.html#adv-attr-allowedReferences",
+  "#adv-attr-allowedRequisites": "language/advanced-attributes.html#adv-attr-allowedRequisites",
+  "#adv-attr-disallowedReferences": "language/advanced-attributes.html#adv-attr-disallowedReferences",
+  "#adv-attr-disallowedRequisites": "language/advanced-attributes.html#adv-attr-disallowedRequisites",
+  "#adv-attr-exportReferencesGraph": "language/advanced-attributes.html#adv-attr-exportReferencesGraph",
+  "#adv-attr-impureEnvVars": "language/advanced-attributes.html#adv-attr-impureEnvVars",
+  "#adv-attr-outputHash": "language/advanced-attributes.html#adv-attr-outputHash",
+  "#adv-attr-outputHashAlgo": "language/advanced-attributes.html#adv-attr-outputHashAlgo",
+  "#adv-attr-outputHashMode": "language/advanced-attributes.html#adv-attr-outputHashMode",
+  "#adv-attr-passAsFile": "language/advanced-attributes.html#adv-attr-passAsFile",
+  "#adv-attr-preferLocalBuild": "language/advanced-attributes.html#adv-attr-preferLocalBuild",
+  "#fixed-output-drvs": "language/advanced-attributes.html#adv-attr-outputHash",
+  "#sec-advanced-attributes": "language/advanced-attributes.html",
+  "#builtin-abort": "language/builtins.html#builtins-abort",
+  "#builtin-add": "language/builtins.html#builtins-add",
+  "#builtin-all": "language/builtins.html#builtins-all",
+  "#builtin-any": "language/builtins.html#builtins-any",
+  "#builtin-attrNames": "language/builtins.html#builtins-attrNames",
+  "#builtin-attrValues": "language/builtins.html#builtins-attrValues",
+  "#builtin-baseNameOf": "language/builtins.html#builtins-baseNameOf",
+  "#builtin-bitAnd": "language/builtins.html#builtins-bitAnd",
+  "#builtin-bitOr": "language/builtins.html#builtins-bitOr",
+  "#builtin-bitXor": "language/builtins.html#builtins-bitXor",
+  "#builtin-builtins": "language/builtins.html#builtins-builtins",
+  "#builtin-compareVersions": "language/builtins.html#builtins-compareVersions",
+  "#builtin-concatLists": "language/builtins.html#builtins-concatLists",
+  "#builtin-concatStringsSep": "language/builtins.html#builtins-concatStringsSep",
+  "#builtin-currentSystem": "language/builtins.html#builtins-currentSystem",
+  "#builtin-deepSeq": "language/builtins.html#builtins-deepSeq",
+  "#builtin-derivation": "language/builtins.html#builtins-derivation",
+  "#builtin-dirOf": "language/builtins.html#builtins-dirOf",
+  "#builtin-div": "language/builtins.html#builtins-div",
+  "#builtin-elem": "language/builtins.html#builtins-elem",
+  "#builtin-elemAt": "language/builtins.html#builtins-elemAt",
+  "#builtin-fetchGit": "language/builtins.html#builtins-fetchGit",
+  "#builtin-fetchTarball": "language/builtins.html#builtins-fetchTarball",
+  "#builtin-fetchurl": "language/builtins.html#builtins-fetchurl",
+  "#builtin-filterSource": "language/builtins.html#builtins-filterSource",
+  "#builtin-foldl-prime": "language/builtins.html#builtins-foldl-prime",
+  "#builtin-fromJSON": "language/builtins.html#builtins-fromJSON",
+  "#builtin-functionArgs": "language/builtins.html#builtins-functionArgs",
+  "#builtin-genList": "language/builtins.html#builtins-genList",
+  "#builtin-getAttr": "language/builtins.html#builtins-getAttr",
+  "#builtin-getEnv": "language/builtins.html#builtins-getEnv",
+  "#builtin-hasAttr": "language/builtins.html#builtins-hasAttr",
+  "#builtin-hashFile": "language/builtins.html#builtins-hashFile",
+  "#builtin-hashString": "language/builtins.html#builtins-hashString",
+  "#builtin-head": "language/builtins.html#builtins-head",
+  "#builtin-import": "language/builtins.html#builtins-import",
+  "#builtin-intersectAttrs": "language/builtins.html#builtins-intersectAttrs",
+  "#builtin-isAttrs": "language/builtins.html#builtins-isAttrs",
+  "#builtin-isBool": "language/builtins.html#builtins-isBool",
+  "#builtin-isFloat": "language/builtins.html#builtins-isFloat",
+  "#builtin-isFunction": "language/builtins.html#builtins-isFunction",
+  "#builtin-isInt": "language/builtins.html#builtins-isInt",
+  "#builtin-isList": "language/builtins.html#builtins-isList",
+  "#builtin-isNull": "language/builtins.html#builtins-isNull",
+  "#builtin-isString": "language/builtins.html#builtins-isString",
+  "#builtin-length": "language/builtins.html#builtins-length",
+  "#builtin-lessThan": "language/builtins.html#builtins-lessThan",
+  "#builtin-listToAttrs": "language/builtins.html#builtins-listToAttrs",
+  "#builtin-map": "language/builtins.html#builtins-map",
+  "#builtin-match": "language/builtins.html#builtins-match",
+  "#builtin-mul": "language/builtins.html#builtins-mul",
+  "#builtin-parseDrvName": "language/builtins.html#builtins-parseDrvName",
+  "#builtin-path": "language/builtins.html#builtins-path",
+  "#builtin-pathExists": "language/builtins.html#builtins-pathExists",
+  "#builtin-placeholder": "language/builtins.html#builtins-placeholder",
+  "#builtin-readDir": "language/builtins.html#builtins-readDir",
+  "#builtin-readFile": "language/builtins.html#builtins-readFile",
+  "#builtin-removeAttrs": "language/builtins.html#builtins-removeAttrs",
+  "#builtin-replaceStrings": "language/builtins.html#builtins-replaceStrings",
+  "#builtin-seq": "language/builtins.html#builtins-seq",
+  "#builtin-sort": "language/builtins.html#builtins-sort",
+  "#builtin-split": "language/builtins.html#builtins-split",
+  "#builtin-splitVersion": "language/builtins.html#builtins-splitVersion",
+  "#builtin-stringLength": "language/builtins.html#builtins-stringLength",
+  "#builtin-sub": "language/builtins.html#builtins-sub",
+  "#builtin-substring": "language/builtins.html#builtins-substring",
+  "#builtin-tail": "language/builtins.html#builtins-tail",
+  "#builtin-throw": "language/builtins.html#builtins-throw",
+  "#builtin-toFile": "language/builtins.html#builtins-toFile",
+  "#builtin-toJSON": "language/builtins.html#builtins-toJSON",
+  "#builtin-toPath": "language/builtins.html#builtins-toPath",
+  "#builtin-toString": "language/builtins.html#builtins-toString",
+  "#builtin-toXML": "language/builtins.html#builtins-toXML",
+  "#builtin-trace": "language/builtins.html#builtins-trace",
+  "#builtin-tryEval": "language/builtins.html#builtins-tryEval",
+  "#builtin-typeOf": "language/builtins.html#builtins-typeOf",
+  "#ssec-builtins": "language/builtins.html",
+  "#attr-system": "language/derivations.html#attr-system",
+  "#ssec-derivation": "language/derivations.html",
+  "#ch-expression-language": "language/index.html",
+  "#sec-constructs": "language/constructs.html",
+  "#sect-let-language": "language/constructs.html#let-language",
+  "#ss-functions": "language/constructs.html#functions",
+  "#sec-language-operators": "language/operators.html",
+  "#table-operators": "language/operators.html",
+  "#ssec-values": "language/values.html",
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   "#gloss-derivation": "glossary.html#gloss-derivation",
   "#gloss-deriver": "glossary.html#gloss-deriver",